Sensory Individuals: Unimodal and Multimodal Perspectives provides an interdisciplinary, well-balanced, and comprehensive look at different aspects of unisensory and multisensory objects, using both nuanced philosophical analysis and informed empirical work. The research presented in this book represents the field's progression from treating neural sensory processes as primarily modality-specific towards its current state of the art, according to which perception, and its supporting neural processes, are multi-modal, modality-independent, meta-modal, and task-dependent. Even within such approaches (...) sensory stimuli, properties, brain activations, and corresponding perceptual phenomenology can still be characterized in a modality-specific way. The book examines the basic building blocks of human perception, and whether they are best understood as sense modality dependent units of different forms or multimodal perceptual objects. The book combines a variety of innovative and integrative angles to explore the topic and acts as a catalyst for an increasingly diverse field of research, which is in an exciting phase of growth and advancement. New questions are arising as quickly as they are being answered, and the collection Sensory Individuals provides an original and up-to-date addition to the field. (shrink)

This collection of new essays on sensory individuals in unimodal and multimodal perception features contributions by outstanding researchers in the fields of philosophy of perception, experimental psychology, and cognitive neuroscience. The topics investigated include conceptual, developmental, and methodological aspects of object perception, and especially how various sense modalities construct their objects from sensory features and feature bearers. The interdisciplinary approach offered has enabled new directions in research on this subject. As ordered in this (...) volume, the topics of the contributions progress from treating neural sensory processes as primarily unisensory towards approaches that take perceptual processing to be modality-independent, meta-modal, and multimodal. Even within these latter approaches, sensory stimuli, sensory properties, brain activations, and corresponding perceptual phenomenology have often been characterized in a modality-specific way. Thus, it is timely to explore the relation between those processes that are unisensory and those that are multisensory. One of the primary themes of this collection is examining whether the basic building blocks of human perception are best understood as modality-dependent units of different forms or in terms of multimodal perceptual objects. Another theme is the relation between low-level object processing (segmentation and perceptual grouping processes) and high-level object knowledge embracing object concept and object-related expectations. A final theme is the role that perceptual objects play as loci of unification in unimodal and multimodal perception, namely that they enable binding and integration of sensory properties to individual entities or events. (shrink)

Sensory Individuals: Unimodal and Multimodal Perspectives provides an interdisciplinary, well-balanced, and comprehensive look at different aspects of unisensory and multisensory objects, using both nuanced philosophical analysis and informed empirical work. The research presented in this book represents the field's progression from treating neural sensory processes as primarily modality-specific towards its current state of the art, according to which perception, and its supporting neural processes, are multi-modal, modality-independent, meta-modal, and task-dependent. Even within such approaches (...) sensory stimuli, properties, brain activations, and corresponding perceptual phenomenology can still be characterized in a modality-specific way. The book examines the basic building blocks of human perception, and whether they are best understood as sense modality dependent units of different forms or multimodal perceptual objects. The book combines a variety of innovative and integrative angles to explore the topic and acts as a catalyst for an increasingly diverse field of research, which is in an exciting phase of growth and advancement. New questions are arising as quickly as they are being answered, and the collection Sensory Individuals provides an original and up-to-date addition to the field. (shrink)

This chapter examines how our sense modalities interact in the perception of persistence. The chapter concentrates on two questions. The first concerns perceptual processing—do perceptual computations of object persistence ever integrate and compute over representations from more than one modality? It argues that this question should be answered affirmatively. The second question concerns perceptual experience—do experiences of object persistence ever exhibit a constitutively multisensory phenomenal character, or is the phenomenology of (...) class='Hi'>object persistence always uniquely associated with just one modality? The chapter argues that the available evidence underdetermines the answer to this question, but suggests ways it might be empirically resolved. (shrink)

This chapter distinguishes between two kinds of ordinary multisensory experience that go beyond mere co-consciousness of features (e.g., the experience that results from concurrently hearing a sound in the hallway and seeing the cup on the table). In one case, a sensory experience in one modality creates a perceptual demonstrative to whose referent qualities are attributed in another sensory modality. For example, when you hear someone speak, auditory experience attributes audible qualities to a seen (...) event, a person’s speaking motions. The second kind of multisensory experience attributes features experienced in several sensory modalities to one and the same object via a process of amodal perceptual integration, i.e., integration that occurs separately from processing within the individual sensory modalities. Multisensory experiences arising from holding and seeing a tomato or from seeing the Indian curry boil and smelling it are examples of the second kind of multisensory experience. At the end of the chapter we look at synesthesia, a kind of atypical multisensory experience, and argue that one version of this phenomenon may be able to shed light on the neural mechanism underlying amodally integrated multisensory experience. (shrink)

Amodal completion is usually characterized as the representation of those parts of the perceived object that we get no sensory stimulation from. In the case of the visual sense modality, for example, amodal completion is the representation of occluded parts of objects we see. I argue that relationalism about perception, the view that perceptual experience is constituted by the relation to the perceived object, cannot give a coherent account of amodal (...) completion. The relationalist has two options: construe the perceptual relation as the relation to the entire perceived object or as the relation to the unoccluded parts of the perceived object. I argue that neither of these options are viable. (shrink)

Visuo-motor adaptation to optical prisms displacing the visual scene (prism adaptation, PA) is a method used for investigating visuomotor plasticity in healthy individuals and, in clinical settings, for the rehabilitation of unilateral spatial neglect. In the standard paradigm, the adaptation phase involves repeated pointings to visual targets, while wearing optical prisms displacing the visual scene laterally. Here we explored differences in PA, and its aftereffects (AEs), as related to the sensory modality of the target. Visual, auditory, and (...) class='Hi'>multisensory - audio-visual - targets in the adaptation phase were used, while participants wore prisms displacing the visual field rightwards by 10◦. Proprioceptive, visual, visual-proprioceptive, auditory-proprioceptive straight-ahead shifts were measured. Pointing to auditory and to audio-visual targets in the adaptation phase produces proprioceptive, visual-proprioceptive, and auditory-proprioceptive AEs, as the typical visual targets did. This finding reveals that cross-modal plasticity effects involve both the auditory and the visual modality, and their interactions (Experiment 1). Even a shortened PA phase, requiring only 24 pointings to visual and audio-visual targets (Experiment 2), is sufficient to bring about AEs, as compared to the standard 92-pointings procedure. Finally, pointings to auditory targets cause AEs, although PA with a reduced number of pointings (24) to auditory targets brings about smaller AEs, as compared to the 92-pointings procedure (Experiment 3). Together, results from the three experiments extend to the auditory modality the sensorimotor plasticity underlying the typical AEs produced by PA to visual targets. Importantly, PA to auditory targets appears characterized by less accurate pointings and error correction, suggesting that the auditory component of the PA process may be less central to the building up of the AEs, than the sensorimotor pointing activity per se. These findings highlight both the effectiveness of a reduced number of pointings for bringing about AEs, and the possibility of inducing PA with auditory targets, which may be used as a compensatory route in patients with visual deficits. (shrink)

Higher animals need to identify and track material objects because they depend on interactions with them for nutrition, reproduction, and social interaction. This paper investigates the perception of material objects. It argues, first, that material objects are tagged, in all five external senses, as bearers of the features detected by them. This happens through a perceptual process, here entitled Generalized Completion, which creates the appearance of objects that have properties that transcend the activation of sensory receptors. The (...) paper shows, secondly, that material objects are privileged subjects for perceived motion and interaction. That is, they are perceived as subjects for these properties while their parts seem to be subjects only derivatively. Material objects are the only perceptual subjects that are both multisensory and privileged. (shrink)

Object perception deploys a suite of perceptual capacities that constrains attention, guides reidentification, subserves recognition, and anchors demonstrative thought. Objects for perception—perceptual objects—are the targets of such capacities. Characterizing perceptual objects for multisensory perception faces two puzzles. First is the diversity of objects across sensory modalities. Second is the unity of multisensory perceptual objects. This paper resolves the puzzles. Objects for perception are structured mereologically complex individuals. Perceptual (...) objects are items that bear perceptible features and have perceptible parts arranged to form a unified whole. This circumscribes the targets of object perception where neutral talk concerning intentional objects and objects of perception cannot. Nonetheless, it is more permissive than identifying perceptual objects with material bodies, which excludes too much and leans too heavily on vision. The account thus is tailored to capture the role of objects in perception beyond vision: tactual, auditory, and olfactory objects are individuals with differing structures. Its flexibility also enables the account to accommodate shared objects for multisensory perception: multisensory perceptual objects are mereologically complex individuals with hybrid structure. For instance, one can bimodally perceive a common whole with parts accessible to one but not both modalities. Each sense provides a partial perspective on a complex whole that is perceptible through the coordinated use of multiple senses. Understanding perceptual objects as structured mereologically complex individuals thus provides a theoretically useful notion of an object for multisensory perception that resolves the puzzles of diversity and of unity. (shrink)

