Pessoa et al. (1998a) summarize a wide body of data suggesting that perceptual filling-in phenomena can be attributed to neural filling-in processes. However, they reject, on philosophical grounds, the hypothesis that filled-in representations in the brain are the immediate substrate of visual percepts. It is proposed in this commentary that resonant binding between distributed cortical areas may instead be the crucial ingredient for conscious visual percepts, and that filling-in processes may facilitate the interactions between behaving organisms (...) and object surfaces. These suggestions circumvent some of the philosophical problems associated with the idea of localized visual representations. (shrink)

In visual science the term filling-inis used in different ways, which often leads to confusion. This target article presents a taxonomy of perceptual completion phenomena to organize and clarify theoretical and empirical discussion. Examples of boundary completion (illusory contours) and featural completion (color, brightness, motion, texture, and depth) are examined, and single-cell studies relevant to filling-in are reviewed and assessed. Filling-in issues must be understood in relation to theoretical issues about neuralignoring an absencejumping to a conclusionanalytic (...) isomorphismCartesian materialism, a particular neural stage that forms the immediate substrate of perceptual experience enactiveanimatesubpersonal” considerations about internal processing, but rather by considerations about the task of vision at the level of the animal or person interacting with the world. (shrink)

Filled-in sensations exhibit a distinctive mélange of causal features, resembling perceptual sensations in some respects and imagery in others. This commentary identifies several of these shared causal features and advances the hypothesis that filled-in sensations may constitute the primordial species of imagery, the evolutionary neurofunctional precursor of paradigmatic forms of imagery.

“Finding out” about the visual world as approached from the organismic level may well include the “filling-in” type of perceptual completion if considered in terms of underlying neurophysiological mechanisms. But “filling in” can be interpreted not only as a result of within-level propagating of neural activity, but as a byproduct of the process that is necessary for modulating preconscious information about physically present objects or events so as to generate conscious quality in attending to them.

Boundary completion and surface filling-in are computationally complementary processes whose multiple processing stages form processing streams that realize a hierarchical resolution of uncertainty. Such complementarity and uncertainty principles provide a new foundation for philosophical discussions about visual perception, and lead to neural explanations of difficult perceptual data.

The following points are discussed in response to the commentaries: (1) A taxonomy of perceptual completion phenomena should rely on both phenomenological and mechanistic criteria. (2) Certain forms of perceptual completion are caused by topographically organized neural processes the view that there must be a pictorial or spatial neural-perceptual isomorphism at the bridge locus – should be rejected. Although more abstract kinds of isomorphism are central to the neural-perceptual mapping, the perceptual cannot be exhaustively explained (...) in terms of the neural, and therefore the explanation of perception cannot be reduced to uncovering neural-perceptual isomorphisms. (5) The task of vision is to guide action in the world, not to construct a detailed world-model in the head. (6) Neural filling-in facilitates the integration of information and thereby helps the animal find out about its environment. (7) Perceptual content needs to be understood at the level of the person or animal interacting in the world. (shrink)

(1) The main issue with regard to modal and amodal completion is not which phenomena are cognitive, and which perceptual. At the level of the animal, both are visuo-cognitive. At the level of visual processing, however, we need to dissect the different functional effects of these kinds of completion. (2) Resonant binding between distributed cortical areas may play a role in perceptual completion, but evidence is needed.

Perceptual filling-in for vision is the insertion of visual properties (e.g., color, contour, luminance, or motion) into one’s visual field, when those properties have no corresponding retinal input. This paper introduces and provides preliminary empirical support for filled/non-filled pairs, pairs of images that appear identical, yet differ by amount of filling-in. It is argued that such image pairs are important to the experimental testing of theories of consciousness. We review recent experimental research and conclude that filling-in (...) involves brain activity with relatively high integrated information (Phi) compared to veridical visual perceptions. We then present filled/non-filled pairs as an empirical challenge to the integrated information theory of consciousness, which predicts that phenomenologically identical experiences depend on brain processes with identical Phi. (shrink)

This informative and conceptually stimulating target article is very useful. I merely query whether the term “illusory contours” is appropriate for gap filling; “illusory surfaces” seems better – and “fictional surfaces” better still. These seem to be rule based rather than knowledge based, suggesting indeed the importance of distinguishing rules (analogous to syntax in language) from knowledge (equivalent to semantics) for classifying perceptual phenomena.