Multisensory processing encompasses all of the various ways in which the presence of information in one sensory modality can adaptively influence the processing of information in a different modality. In Part I of this survey article, I begin by presenting a cartography of some of the more extensively investigated forms of multisensory processing, with a special focus on two distinct types of multisensory integration. I briefly discuss the conditions under which these different forms of (...) multisensory processing occur as well as their important perceptual consequences and interrelations. In Part II, I then turn to examining of some of the different possible ways in which the structure of conscious perceptual experience might also be characterized as multisensory. In addition, I discuss the significance of research on multisensory processing and multisensory consciousness for philosophical attempts to individuate the senses. (shrink)

Perceptual experience strikes us as a presentation of the here and now. I argue that it also involves experience of the past. This claim is often made based on cases, like seeing stars, involving significant signal-transmission lag, or based on how working memory allows us to experience extended events. I argue that the past is injected into perceptual experience via a third way: long-term memory traces in sensory circuits. Memory, like the receptor-based senses, is an integrated and (...) constituent modality through which we experience the environment. Because of this modality, we experience the sensed properties of stimuli partly as they are now, but also partly as we encountered them in the past. (shrink)

Chapter 1 First Person Access to Mental States. Mind Science and Subjective Qualities -/- Abstract. The philosophy of mind as we know it today starts with Ryle. What defines and at the same time differentiates it from the previous tradition of study on mind is the persuasion that any rigorous approach to mental phenomena must conform to the criteria of scientificity applied by the natural sciences, i.e. its investigations and results must be intersubjectively and publicly controllable. In Ryle’s view, philosophy (...) of mind needs to adopt an antimentalist stance to achieve this aim. Antimentalism not only definitively rejects the idea that mind is a substance separated from the body, it also denies that mental phenomena radically differ from physical phenomena by virtue of several unique features. Most problematically, mental phenomena have a conscious character (mental states are related to specific qualitative feelings) and are accessible only to the first-person (only the subject knows directly what s/he is experiencing inside his/her mind). Ryle takes a strong stance on antimentalism going so far as to maintain that an approach to mind which aims to meet the criteria of scientificity set by the natural sciences must avoid any reference to internal, unobservable mental states. In his view (which is considered a specifically philosophical version of psychological behaviorism and also addresses questions put forward in psychological research), mental states can be redescribed in terms of behavioral dispositions. In this chapter, we address the historical roots of the antimentalist view and analyze its relation to the later tradition of research on mind. We show that, compared to the antimentalist stance, functionalism and cognitivism take a step back when they maintain that direct reference to mental states is necessary since mental states cause and therefore explain human behavior. This step backwards is often interpreted as a return to mentalism. However, this is only partially true. Indeed, we suggest that these later traditions retain one important element of Ryle’s antimentalism, i.e. the idea that mental states must be uniquely identified using external and publicly observable criteria, while excluding any reference to introspection and those qualitative dimensions of a mental state, which are accessible only to the first-person. According to the perspective we put forward, this epistemological stance has continued to influence contemporary research on mind and current philosophical and psychological theories which both tend to exclude the subjective qualities of human experience from their accounts of how the mind works. The issue we raise here is whether this is legitimate or whether subjective qualities do play a role with respect to the way our mind works. The conclusion of this chapter anticipates the argument the book makes in in favor of this latter position, starting from a particular angle, i.e. the problem of how we categorize concepts related to our internal states. -/- Chapter 2 The Misleading Aspects of the Mind/Computer Analogy. The Grounding Problem and the Thorny Issue of Propriosensitive Information -/- Abstract. After the crisis of behaviorism, cognitivism and functionalism became the predominant models in the field of psychology and of philosophy, respectively. Their success is mainly due to the new key they use for interpreting mental processes: the mind/computer analogy. On the basis of this analogy, mental operations are seen as cognitive processes based on computations, i.e. on manipulations of abstract symbols which are in turn understood as informational unities (representations). This chapter identifies two main problems with this model. The first is how these symbols can relate to and communicate with perception and thus allow us to identify and classify what we perceive through the senses. Here we limit ourselves to presenting this issue in relation to the classical symbol grounding problem originally put forward by Harnad on the basis of Searle’s Chinese room argument. An attempt to address the problem raised here will be made in chap. 3. The second point we discuss in relation to the mind/computer analogy concerns the idea of information it fosters. Indeed, following this analogy, information is something available in the external world which can be captured by the senses and transmitted to the central system without being influenced or modified by the procedures of transmission. This perspective does not take into account that – unlike computers – in living beings information is acquired by means of the body. As Ulric Neisser has already pointed out, the body is itself an informational source that provides us with additional sensory experience that influences (modifies or complements) the information extracted from the external world by the senses. To develop this line of analysis and to determine exactly what information is provided by the body and how this might influence cognition, we examine Sherrington’s and Gibson’s positions. Moving on from their views, we qualify bodily information in terms of ‘proprioception’. We use ‘proprioception’ in a broad sense to describe any kind of experience we have of our internal states (including postural information as well as sensations related to the general state of the body and its parts). Following Damasio’s and Craig’s studies, we further elaborate this position, arguing that living beings are equipped with an internal propriosensitive monitoring system which maps all the changes that constantly occur in our body and that give us perceptual (‘proprioceptive’ or propriosensitive) information about what happens inside us. Moreover, relying on Goldie’s and Ratcliffe’s view, we show that emotional information can also be considered as a form of ‘proprioception’ which contributes to determining everything we perceive. This analysis leads us to the second main thesis of this book: ‘proprioception’ is a form of internal perception and it is an essential component of the sensory information we can access and use for all cognitive purposes. -/- Chapter 3 Semantic Competence from the Inside: Conceptual Architecture and Composition -/- Abstract. Concepts are essential constituents of thought: they are the instruments we use to categorize our experience, i.e. to classify things and group them together in homogeneous sets. Here we define concepts as the internal mental information (representations) that allows us, among other things, to master words in natural language. By analyzing the way in which individuals master word meanings we explore a number of hypotheses regarding the nature of concepts. Following Diego Marconi’s research, we differentiate between two kind of abilities that underpin lexical competence – so-called ‘referential’ and ‘inferential competence’ – and we suggest that, in order to support these abilities, concepts must also include two corresponding kinds of information, i.e. inferential and referential information. We point out that the most widely used and acknowledged theories of concepts do not make this distinction, instead broadly characterizing the information used for categorization in terms of propositionally described feature lists. However, we show that while feature lists can explain inferential competence, they do not account for referential competence. To address the issue of referential competence we examine Ray Jackendoff’s hypothesis that to account for the possibility of linking perceptual and conceptual information we need to assume the existence of a (visual) representation that encodes the geometric and topological properties of objects and bridges the gap between the percept and the concept. Furthermore, we analyze the extension of this work by Jesse Prinz who introduced the notion of a proxytype, a perceptual representation of a class of objects that incorporates structural and parametric information related to their appearance. However, as we point out, proxytypes can only explain the relationship between perception and concepts with respect to instances that can be perceived through the senses and that belong to the same class by virtue of their physical similarity. We suggest that this notion be extended to include larger conceptual classes. To accomplish this, we further develop Mark Johnson, George Lakoff and Jean Mandler’s idea of a schematic image and argue that conceptual representations include a perceptual schema. Perceptual schemata are non-linguistic, structured experiential gestalts (patterns or maps) that make use of information taken from all sensory modalities, including body perception. They accomplish a quasi-conceptual function: they allow us to recognize and to classify different instances. In this work, we hypothesize that perceptual schemata are an essential component of concepts, but not identical to them. Instead, we suggest that concepts include both perceptual and propositional information with perceptual schemata providing the ‘perceptual core concept’ that grounds related propositional information. -/- Chapter 4 In the Beginning There Were Categories. The Bodily Origin of Prelinguistic Categorical Organization: The Example of Folkbiological Taxonomies -/- Abstract. Studies of categorization in psychology and the cognitive sciences have made use of the notions of ‘category’ and ‘concept’ without precisely defining what is meant by either; in fact, often these terms have been used as synonyms, making it difficult to address specific issues related to conceptual development. This chapter begins by discussing the definitions of, as well as the distinctions between, ‘categories’ and ‘concepts’ in the classical philosophical tradition (Aristotle, Kant and Husserl). We introduce our view of categories with reference to Husserl. Categorization is defined as the way in which our experience is originally (pre-linguistically) organized in a passive and fully unconscious manner on the basis of universal structuring principles. Conceptualization is explained as a later process in which the earlier categorical macro-classes are further subdivided into more specific and detailed sets; this later process also relies on linguistic learning and exposure to culture. On the basis of Ray Jackendoff, Jean Mandler, George Lakoff and Mark Johnson’s work, we hypothesize that categorization is a two-step process that begins with the formation of homogeneous sets of entities partitioned into regions that describe the ontological boundaries of the objects that humans perceive (categories) and continues at a later stage with the development of more specific classifications (concepts). In this chapter, we mainly address three related issues: Why should we assume that there is categorical organization which precedes the development of a conceptual system? How do categories and concepts relate to each other? Shall we hypothesize that categories are innate or that they are formed before concepts on the basis of information and organizational structure available at a very early developmental stage? We show that categorical partitions are necessary for categorization and, following Mandler, that the general categories we form at an early age do not match our adult superordinate concepts. As for the third issue, we argue that there might be no need to assume that categories are innately present in the human mind, since their formation can be explained – at least in certain cases – by basic mechanisms that work on body (propriosensitive) information. This hypothesis will not be discussed in general, but in relation to a particularly relevant example of categorical partition, i.e. the folk-biological dichotomy between ANIMATE/INANIMATE. This is compared with other dichotomies that derive from it, but are not directly categorical such as LIVING/NON-LIVING and BIOLOGICAL/NON-BIOLOGICAL. -/- Chapter 5 Internal States: From Headache to Anger. Conceptualization and Semantic Mastery -/- Abstract. Here we ask if we can also apply the distinction between referential and inferential competence we introduced in Chapter 3 to words that do not refer to things that are perceived using the external senses, especially to words/concepts that denote bodily experiences (such as pain, thirst, hunger, etc.) or emotions. We introduce and discuss the hypothesis that – even though such words/concepts do not refer to intersubjectively identifiable entities in the external world – they do have a kind of referent that can be accessed via direct perception, more specifically ‘proprioception’, as we have defined it in terms of all propriosensitive information we can consciously access. In the first part of the chapter, we specifically consider terms denoting bodily experiences such as ‘pain’ or ‘hunger’ and argue that their referents are identified and classified from a first-personal point of view on the basis of four main characteristics: their specific intensity, their localization in the body, their co-occurrence with other signals and above all their specific qualitative sensations. Emotions are addressed in the second part of the chapter. We suggest that there is a continuity between bodily experiences and emotions. In particular, we argue for a perceptual theory of emotions in line with that proposed by James and Lange at the end of the 19th century and developed more recently by authors such as Damasio (see also chap. 2§5, §6). The hypothesis we put forward is that the referential information that supports the categorization of emotions and therefore also our mastery of terms referring to emotions consists in the perception (i.e. the ‘proprioception’) of those bodily states and changes in bodily states which constitute our emotional experience. In the context of this discussion we examine some objections to this line of reasoning that arise from a cognitivist perspective and following authors such as Oatley, Johnson-Laird and Frijda, we distinguish between basic emotions that can be identified and classified solely on the basis on how they feel and complex emotions whose identification and classification additionally depends on cognitive factors. To describe how emotions are identified and classified on the basis of how they feel, we rely on Marcel and Lambie’s distinction between an ‘emotion state’ and an ‘emotion experience’. Both notions indicate kinds of feelings that we consciously experience. However, they describe first-order and second order emotion awareness respectively. The emotion state is the feeling we have of the bodily states and changes that occur when we are experiencing an emotion, while the emotion experience is the fully developed and integrated emotion we both experience and are, with reflection, aware of experiencing. On the basis of this differentiation, we also show that the same characteristics that aid in the identification and classification of bodily experiences (specific qualitative sensations; somatic localization; specific intensity; presence/absence of specific concomitant sensations) can also be used for the identification and classification of emotions – at least basic emotions. In the last two sections of the chapter we present some clinical evidence on the semantic competence of people who suffer from Alexithymia and Autism Spectrum Disorder which supports the conclusions of our preceding analyses. -/- Chapter 6 The ‘Proprioceptive’ Component of Abstract Concepts -/- Abstract. In this chapter, we address the issue of whether the mastery of abstract words requires only inferential knowledge and thus, if the concepts that support the mastery of abstract words include only linguistic information. We start by differentiating the notions of ‘abstract’ and ‘general’ which are often erroneously confused. We then identify a strict definition of abstract, as contrasted with ‘concrete’, that applies to words or concepts whose referent cannot be experienced by the senses. We argue that abstract words/concepts would be better described as theoretical, because they are usually conceived as structured sets of inferential knowledge expressed linguistically; that is, as small theories. Pointing out parallels with Carnap’s analysis of this issue in philosophy of science, we hypothesize that words/concepts denoting non-observable entities are not all ‘equally theoretical’, because their link to sensory experience can be stronger or weaker. We revive the distinction, inspired by Quine, between theoretical and intertheoretical concepts/words. This distinction relies on the fact that the former – unlike the latter – retains a strong, although indirect, connection with perception. In Quine’s discussion, perception is understood uniquely in terms of observability, i.e. of external sensory experience. Here we argue, however, that bodily, ‘proprioceptive’ (i.e. propriosensitive) experience can also serve to referentially ground theoretical (i.e. abstract) concepts/words. We frame this issue using the example of the theoretical concept ‘freedom’ and Lakoff’s hypothesis that this concept is developed on the basis of bodily information. We contrast this with the example of ‘democracy’ which more closely resembles an intertheoretical concept/word. Furthermore, we show that one of the classical views put forward in psycholinguistic research to explain how abstract concepts are mentally represented – i.e. Paivio’s Dual Coding Theory – points in the same direction as our analysis. The same is true of Barsalou’s work suggesting that we use internal information to understand at least some abstract words. To sustain this position, we put forward two lines of evidence: the first comes from psycholinguistic studies while the second examines deficits of semantic competence exhibited by people with Autism Spectrum Disorder. On the basis of our analysis, we put forward a classification that distinguishes between different kinds of concreteness and different degrees of abstraction: concepts/words referring to body experiences and basic emotions are described as analogous to concrete concepts/words because they are grounded in perceptual (i.e. propriosensitive) experience, while abstract concepts/words are considered more or less abstract depending on whether they are intratheoretical (and rely entirely on inferential information) or theoretical (and are partially grounded in perceptual – or more often in propriosensitive perceptual – information). In the last section of the chapter we consider two scales that have been used in psycholinguistic research to measure the degree of concreteness vs. abstractness of words and we show that – used conjointly – they can provide a measure of the internal vs. external grounding of specific words. (shrink)

According to the decomposition thesis, perceptual experiences resolve without remainder into their different modality-specific components. Contrary to this view, I argue that certain cases of multisensory integration give rise to experiences representing features of a novel type. Through the coordinated use of bodily awareness—understood here as encompassing both proprioception and kinaesthesis—and the exteroceptive sensory modalities, one becomes perceptually responsive to spatial features whose instances couldn’t be represented by any of the contributing modalities functioning in isolation. (...) I develop an argument for this conclusion focusing on two cases: 3D shape perception in haptic touch and experiencing an object’s egocentric location in crossmodally accessible, environmental space. (shrink)

The Bayesian model of multisensory cue integration proposed by Ernst and Banks provides an attractive model for understanding a way that our sensory systems may interact. Moreover, it has been suggested that the process of multisensory integration that it models underpins conscious experiences with multisensory representational contents merged across modalities. Should we therefore take empirical support for the Bayesian model as evidence of the multimodality of perception? Focusing on evidence of integration across vision and touch, (...) I argue that apparent support for the model does not warrant the rejection of the view that each of our conscious perceptual experiences is associated with one and only one sense modality. (shrink)