The Emergic Cognitive Model (ECM) is a unified computational model of visual filling-in based on the Emergic Network architecture. The Emergic Network was designed to help realize systems undergoing continuous change. In this thesis, eight different filling-in phenomena are demonstrated under a regime of continuous eye movement (and under static eye conditions as well). -/- ECM indirectly demonstrates the power of unification inherent with Emergic Networks when cognition is decomposed according to finer-grained functions supporting change. These can interact (...) to raise additional emergent behaviours via cognitive re-use, hence the Emergic prefix throughout. Nevertheless, the model is robust and parameter free. Differential re-use occurs in the nature of model interaction with a particular testing paradigm. -/- ECM has a novel decomposition due to the requirements of handling motion and of supporting unified modelling via finer functional grains. The breadth of phenomenal behaviour covered is largely to lend credence to our novel decomposition. -/- The Emergic Network architecture is a hybrid between classical connectionism and classical computationalism that facilitates the construction of unified cognitive models. It helps cutting up of functionalism into finer-grains distributed over space (by harnessing massive recurrence) and over time (by harnessing continuous change), yet simplifies by using standard computer code to focus on the interaction of information flows. Thus while the structure of the network looks neurocentric, the dynamics are best understood in flowcentric terms. Surprisingly, dynamic system analysis (as usually understood) is not involved. An Emergic Network is engineered much like straightforward software or hardware systems that deal with continuously varying inputs. Ultimately, this thesis addresses the problem of reduction and induction over complex systems, and the Emergic Network architecture is merely a tool to assist in this epistemic endeavour. -/- ECM is strictly a sensory model and apart from perception, yet it is informed by phenomenology. It addresses the attribution problem of how much of a phenomenon is best explained at a sensory level of analysis, rather than at a perceptual one. As the causal information flows are stable under eye movement, we hypothesize that they are the locus of consciousness, howsoever it is ultimately realized. (shrink)

Comparisons between modally and amodally completed regions show that perceptual filling-in is not merely the ignoring of absences. Illusory filled-in colour arises for modal completion, but not for amodal completion in comparable displays. We find that attention spreads automatically to modally but not amodally completed regions from their inducers, revealing a functional effect of filled-in colour.

This commentary sides with Pessoa and his colleagues in arguing that some types of perceptual filling-in are linked with a spread of cortical activity, a hypothesis that has often been rejected on philosophical grounds. Some recent data are discussed that strengthen this linking hypothesis and indicate that a spread of cortical activity may be essential for normal surface perception.

The physiological blind spot corresponds to the optic disc where the retina contains no light-detecting photoreceptor cells. Our perception seemingly fills in this gap in input. Here we suggest that rather than an active process, such perceptual filling-in could instead be a consequence of the integration of visual inputs at higher stages of processing discounting the local absence of retinal input. Using functional brain imaging, we resolved the retinotopic representation of the physiological blind spot in early human visual (...) cortex and measured responses while participants perceived filling-in. Responses in early visual areas simply reflected the absence of visual input. In contrast, higher extrastriate regions responded more to stimuli in the eye containing the blind spot than the fellow eye. However, this signature was independent of filling-in. We argue that these findings agree with philosophical accounts that posit that the concept of filling-in of absent retinal input is unnecessary. (shrink)

Perceptual Confidence is the view that perceptual experiences assign degrees of confidence. After introducing, clarifying, and motivating Perceptual Confidence, I catalogue some of its more interesting consequences, such as the way it blurs the distinction between veridical and illusory experiences, a distinction that is sometimes said to carry a lot of metaphysical weight. I also explain how Perceptual Confidence fills a hole in our best scientific theories of perception and why it implies that experiences don't have (...) objective accuracy conditions. (shrink)