My thesis is that perceptual awareness is richly multisensory. I argue for this conclusion on the grounds that certain forms of multisensory perceptual experience are incompatible with the claim that each aspect of a perceptual experience is associated with some specific sensory modality or another. First, I explicate what it is for some feature of a conscious perceptual episode to be modality specific. Then, I argue based on philosophical and (...) experimental evidence that some novel intermodal features are perceptible only through the coordinated use of multiple senses. I appeal to cases that involve consciously perceptible feature instances and feature types that could not be perceptually experienced through the use of individual sense modalities working on their own or simply in parallel and co-consciously. Finally, I offer an account of how to type perceptual experiences by modality that makes room for richly multisensory experiences. (shrink)

The integration of multisensory information is an essential mechanism in perception and action control. Research in multisensory integration is concerned with how the information from the different sensory modalities, such as the senses of vision, hearing, smell, taste, touch, and proprioception, are integrated to a coherent representation of objects (for an overview, see e.g., Calvert, Spence and Stein, 2004). The combination of information from the different senses is central for action control. For instance, when you grasp (...) for a rubber duck, you can see its size, feel its compliance and hear the sound it produces. Moreover, identical physical properties of an object can be provided by different senses. You can both see and feel the size of the rubber duck. Even when you grasp for the rubber duck with a tool (e.g., with tongs), the information from the proximal hand, from the effective part of the distal tool and from the eyes are integrated in a manner to act successfully (for limitations of this integration see Sutter et al., 2013).Over the recent decade a surge of interest in multisensory integration and action control has been witnessed, especially in connection with the idea of a statistically optimized integration of multiple sensory sources. The human information processing system is assumed to adjust moment-by-moment the relative contribution of each sense’s estimate to a multisensory task. The sense’s contribution depends on its variance, so that the total varia... (shrink)

This thesis mounts an attack against accounts of perceptual justification that attempt to analyze it in terms of evidential justifiers, and has defended the view that perceptual justification should rather be analyzed in terms of non-evidential justification. What matters most to perceptual justification is not a specific sort of evidence, be it experiential evidence or factive evidence, what matters is that the perceptual process from sensory input to belief output is reliable. I argue for (...) this conclusion in the following way. Chapter 1: The Arguments from HallucinationChapter 1 presents a skeptical argument from hallucination that starts from a premise about the alleged introspective indistinguishability of perception and hallucination, and concludes that perceptual knowledge is impossible. Underlying this argument are certain assumptions about the nature of perceptual justification, and different responses to the argument portray different views of perceptual justification. Evidentialism and dogmatism both reject the premise that appearances do not provide evidence sufficient for perceptual knowledge, although they disagree about the precise nature of the appearances. Epistemological disjunctivism rejects the premise that introspectively indistinguishable experiences provide the same evidence, while upholding the idea that some sort of evidence, namely factive evidence, is necessary for perceptual justification and knowledge. Process reliabilism rejects the premise that evidence is necessary for perceptual knowledge on the grounds that even perceptual justification can be obtained without evidence, as long as the cognitive process producing the belief is reliable.Chapter 2: EvidentialismChapter 2 starts by introducing some motivations for experientialist views of perceptual justification, such as evidentialism and dogmatism, which hold that conscious experiences evidentially justify perceptual beliefs. These motivations have to do with their ability to accommodate the New Evil Demon Intuition that demon-deceived subjects have justified perceptual beliefs and the Blindsight Intuition that blindsighters do not have justified perceptual beliefs. However, experientialist views are also faced with a Sellarsian dilemma: either experience is construed as non-propositional, but then the proposed evidential relation is unclear, or experience is construed as propositional, but then it is ad hoc to hold that they can evidentially justify without being justified themselves.Chapter 2 continues with a discussion of evidentialism, which grasps the first horn of this dilemma. I argue that evidentialism cannot adequately explain why a non-propositional experience constitutes evidence for this rather than that belief, and also does not provide any account of how to determine which belief fits an evidence-set which partly consists out of non-propositional experiences. Although a reliabilist version of evidentialism can provide a better account of these matters, it suffers from counter-intuitive predictions about justification and a conception of evidence that is so liberal that it could even include blindsighters and clairvoyants as having such evidence.Chapter 3: DogmatismChapter 3 focuses on variants of dogmatism, a theory of perceptual justification that grasps the second horn of the Sellarsian dilemma by holding that a perceptual experience with the content that p is sufficient for immediate prima facie justification of the belief that p. I first argue that dogmatism should identify perceptual experiences with high-level conscious states to accommodate the problem of novice vs. expert identification and the problem of the speckled hen. I then argue that this version of dogmatism still fails to meet a certain explanatory challenge which I dub the `Distinctiveness Problem'. Dogmatism should explain what is so distinctive about perceptual experience that enables it, in contrast with desire and imagination, to evidentially justify the belief that p without, in contrast with belief, being justified itself.Phenomenalist answers to this problem fail because they either do not provide a distinctive property of perceptual experience, or else provide a property that is reducible to or possibly caused by beliefs. In both cases, dogmatism would have the result that intuitively unjustifying experiences, such as imaginations, nevertheless become capable of justifying beliefs. Moreover, phenomenalists still need some explanation of why phenomenology is epistemically relevant at all.A new variant of the problem of the speckled hen is an intuitive illustration of this point against dogmatists. If a perceptual experience that p is not reliably connected to the fact that p or the belief that p, then beliefs based on this experience simply will not be intuitively justified. One possible response to this problem incorporates reliability into the content of experience in the sense that an experience cannot have the content that p if it is not reliably connected to both the fact that p and the belief that p. However, this will lose the motivation from the New Evil Demon Scenario, and will make large concessions towards reliabilism.Chapter 4: Epistemological DisjunctivismGiven these problems for experientialist views of perceptual justification, chapter 4 focuses on a different evidential account of justification: epistemological disjunctivism. According to the Justified True Belief version of Epistemological Disjunctivism, the fact that I see that p is the factive and reflectively accessible evidence in virtue of which I know that p. I argue that JTBED faces formidable problems: first, it cannot adequately deal with the basis problem, second, it cannot accommodate the New Evil Demon Intuition, third,it faces the problem of hyper-intellectualization, and fourth, it has no good account of reflective access.Knowledge First Epistemological Disjunctivism, in contrast, holds that seeing that p just is a way of knowing that p. The fact that I see that p constitutes my justification for believing that p, even though it is not necessary for my knowledge that p. Although this view solves most of the above problems, I argue that KFED still faces a challenge of its own: its notion of justification is so strong that justification entails knowledge but is not itself entailed by it. This means that it too faces a hyper-intellectualization objection because it cannot accommodate animal justification, and that it too will struggle to accommodate the New Evil Demon Intuition.Nevertheless, there is something to the epistemological disjunctivist idea that higher-order capabilities are important to perceptual justification. Specifically, higher-order capabilities provide one with a way of accommodating the Blindsight Intuition without appealing to the notion of experiential evidence: blindsighters are epistemically worse off than normal human perceivers because they lack higher-order beliefs about how they are gaining their information. If one holds that these higher-order beliefs provide a special sort of justification for perceptual beliefs, then blindsighters lack this type of justification. Chapter 5: Process ReliabilismAfter displaying the problems of several evidential accounts of perceptual justification, chapter 5 introduces a non-evidential account: process reliabilism. The classic version of this view holds that the reliability of a belief-forming process is necessary and sufficient for the prima facie justification of a specific set of beliefs, namely, those that arise out of belief-independent processes. Two classic major problems for this view consist of counterexamples to both the necessity and sufficiency of reliability for justification. Although the Generality Problem raises some difficulties for reliabilism, they do not appear to be insurmountable.The second part of chapter 5 focuses on a variety of process reliabilism, inferentialist reliabilism, that is explicitly aimed at responding to clairvoyance cases. According to inferentialist reliabilism, one should distinguish between basic and non-basic beliefs, where basic beliefs are those that result out of the non-inferential operation of an inferentially opaque cognitive system that developed in a natural way. Reliability is only sufficient for the justification of basic beliefs, while non-basic beliefs also require conditional reliability and justification of the beliefs on which they are based.This distinction between basic and non-basic beliefs is meant to answer the challenge arising out of clairvoyance cases because these are all supposedly cases in which the resulting beliefs arenon-basic. However, I argue that the beliefs in these cases come out as non-basic primarily because of the etiological constraint on cognitive systems, a constraint that is unfortunately undermotivated. It seems that beliefs can be justified even if they are produced by a cognitive system that developed by accident, or by a system that was artificially designed to produce those beliefs. So even though the inferentialist reliabilist might have a point in distinguishing between basic and non-basic beliefs, it is still in need of a different response to clairvoyance cases. Chapter 6: Rejoinders for ReliabilismChapter 6 improves on the inferentialist reliabilist account of justification by presenting a different way of dealing with the clairvoyance cases and New Evil Demon Scenario. I start from the empirically plausible idea that we know that we are perceiving when we are perceiving, not because of the use of experiential evidence, but rather, because of an unconscious source-monitoring mechanism. I then argue that the existence of such a source-monitoring mechanism could be used to explain why clairvoyance cases actually have to do with defeat rather than absence of prima facie justification: beliefs that pop up in our head should be recognized as stemming from untrustworthy sources, and so we acquire defeating higher-order beliefs about the first-order beliefs. I also argue that this defeat should be able to occur even if the higher-order beliefs are themselves unjustified. This defeater-account of clairvoyance is preferable to several externalist alternatives. Making reliability relative to a specific world seems rather ad hoc, and further requirements on justification, such as evidence-based belief, cognitively integrated belief, or properly produced belief, all appear unnecessary and are susceptible to adapted versions of the clairvoyance case.I further argue for an alternative inferentialist reliablist response to the New Evil Demon Intuition which treats it as mistaken rather than correct. The New Evil Demon Intuition might arise because of a mistaken view of actual perceptual justification as having to do with experiential evidence. This mistaken view could be explained by the fact that experience is actually reliably connected to belief and is often cited in response to a knowledge-challenge. If this is a correct analysis of the New Evil Demon Intuition, then there is an element of question-begging involved when this scenario is still pressed against inferentialist reliabilists who do not adhere to the experientialist assumption it presupposes.With the inferentialist reliabilist account in hand,we are able to see that many of the premises of the epistemological argument from hallucination are problematic. Evidence does not appear to be required for perceptual knowledge, as perceptual justification does not even require such evidence. Moreover, if we accept a reliabilist model of introspection, then we are often able to know on the basis of introspection that we are perceiving rather than hallucinating. Once one gets clear about the alternatives, it becomes apparent that the argument thrives on internalist assumptions about justification and knowledge that one need not accept. (shrink)