Perceptual completion fills the gap for discrete perception to become continuous. Similarly, dynamic perceptual completion provides an experience of dynamic continuity. Our recent discovery of the ‘happening’ element of DPC completes the total experience for dynamism in the flow of time. However, a phenomenological explanation for these experiences is essential. The Snapshot Hypotheses especially the Dynamic Snapshot View provides the most comprehensive explanation. From that understanding the ‘two times’ problem can be addressed. The static time of spacetime cosmologies (...) has been irreconcilable with the dynamic FOT. Dismissing the FOT as an illusion is unsatisfactory. Therefore, we provide four hypotheses for the TTP.1) Since cosmological static time demands that all events are discrete, DPC elements for dynamism should likewise be expected to be discrete and accounted for by a snapshot phenomenology such as the DSV. 2) If temporality can be demonstrated to be similar to apparent motion by being a snapshot phenomenon and not demanding temporal extension it would confirm the DSV and permit reconciliation with static time. 3) If the ‘present moment’ is subjective as static time theories suggest, it should be possible experimentally for an observer to choose his own ‘present’ by moving to various points in the past with the aid of virtual reality. 4) If dynamism e.g. motion can be precluded without significant information loss or violating physics principles it is a cognitive add-on, thereby contradicting non-static time theories which suggest that time is ‘real.’ We confirm those hypotheses. (shrink)

Perceptual organization comprises a wide range of processes such as perceptual grouping, figure-ground organization, filling-in, completion, and perceptual switching. The Oxford Handbook of Perceptual Organization provides a broad and extensive review of the current literature, written in an accessible form for scholars and students.

Although current debates in epistemology and philosophy of mind show a renewed interest in perceptual illusions, there is no systematic work in the philosophy of perception and in the psychology of perception with respect to the concept of illusion and the relation between illusion and error. This book aims to fill that gap.

The filling-in process proposed as a cover up for the existence of the blind spot has some conceptual similarities to blindsight. The perceptual operation of a hypothetical mechanism responsible for filling in represents a logical paradox. The apparent indeterminacy of the percept in the optic-disc region can be tested experimentally by viewing the grating test pattern below.

We present select examples of how visual phenomena can serve as tools to uncoverbrain mechanisms. Specifically, receptive field organization is proposed as a Gestalt-like neural mechanism of perceptual organization. Appropriate phenomena, such as brightness and orientation contrast, subjective contours, filling-in, and aperture-viewed motion, allow for a quantitative comparison between receptive fields and their psychophysical counterparts, perceptive fields. Phenomenology might thus be extended from the study of perceptual qualities to their transphenomenal substrates, including memory functions. In conclusion, classic (...) issues of Gestalt psychology can now be related to modern. (shrink)

Following the pioneering studies of the receptive field (RF), the concept gained further significance for visual perception by the discovery of input effects from beyond the classical RF. These studies demonstrated that neuronal responses could be modulated by stimuli outside their RFs, consistent with the perception of induced brightness, color, orientation, and motion. Lesion scotomata are similarly modulated perceptually from the surround by RFs that have migrated from the interior to the outer edge of the scotoma and in this way (...) provide filling-in of the void. Large RFs are advantageous to this task. In higher visual areas, such as the middle temporal and inferotemporal lobe, RFs increase in size and lose most of their retinotopic organization while encoding increasingly complex features. Whereas lowerlevel RFs mediate perceptual filling-in, contour integration, and figure–ground segregation, RFs at higher levels serve the perception of grouping by common fate, biological motion, and other biologically relevant stimuli, such as faces. Studies in alert monkeys while freely viewing natural scenes showed that classical and nonclassical RFs cooperate in forming representations of the visual world. Today, our understanding of the mechanisms underlying the RF is undergoing a quantum leap. What had started out as a hierarchical feedforward concept for simple stimuli, such as spots, lines, and bars, now refers to mechanisms involving ascending, descending, and lateral signal flow. By extension of the bottom-up paradigm, RFs are nowadays understood as adaptive processors, enabling the predictive coding of complex scenes. Top-down effects guiding attention and tuned to task-relevant information complement the bottom-up analysis. (shrink)

Defenders of The Pure View – “Purists”, as I shall call them – maintain that perception is pure presentation. That is, a perceptual experience has no commitments that exceed what is given or presented in the experience. I argue The Pure View seems unable to offer a convincing account of amodal completion. I distinguish three Purist strategies for addressing amodal completion, and suggest that none is very promising.