Philosophical discussion about the reality of sensory perceptions has been hijacked by two tendencies. First, talk about perception has been largely centered on vision. Second, the realism question is traditionally approached by attaching objects or material structures to matching contents of sensory perceptions. These tendencies have resulted in an argumentative impasse between realists and anti-realists, discussing the reliability of means by which the supposed causal information transfer from object to perceiver takes place. Concerning the nature of (...) sensory experiences and their capacity to provide access to reality, this article challenges the standard categories through which most arguments in this debate have been framed to date. Drawing on the underexplored case of olfaction, I first show how the details of the perception process determine the modalities of sensory experiences. I specifically examine the role of measurement and analyze its influence on the characterization of perceptions in olfaction. My aim is to argue for an understanding of perception through a process view, rather than one pertaining to objects and properties of objects. (shrink)

When I am looking at an apple, I perceptually attribute certain properties to certain entities. Two questions arise: what are these entities (what is it that I perceptually represent as having properties) and what are these properties (what properties I perceive this entity as having)? This paper is about the former, less widely explored, question: what does our perceptual system attribute properties to? In other words, what are these ‘sensory individuals’. There have been important debates in philosophy of (...) perception about what sensory individuals would be the most plausible candidates for which sense modalities. The aim of this paper is to ask a related question about picture perception: what is the sensory individual of picture perception? When we look at a picture and see an apple depicted in it, what kind of entity do we see? What do we perceptually attribute properties to? I argue that the most straightforward candidates (ordinary objects, sui generis sensory individuals, no sensory individuals) are all problematic and that the most plausible candidate for the sensory individuals of picture perception are spatiotemporal regions. (shrink)

Our emotional states affect how we perceive the world. If I am stressed, annoyed, or irritated, I might experience the sound of children laughing and screaming as they play around the house in a negative manner — it is unpleasant, loud, piercing, and so on. Yet, if I’m in a relaxed, happy, loving mood, the very same sounds might be experienced as pleasant, playful, warm, and so on. The sounds being made by the children are the same in both cases, (...) but how they are experienced differs. The auditory experience is affected by the emotional state that I am in. I perceive the sounds differently depending on how I’m feeling. Although this might at first seem to be a trivial observation, it certainly is not. We take for granted that our perceptual experiences give rise to justified beliefs and knowledge. Thus, if my perceptual experience of an object can differ based on my emotional state, and I take my perceptual experience to justify my beliefs and even lead to knowledge, then we might have a problem. If emotions — which are not fixed and in large part uncontrolled — affect our ability to accurately perceive the world, then they may undermine the justified beliefs and knowledge gained on the basis of our perceptual experience of the world. My goal here is to explore this potential problem. -/- I consider how we might understand the effect that emotions have on the justification of our perceptual beliefs about the world, beliefs that we acquire from a variety of sensory modalities — audition, gustation olfaction, and so on. I take the problem to be associated with one of two forms of perceptual influence: penetration or multisensory integration. In any given perceptual moment there are multiple sensory modalities and mental states at play, each affecting the overall experience. Whether we understand the influence of emotion on perception as a form of non-perceptual penetration or a form of non-visual sensory perception of the inner body — interoception — the potential epistemological difficulties remain: how can we be said to acquire justified beliefs and knowledge on the basis of such influenced perceptual experience. As has been the norm, only the five exteroceptive senses of vision, audition, olfaction, taste and touch are typically discussed in the context of sensory perception. However, as I argue, there is strong reason to accept the claim that emotional experience is a form of interoception, and that interoception ought to be considered when discussing sensory perception. In this way, then, I propose that clarifying the role played by interoception in sense perception across modalities is necessary if we are to make progress on the epistemological problems at hand. (shrink)

This volume is about the many ways we perceive. Contributors explore the nature of the individual senses, how and what they tell us about the world, and how they interrelate. They consider how the senses extract perceptual content from receptoral information. They consider what kinds of objects we perceive and whether multiple senses ever perceive a single event. They consider how many senses we have, what makes one sense distinct from another, and whether and why distinguishing senses may (...) be useful. They consider the extent to which the senses act in concert, rather than as discrete modalities, and whether this influence is epistemically pernicious, neutral, or beneficial. They explore both the familiar five sense modalities and other candidate sense modalities, including a sense for flavour, inner senses (e.g., a sense for pain), and various senses that may result from using sensory substitution devices. Contributors often represent competing views, and the methods they deploy sometimes differ from one essay to the next—with some drawing upon the sciences and engineering and others relying upon conceptual analysis. All contributors agree, nonetheless, that traditional theorizing about the senses is hampered by a neglect of the senses other than vision, and by the misconception that vision is a passive receptacle for an image thrown by a lens. And many contributors believe that it is unduly restrictive to think of perception as a collation of contents provided by individual sense modalities; they think that to understand perception properly, we need to build into our accounts the idea that the senses work together. The ambition of the volume is to begin to develop better paradigms for understanding the senses, and thereby to move toward a better understanding of perception. (shrink)

This dissertation proposes the central elements of a Social Enactive Theory of Perception. According to SEP, perception consists in sensory-based practices of interaction with objects, events, and states of affairs that are socially constituted. I oppose the representational view that perception is an indirect contact with the world, consists of the passive receiving and processing of sensory input, is in need of constant assessment of accuracy, and is a matter of individuals alone. I share the (...) basic enactivist insight that perception is a type of activity, but I depart from standard enactivism on the grounds of its individualistic bias and its limited conception of activity. Instead of motor actions, I formulate the concept of perceptual practices as the appropriate framework to understand perception. Perception is woven into socially informed, contextual, sensory-based everyday activities, such as food, dance, and dress, and even seemingly independent, basic perceptual activities and concepts are constituted by such practices. Perceptual individual interactions instantiate social perceptual practices but are not just repetitions of a script. We perceive objects in virtue of perspectives or appearances, not in spite of them, and on this basis I offer SEPâs take on experience, properties, and contents. I conceive perceptual experience as finely grained interactions between subjects and objects, both of which are spatially, temporally, and pragmatically situated. Objects and their sensory properties are perceived dynamically and always in multiple appearances. Perceptual content offers a pragmatic specification of the perceptual objects in the specific ways they appear to subjects. For SEP, perception is normatively structured. SEPâs perceptual normativity is not a worry about a supposed constant threat that our perceptions be nonveridical, but about the placement of perceptual things in a system of possibilities and expectations, cast in terms of degrees of fulfillment of expectations and in a horizon of pragmatic significance, both of which are functions of the socially constituted interactions between a perceiver and a rich theory of appearances. (shrink)