In psychophysical experiments, the use of a psychophysical procedure of brightness/darkness cancellation shed light on interactions between spatial arrangement and figure–ground contrast in the perceptual filling in of achromatic and colored surfaces.Achromatic and chromatic Kanizsa squares with varying contrast, contrast polarity, and inducer spacingwere used to test how these factors interact in the perceptual filling in of surface brightness or darkness. The results suggest that the neuronal processing of surfaces with apparent contrast, leading to figure–ground segregation (...) (i.e., perceptual organization), is governed by mechanisms that integrate both luminance contrast and spatial information carried by the inducing stimuli, while discarding information on contrast polarity or color. The findings are discussed in relation to earlier observations on brightness assimilation and contrast. They support theories of nonantagonistic neural mechanisms suppressing local contrast or color signs in brightnessbased figure–ground percepts. Such mechanismsmight be necessary to cancel potentially conflicting polarities in geometricallycomplex visual stimuli so that perceptual filling in resulting in the most plausible representation of figure and ground can be achieved. (shrink)

Implicit and explicit filling-in phenomena should be distinguished. Blind spot phenomena and mechanisms of boundary completion can be accounted for by implicit filling-in. Surface regions are “painted” with perceptual quantities, such as brightness, by explicit filling-in. “Filling-in” and “finding-out” relate to different computational tasks. Mechanisms of purposive computation (e.g., for navigation) evaluate local measurements, thus “finding out”; whereas mechanisms for grasping might require passive reconstruction, thus “filling in.”.

This book offers solutions to two persistent and I believe closely related problems in epistemology. The first problem is that of drawing a principled distinction between perception and inference: what is the difference between seeing that something is the case and merely believing it on the basis of what we do see? The second problem is that of specifying which beliefs are epistemologically basic (i.e., directly, or noninferentially, justified) and which are not. I argue that what makes a belief a (...) perceptual belief, or a basic belief, is not any introspectible feature of the belief but rather the nature of the cognitive system, or "module", that is causally responsible for the belief. Thus, even zombies, who in the philosophical literature lack conscious experiences altogether, can have basic, justified, perceptual beliefs. -/- The theories of perceptual and basic beliefs developed in the monograph are embedded in a larger reliabilist epistemology. I use this theory of basic beliefs to develop a detailed reliabilist theory: Inferentialist Reliabilism, which offers a reliabilist theory of inferential justification and which solves some longstanding problems for other reliabilist views by demanding inferential support for some—but not all—beliefs. The book is an instance of a thoroughgoingly naturalistic approach to epistemology. Many of my arguments have an empirical basis, and the view that I endorse reserves a central role for the cognitive sciences—in particular, cognitive neuroscience—in filling in the details of an applied epistemological theory. (shrink)

The thresholds of human observers detecting line targets improve significantly when the targets are presented in a spatial context of collinear inducing stimuli. This phenomenon is referred to as spatial facilitation, and may reflect the output of long-range interactions between cortical feature detectors. Spatial facilitation has thus far been observed with luminance-defined, achromatic stimuli on achromatic backgrounds. This study compares spatial facilitation with line targets and collinear, edge-like inducers defined by luminance contrast to spatial facilitation with targets and inducers defined (...) by color contrast. The results of a first experiment show that achromatic inducers facilitate the detection of achromatic targets on gray and colored backgrounds, but tend to suppress the detection of chromatic targets. Chromatic inducers facilitate the detection of chromatic targets on gray and colored backgrounds, but tend to suppress the detection of achromatic targets. Chromatic spatial facilitation appears to be strongest when inducers and background are isoluminant. The results of a second experiment show that spatial facilitation with chromatic targets and inducers requires a longer exposure duration of the inducers than spatial facilitation with achromatic targets and inducers, which is already fully effective at an inducer exposure of 30 ms only. The findings point towards two separate mechanisms for spatial facilitation with collinear form stimuli: one that operates in the domain of luminance, and one that operates in the domain of color contrast. These results are consistent with neural models of boundary and surface formation which suggest that achromatic and chromatic visual cues are represented on different cortical surface representations that are capable of selectively attracting attention. Multiple copies of these achromatic and chromatic surface representations exist corresponding to different ranges of perceived depth from an observer, and each can attract attention to itself. Color and contrast differences between inducing and test stimuli, and transient responses to inducing stimuli, can cause attention to shift across these surface representations in ways that sometimes enhance and sometimes interfere with target detection. (shrink)

© The Authors 2017. Published by Oxford University Press on behalf of The Analysis Trust. All rights reserved. For Permissions, please email: [email protected] Colour is a welcome work in history and philosophy of science.1 The opening chapters offer a fresh take on the history of perceptual theory and a broad overview of contemporary philosophy of colour. This is followed by the central fourth chapter, which introduces readers to a cluster of empirical data that to this point have not received (...) explicit treatment in philosophy. The core message is that instead of thinking of colour vision as filling in or painting the experienced world of primary qualities, we should think of colour vision as helping us to experience primary qualities. The colour visual system does not colour in an experiential world of primary qualities, it uses colour for the experience of those qualities. This colouring... (shrink)

This monograph presents new material on Francisco Suárez’s comprehensive theory of sense perception. The core theme is perceptual intentionality in Suárez’s theory of the senses, external and internal, as presented in his Commentaria una cum quaestionibus in libros Aristotelis De anima published in 1621. The author targets the question of the multistage genesis of perceptual acts by considering the ontological “items” involved in the procession of sensory information. However, the structural issue is not left aside, and the nature (...) of the relationship due to which our perceptions are mental representations of this or that object is also considered. The heuristic historiographical background includes not only the theories of classical authors, such as Aristotle and Aquinas, but also those of late medieval authors of the fourteenth century. These are headed by John Duns Scotus, John of Jandun, Peter Auriol and Peter John Olivi. Readers will discover the differences between Suárez’s and Aquinas’s views, as well as other sources that may have served as positive inspiration for the Jesuit’s theory. By considering the late medieval philosophy of the fourteenth century, this book helps, to a certain extent, to fill a gap in the historiography of philosophy regarding the link between late medieval and early modern scholasticism. In the first part of the book, the metaphysics of the soul and powers is considered. Chapters on the external senses follow, covering topics such as the sensible species, the causes of sensation, self-awareness, and the ordering of the external senses. A further chapter is devoted to the internal senses and the author argues that by reducing the number and functional scope of the interior senses Suárez deepens the gap between the external senses and the intellect, but he reduces it through emphasizing the unifying efficacy of the soul.This book brings a synthetic and unifying perspective to contemporary research and will particularly appeal to graduate students and researchers in theology and philosophy, especially philosophy of mind. (shrink)

In this paper I outline an account of the structure of perceptual justification that develops Wittgenstein’s thought that the possibility of acquiring any degree of justification for our beliefs depends on placing certain propositions outside the route of empirical inquiry, turning them into the ‘hinges’ of our rational evaluations. The proposal is akin to ‘moderate’ accounts of the structure of perceptual justification, but it conjoins Wittgenstein’s insight with explanationist and contrastivist ideas, and so differs in important respects both (...) from such accounts and from other versions of hinge epistemology. I maintain that the basic presuppositions of the epistemic practice of taking experience at face value are not totally refractory to evidential assessment, arguing that they can receive some degree of second-order empirical justification via inference to the best explanation. And I address the worry that the account may face the problem of ‘easy knowledge’ by helping myself to the contrastivist view that empirical knowledge is best understood as a three-place, contrastive relation between an agent, a proposition (or fact) and a contrast. This leads me to replace the usual closure principles for epistemic justification and knowledge with corresponding contrastive principles, filling in the final details of contrastive hinge epistemology. (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)