Amodal completion is the representation of those parts of the perceived object that we get no sensory stimulation from. While amodal completion is rife and plays an essential role in all sense modalities, philosophical discussions of this phenomenon have almost entirely been limited to vision. The aim of this paper is to examine in what sense we can talk about amodal completion in olfaction. We distinguish three different senses of amodal completion – (...) spatial, temporal and feature-based completion – and argue that all three are present and play a significant role in olfaction. (shrink)

The dual role of olfaction in both smelling and tasting, i.e. flavour perception, makes it an important test case for philosophical theories of sensory individuation. Indeed, the psychologist Paul Rozin claimed that olfaction is a “dual sense”, leading some scientists and philosophers to propose that we have not one, but two senses of smell: orthonasal and retronasal olfaction. In this paper I consider how best to understand Rozin’s claim, and upon what grounds one might judge there to (...) be one or two distinct olfactory modalities. I conclude that while Rozin may be right that humans have dual occurrences of an olfactory ‘sense’, the concept of a sense-modality, and hence the ‘sense’ of smell, is ambiguous between two different notions: a physiological sensory channel and an experiential modality, along the lines suggested by J. J. Gibson. Furthermore, recognising that these are complementary rather than competing conceptions of a sense-modality enables the formulation of a powerful ‘dual-concept’ framework for posing and addressing questions concerning the complex architecture of human multisensory experience. (shrink)

The empirical literature on phenomenal causality (the notion that causality can be perceived) is reviewed. Different potential types of phenomenal causality and variables that influence phenomenal causality were considered in Part I (Hubbard 2012b) of this two-part series. In Part II, broader questions regarding properties of phenomenal causality and connections of phenomenal causality to other perceptual or cognitive phenomena (different types of phenomenal causality, effects of spatial and temporal variance, phenomenal causality in infancy, effects of object properties, naïve (...) physics, spatial localization, other illusions, amodal completion, Gestalt principles of perceptual grouping, effects of context, differences between physical and social causality, effects of learning and experience, individual differences, effects of predictability, asymmetry in phenomenal causality, differences between perceived causality and perceived force, phenomenal causality in nonhuman animals) are considered. Potential mechanisms of phenomenal causality (inference from contiguity, a priori understanding, ampliation, perceptual learning, stimulus activity, beliefs regarding kinematics, haptic experience, beliefs regarding impetus, postdiction, innateness, modularity, specific neural structures) are also considered. (shrink)

Pain is commonly explained in terms of the perceptual activity of a distinct sensory modality, the function of which is to enable us to perceive actual or potential damage to the body. However, the characterization of pain experience in terms of a distinct sensory modality with such content is problematic. I argue that pain is better explained as occupying a different role in relation to perception: to indicate when the stimuli that are sensed in (...) perceiving anything by means of a sensory modality exceed a significant level of intensity. Viewing the system underlying pain experience as an integral and functionally integrated feature of all the senses provides a new perspective on the diverse forms of pain, what it is like to experience pain and the contrasting natures of pain and pleasure. (shrink)

Multisensory integration can alter information processing, and previous research has shown that such processes are modulated by sensory switch costs and prior experience. Here we report an incidental finding demonstrating, for the first time, the interplay between these processes and experimental factors, specifically the presence of the experimenter in the testing room. Experiment 1 demonstrates that multisensory motor facilitation in response to audiovisual stimuli is higher in those trials in which the sensory modality switches than (...) when it repeats. Those participants who completed the study while alone exhibited increased RT variability. Experiment 2 replicated these findings using the letters “b” and “d” presented as unisensory stimuli or congruent and incongruent multisensory stimuli. Multisensory enhancements were inflated following a sensory switch; that is, congruent and incongruent multisensory stimuli resulted in significant gains following a sensory switch in the monitored condition. However, when the participants were left alone, multisensory enhancements were only observed for repeating incongruent multisensory stimuli. These incidental findings therefore suggest that the effects of letter congruence and sensory switching on multisensory integration are partly modulated by the presence of an experimenter. (shrink)

This paper concerns epistemic developments in the field of sensory perception. I argue that Uexküll’s concept of the Umwelträume and certain principles of multisensory integration explain and describe in similar terms the manner in which different sensory modalities interact. Indeed, they both concern knowledge, describing in spatial terms how the mind makes itself up, makes up its objects, and how the objects, in turn, make up the mind. My intention is to set side by side these (...) two trends of thought in order to mutually explain them. I suggest that there is some sort of dialectic at work between the Umwelträume and multisensory integration: in the first case interaction between the senses results in the creation of high definition subjects, whereas in the latter the interaction of the senses results in high definition objects. (shrink)

Philosophers and cognitive scientists address the relationships among the senses and the connections between conscious experiences that form unified wholes. In this volume, cognitive scientists and philosophers examine two closely related aspects of mind and mental functioning: the relationships among the various senses and the links that connect different conscious experiences to form unified wholes. The contributors address a range of questions concerning how information from one sense influences the processing of information from the other senses and how unified (...) states of consciousness emerge from the bonds that tie conscious experiences together. Sensory Integration and the Unity of Consciousness is the first book to address both of these topics, integrating scientific and philosophical concerns. A flood of recent work in both philosophy and perception science has challenged traditional conceptions of the sensory systems as operating in isolation. Contributors to the volume consider the ways in which perceptual contact with the world is or may be “multisensory,” discussing such subjects as the modeling of multisensory integration and philosophical aspects of sensory modalities. Recent years have seen a similar surge of interest in unity of consciousness. Contributors explore a range of questions on this topic, including the nature of that unity, the degree to which conscious experiences are unified, and the relationship between unified consciousness and the self. Contributors Tim Bayne, David J. Bennett, Berit Brogaard, Barry Dainton, Ophelia Deroy, Frederique de Vignemont, Marc Ernst, Richard Held, Christopher S. Hill, Geoffrey Lee, Kristan Marlow, Farid Masrour, Jennifer Matey, Casey O'Callaghan, Cesare V. Parise, Kevin Rice, Elizabeth Schechter, Pawan Sinha, Julia Trommershaeuser, Loes C. J. van Dam, Jonathan Vogel, James Van Cleve, Robert Van Gulick, Jonas Wulff. (shrink)

We can perceive shapes visually and tactilely, and the information we gain about shapes through both sensory modalities is integrated smoothly into and functions in the same way in our behavior independently of whether we gain it by sight or touch. There seems to be no reason in principle we couldn't perceive shapes through other sensory modalities as well, although as a matter of fact we do not. While we can identify shapes through other sensory modalities—e.g., I (...) may know by smell (the scent of mango) that the object causing my sensory experience is round—this is not perceiving an object as shaped, but rather inferring from the character of one's sensory experience and collateral information that an object of a certain shape caused it. That it is possible to perceive shape by other modalities, however, is suggested by the case of bats and aquatic mammals like dolphins which navigate through their environment by a form of sonar. It is plausible that they have some form of auditory representation of space, and so of shape. These facts about shape perception raise important questions about the relation between those features of perceptual experience which are intrinsic to different sensory modalities and the nature of our perceptual representation of shapes, and, more generally, of the space within which we perceive shaped objects to be located. John Campbell's paper, "Molyneux's Problem" (see above), raises a number of interesting and important questions about the nature of our perception of shape properties, particularly the cross-modal nature of shape perception, and ties them to more general questions about the nature both of perceptual.. (shrink)

For more than a century now, researchers have acknowledged the existence of seemingly arbitrary crossmodal congruency effects between dimensions of sensory stimuli in the general population. Such phenomena, known by a variety of terms including 'crossmodal correspondences', involve individual stimulus properties, rely on a crossmodal mapping of unisensory features, and appear to be shared by the majority of individuals. In other words, members of the general population share underlying preferences for specific pairings across the senses. Crossmodal correspondences between (...) complementary sensory cues have often been referred to as synesthetic correspondences but, we would argue, differ from full-blown synesthetic experiences in a number of important ways, including the fact that there are no idiosyncratic concurrent sensations. Recent psychophysical evidence suggests that such crossmodal correspondences can modulate multisensory integration by helping to resolve the crossmodal binding problem. Here, we propose a model to account for the effects of crossmodal correspondences between complementary auditory and visual cues and critically review their relation to full-blown synesthesia. (shrink)

What is the metaphysical nature of perceptual experience? What evidence does experience provide us with? These questions are typically addressed in isolation. In order to make progress in answering both questions, perceptual experience needs to be studied in an integrated manner. I develop a unified account of the phenomenological and epistemological role of perceptual experience, by arguing that sensory states provide perceptual evidence due to their metaphysical structure. More specifically, I argue that sensory states (...) are individuated by the perceptual capacities employed and that there is an asymmetric dependence between their employment in perception and their employment in hallucination and illusion. Due to this asymmetric dependence, sensory states provide us with evidence. (shrink)

A central preoccupation of philosophy in the twentieth century was to determine constitutive conditions under which accurate (objective) empirical representation of the macrophysical environment is possible. A view that dominated attitudes on this project maintained that an individual cannot empirically represent a physical subject matter as having specific physical characteristics unless the individual can represent some constitutive conditions under which such representation is possible. The version of this view that dominated the century's second half maintained that objective empirical representation (...) of the physical environment requires the individual to be able to supplement this representation with representation of general constitutive features of objectivity. This essay criticizes instances of this version in P. F. Strawson and Quine. It maintains that all versions of the position postulate conditions on objective empirical representation that are more intellectual than are warranted. Such views leave it doubtful that animals and human infants perceptually represent elements in the physical environment. By appeal to common sense and to empirical perceptual psychology, this essay argues that unaided perception yields objective representation of the macrophysical environment. It does so in prelinguistic animals, even in animals that almost surely lack propositional attitudes. The essay concludes with explications of nondeflationary conceptions of representation and perception. It distinguishes nonperceptual sensing from perceptual representation and explicates perceptual representation as a type of objective sensory representation. Objectivity is marked by perceptual constancies. Representation is marked by a nontrivial role for veridicality conditions in explanations of the relevant states. (shrink)

Perceptual constancy, often defined as the perception of stable features under changing conditions, goes hand in hand with variation in how things look. A white wall in the orange afternoon sun still looks white, though its whiteness looks different compared with the same wall in the noon sun. Historically, this variation has often been explained in terms of our experience of “merely sensory” or subjective properties – an approach at odds with the fact that the variation does (...) track objective features of the perceptual situation, such as illumination. One approach, becoming more common, is to account for the variation in terms of further “dimensions” to perceptual experience. Especially in colour perception, this is a natural thought to have but the idea is often left vague. In this paper I argue that the “dimensional” strategy has problems of its own, but is useful in drawing out some interesting complications in the way perceptual experience is structured. Specifically, the structure of “constancy spaces” brings out the different ways in which there is stability and instability in the experience of constancy, without the need for novel or merely subjective features. Instability arises in a contingent structural feature of perceptual experience. (shrink)

The first part of this survey article presented a cartography of some of the more extensively studied forms of multisensory processing. In this second part, I turn to examining some of the different possible ways in which the structure of conscious perceptual experience might also be characterized as multisensory. In addition, I discuss the significance of research on multisensory processing and multisensory consciousness for philosophical debates concerning the modularity of perception, cognitive penetration, and the (...) individuation of the senses. (shrink)

Philosophers of perception widely agree that sensory properties, like color, are represented in perceptual experience. Arguments are usually needed to establish that something other than sensory properties, for example three-dimensional objects or kind properties, are part of perceptual content. Call the idea that sensory properties are represented in perceptual experience the Sensation View (SV). Given its widespread acceptance, we may expect to find strong reasons for holding SV. In this paper, I argue that (...) we lack such reasons: SV is largely unjustified. We have surprisingly poor justification for thinking that sensory properties are represented in perception. By focusing on the case of vision, I show that an embedded understanding of visual perception, and empirical evidence in cognitive psychology, indicate that SV is far from warranted. (shrink)

Perception is the ultimate source of our knowledge about contingent facts. It is an extremely important philosophical development that starting in the last quarter of the twentieth century, philosophers have begun to change how they think of perception. The traditional view of perception focussed on sensory receptors; it has become clear, however, that perceptual systems radically transform the output of these receptors, yielding content concerning objects and events in the external world. Adequate understanding of this (...) process requires that we think of perception in new ways—how it operates, the differences among the modalities, and integration of content provided by the individual senses. Philosophers have developed new analytic tools, and opened themselves up to new ways of thinking about the relationship of perception to knowledge. The Oxford Handbook of the Philosophy of Perception is a collection of entries by leading researchers that reviews these new directions in philosophical thought. The Introduction to the Handbook reviews the history of the subject from its beginnings in ancient Greece to the nineteenth century, and the way that science and philosophy have together produced new conceptions during the last hundred years. It shows how the new thinking about perception has led to a complex web of theories. (shrink)

When a user integrates a sensory substitution device into her life, the process involves perceptual learning, that is, ‘relatively long-lasting changes to an organism’s perceptual system that improve its ability to respond to its environment’ (Goldstone 1998: 585). In this paper, I explore ways in which the extensive literature on perceptual learning can be applied to help improve sensory substitution devices. I then use these findings to answer a philosophical question. Much of the philosophical debate (...) surrounding sensory substitution devices concerns what happens after perceptual learning occurs. In particular, should the resultant perceptual experience be classified in the substituted modality (as vision), in the substituting modality (as auditory or tactile), or in a new sense modality? I propose a novel empirical test to help resolve this philosophical debate. (shrink)

How do people learn multisensory, or amodal, representations, and what consequences do these representations have for perceptual performance? We address this question by performing a rational analysis of the problem of learning multisensory representations. This analysis makes use of a Bayesian nonparametric model that acquires latent multisensory features that optimally explain the unisensory features arising in individual sensory modalities. The model qualitatively accounts for several important aspects of multisensory perception: (a) it integrates (...) information from multiple sensory sources in such a way that it leads to superior performances in, for example, categorization tasks; (b) its performances suggest that multisensory training leads to better learning than unisensory training, even when testing is conducted in unisensory conditions; (c) its multisensory representations are modality invariant; and (d) it predicts ‘‘missing” sensory representations in modalities when the input to those modalities is absent. Our rational analysis indicates that all of these aspects emerge as part of the optimal solution to the problem of learning to represent complex multisensory environments. (shrink)

Whatever the answer to Molyneux's question is, it is certainly not obvious that the answer is ‘yes’. In contrast, it seems clear that we should answer affirmatively a temporal variation on Molyneux's question, introduced by Gareth Evans. I offer a phenomenological explanation of this asymmetry in our responses to the two questions. This explanation appeals to the modality‐specific spatial structure of perceptual experience and its amodal temporal structure. On this explanation, there are differences in the (...) class='Hi'>perception of spatial properties in different modalities, but these differences do not stand in the way of the objectivity of perceptual experience. (shrink)

Our different senses put us in contact with the same world. In this paper, I use unusual objects and situations to bring out structural dissimilarities in the way our senses relate to the same world of material objects. In the first part, I briefly discuss the perceptual presence of spatial and material things. Using uncommon objects allows me to treat this issue without any need to invoke what it is like to have visual experiences. What comes to the fore (...) in these analyses, however, seems less obvious in experiences of the other senses. Therefore, in the second part, I propose a strategy, invoking unusual situations, to weed out the multisensory associations that enrich our normal relation to objects, in order to get a better grip on the perceptual correlate of the different senses. Although the actual correlates of the senses may not be material objects in each case, I explain why they are nonetheless occurrences in a spatial and material world. (shrink)

Philosophers and scientists have studied sensory perception and, in particular, vision for many years. Increasingly, however, they have become interested in the nonvisual senses in greater detail and the problem of individuating the senses in a more general way. The Aristotelian view is that there are only five external senses—smell, taste, hearing, touch, and vision. This has, by many counts, been extended to include internal senses, such as balance, proprioception, and kinesthesis; pain; and potentially other human and nonhuman (...) senses. This “multisensory turn” has been driven partly by developments in contemporary psychology and neuroscience, which have revealed a host of complex interrelations and interactions between sensory modalities previously thought to be distinct. Contrasts between modalities and other crossmodal phenomena, including multisensory integration, synesthesia, and sensory substitution, have also begun to receive more attention in a burgeoning scientific and philosophical literature on multisensory perception and other crossmodal effects. This article focuses on recent empirically informed contributions to the philosophy of perception, as well as key scientific works that provide important background information and insights into the nature of the senses and sensory perception. Indeed, one of the lessons of the multisensory turn, and of contemporary philosophy of mind more generally, is that philosophers ignore this body of empirical research at their peril because many human and animal senses turn out to be richer and more complex than philosophers and scientists had previously imagined, making this a fruitful area for interdisciplinary interaction and research. (shrink)

This is the editors' Introduction to a special issue of the journal, Multisensory Research. European philosophers of the modern period found multisensory perception to be impossible because they thought that perceptual ideas are defined by how they are experienced. Under this conception, the individual modalities are determinables of ideas—just as colour is a determinable that embraces red and blue, so also the visual is a determinable that embraces colour and (visually experienced) shape. Since no idea is (...) experienced as, for example, both visual and auditory, there can be no such thing as audiovisual perception. This conception of modality is not directly contested, but a variety of perceptual phenomena are listed that could raise interesting questions if treated as multimodal in origin. (shrink)

Haptic touch is an inherently active and exploratory form of perception, involving both coordinated movements and an array of distinct sensory receptors in the skin. For this reason, some have claimed that haptic touch is not a single sense, but rather a multisensory collection of distinct sensory systems. Though this claim is often made, it relies on what I regard as a confused conception of multisensory interaction. In its place, I develop a nuanced hierarchy (...) of multisensory involvement. According to this hierarchy, touch turns out to be a single modality in that its various receptors assign their features to the same tangible objects. When we grasp an object a range of distinct properties?shape, warmth, heft, texture, etc.?are all felt to belong to the object, just as different visual properties are associated with a visual object. Paradigm multisensory experiences, on the other hand, involve associations between distinct perceptual experiences, as when the way something looks affects the way something sounds. Thus despite its functional and physiological diversity, haptic touch can be regarded as a single sense. (shrink)

Objective: Evidence suggests people experience an oral size illusion and commonly perceive oral size inaccurately; however, the nature of the illusion remains unclear. The objectives of the present study were to confirm the presence of an oral size illusion, determine the magnitude (amount) and direction (underestimation or overestimation) of the illusion, and determine whether immediately prior crossmodal perceptual experiences affected the magnitude and direction. Design: Participants (N = 27) orally assessed 9 sizes of stainless steel spheres (1/16 in to (...) 1/2 in) categorized as small, medium, or big, and matched them with digital and visual reference sets. Each participant completed 20 matching tasks in 3 assessments. For control assessments, 6 oral spheres were matched with reference sets of same-sized spheres. For primer-control assessments, similar to control, 6 matching tasks were preceded by cross-modal experiences of the same-sized sphere. For experimental assessments, 8 matching tasks were preceded by a cross-modal experience of a differently sized sphere. Results: For control assessments, small and medium spheres were consistently underestimated, and big spheres were consistently overestimated. For experimental assessments, magnitude and direction of the oral size illusion varied according to the size of the sphere used in the cross-modal experience. Conclusion: Results seemed to confirm an oral size illusion, but direction of the illusion depended on the size of the object. Immediately prior cross-modal experiences influenced magnitude and direction of the illusion, suggesting that aspects of oral perceptual experience are dependent upon factors outside of oral perceptual anatomy and the properties of the oral stimulus. (shrink)

Cognitive scientists have long known that the modalities interact during perceptual processing. Cross-modal illusions like the ventriloquism effect show that the course of processing in one modality can alter the course of processing in another. But how do the modalities interact in the specific domain of object perception? This paper distinguishes and analyzes two kinds of multisensory interaction in object perception. First, the modalities may bind features to a single object or (...) event. Second, the modalities may cooperate when differentiating an object or event from its surroundings. I critically evaluate evidence for various forms of multisensory binding. I then consider the case for multisensory differentiation. I argue that existing evidence for multisensory differentiation is inconclusive. I highlight ways that the issue might be empirically resolved. (shrink)

Suppose that you are at a live jazz show. The drummer begins a solo. You see the cymbal jolt and you hear the clang. But in addition seeing the cymbal jolt and hearing the clang, you are also aware that the jolt and the clang are part of the same event. Casey O’Callaghan (forthcoming) calls this awareness “intermodal feature binding awareness.” Psychologists have long assumed that multimodal perceptions such as this one are the result of a subpersonal feature binding mechanism (...) (see Vatakis and Spence, 2007, Kubovy and Schutz, 2010, Pourtois et al., 2000, and Navarra et al., 2012). I present new evidence against this. I argue that there is no automatic feature binding mechanism that couples features like the jolt and the clang together. Instead, when you experience the jolt and the clang as part of the same event, this is the result of an associative learning process. The cymbal’s jolt and the clang are best understood as a single learned perceptual unit, rather than as automatically bound. I outline the specific learning process in perception called “unitization,” whereby we come to “chunk” the world into multimodal units. Unitization has never before been applied to multimodal cases. Yet I argue that this learning process can do the same work that intermodal binding would do, and that this issue has important philosophical implications. Specifically, whether we take multimodal cases to involve a binding mechanism or an associative process will have impact on philosophical issues from Molyneux’s question to the question of how active or passive we consider perception to be. (shrink)

This paper presents an account of the senses and what differentiates them that is compatible with richly multisensory perception and consciousness. According to this proposal, senses are ways of perceiving. Each sense is a subfaculty that comprises a collection of perceptual capacities. What each sense shares and what differentiates one sense from another is the manner in which those capacities are exercised. Each way of perceiving involves a distinct type of information gathering, individuated by (...) the information it functions to extract and the medium from which it does so. This approach distinguishes the project of characterizing and differentiating senses from that of attributing experiences to sensory modalities. Perceptual experiences are episodes in which perceptual capacities are exer- cised. Conscious perceptual episodes may be ascribed to distinct sensory modalities, according to the manners in which perceptual capacities are deployed on an occasion. According to this account, senses are not exclusive. First, their capacities may overlap. Second, perceptual episodes, including conscious experiences, may belong to multiple senses. Indeed, some episodes require the joint use of several senses. In this account, subjects have only limited first-person knowledge of the senses they employ. (shrink)

It is through touch that we are able to interact directly with the world; it is our primary conduit of both pleasure and pain. Touch may be our most immediate and powerful sense—“the first sense" because of the central role it plays in experience. In this book, Matthew Fulkerson proposes that human touch, despite its functional diversity, is a single, unified sensory modality. Fulkerson offers a philosophical account of touch, reflecting the interests, methods, and approach that (...) define contemporary philosophy; but his argument is informed throughout by the insights and constraints of empirical work on touch. Human touch is a multidimensional object of investigation, Fulkerson writes, best served by using a variety of methods and approaches. -/- To defend his view of the unity of touch, Fulkerson describes and argues for a novel, unifying role for exploratory action in touch. He goes on to fill in the details of this unified, exploratory form of perception, offering philosophical accounts of tool use and distal touch, the representational structure of tangible properties, the spatial content of touch, and the role of pleasure in tactual experience. -/- Fulkerson’s argument for the unique role played by exploratory action departs notably from traditional vision-centric philosophical approaches to perception, challenging the received view that action plays the same role in all sensory modalities. The robust philosophical account of touch he offers in The First Sense has significant implications for our general understanding of perception and perceptual experience. (shrink)

How many senses do humans possess? Five external senses, as most cultures have it—sight, hearing, touch, smell, and taste? Should proprioception, kinaesthesia, thirst, and pain be included, under the rubric bodily sense? What about the perception of time and the sense of number? Such questions reduce to two. 1. How do we distinguish a sense from other sorts of information-receiving faculties? 2. By what principle do we distinguish the senses? Aristotle discussed these questions in the De (...) Anima. H. P. Grice revived them in 1967. More recently, they have taken on fresh interest as a result of a collection of essays edited by Fiona Macpherson. This entry reviews some approaches to these questions and advances some new ideas for the reader’s consideration. It proposes that the senses constitute an integrated learning system, membership in which answers question 1. It also proposes that the modalities can be distinguished from one another in two ways, by the means of information pick-up and by the kinds of activity that a perceiver undertakes to make use of them. (shrink)