Perceptual neuroscience has identified mechanisms of perceptual grouping which account for the ways in which visual sensitivity to ordered structure and regularities expresses itself, in behavior and in the brain. The need to actively construct order, notably representations of objects in depth, is mandated as soon as visual signals reach the retina, given the occlusion of retinal signals by retinal veins and other retinal elements or blur. Multiple stages of neural processing transform fragmented signals into visual key representations (...) of 3D scenes that can be used to control effective behaviors. Since our survival depends on our ability to pick up order in the physical world, and since we conceive the physical world as an ordered one, our perception must somehow be sensitive to order. The articles from this collection illustrate how texture dissimilarity, boundary completion, surface filling-in, and figure-ground segregation generate perceptual order. (shrink)

Perceptual experience is often said to be transparent; that is, when we have a perceptual experience we seem to be aware of properties of the objects around us, and never seem to be aware of properties of the experience itself. This is a introspective fact. It is also often said that we can infer a metaphysical fact from this introspective fact, e.g. a fact about the nature of perceptual experience. A transparency theory fills in the details for (...) these two facts, and bridges the gap between them. We have three aims: to scrutinize Michael Tye’s transparency theory :137–151, 2002; Consciousness revisited: materialism without phenomenal concepts, MIT Press, Cambridge, 2009; Philos Stud 170:39–57, 2014a), introduce a new transparency theory, and advance a meta-theoretical hypothesis about the interest, and import, of transparency theories. (shrink)

When viewing a circular coin rotated in depth, it fills an elliptical region of the distal scene. For some, this appears to generate a two-fold experience, in which one sees the coin as simultaneously circular (in light of its 3D shape) and elliptical (in light of its 2D ‘perspectival shape’ or ‘p-shape’). An energetic philosophical debate asks whether the latter p-shapes are genuinely presented in perceptual experience (as ‘perspectivalists’ argue) or if, instead, this appearance is somehow derived or inferred (...) from experience (as ‘anti-perspectivalists’ argue). This debate, however, has largely turned on introspection. In a recent study, Morales, Bax, and Firestone (2020) aim to provide the first empirical test of this question. They asked subjects to find an elliptical coin seen face-on from a search array that also included a circular coin seen either face-on or at an angle. They found that subjects reacted more slowly when the distracting circle was seen at an angle, such that it’s p-shape matched that of the target ellipse. From this, they concluded that the similar p-shape between the ellipse and circle constituted a phenomenal similarity between the two, and thus that perspectivalism is true. We show that these results can also be explained by pre-attentive guidance by unconscious representations (in what follows, just “unconscious pre-attentive guidance”) and that this explanation is at least as plausible as one from phenomenal similarity. Thus, we conclude that the experiment does not support perspectivalism over anti-perspectivalism. (shrink)

This paper addresses a number of closely related questions concerning Kant's model of intentionality, and his conceptions of unity and of magnitude [Gröβe]. These questions are important because they shed light on three issues which are central to the Critical system, and which connect directly to the recent analytic literature on perception: the issues are conceptualism, the status of the imagination, and perceptual atomism. In Section 1, I provide a sketch of the exegetical and philosophical problems raised by Kant's (...) views on these issues. I then develop, in Section 2, a detailed analysis of Kant's theory of perception as elaborated in both the Critique of Pure Reason and the Critique of Judgment; I show how this analysis provides a preliminary framework for resolving the difficulties raised in Section 1. In Section 3, I extend my analysis of Kant's position by considering a specific test case: the Axioms of Intuition. I contend that one way to make sense of Kant's argument is by juxtaposing it with Russell's response to Bradley's regress; I focus in particular on the concept of ‘unity’. Finally, I offer, in Section 4, a philosophical assessment of the position attributed to Kant in Sections 2 and 3. I argue that, while Kant's account has significant strengths, a number of key areas remain underdeveloped; I suggest that the phenomenological tradition may be read as attempting to fill precisely those gaps. (shrink)

Aims and hypothesesIn an environment of absolute silence, researchers have found many of their participants to perceive phantom sounds. With this between-subject experiment, we aimed to elaborate on these research findings, and specifically investigated whether–in line with the fear-avoidance model of tinnitus perception and reactivity–fear or level of perceived threat influences the incidence and perceptual qualities of phantom sound percepts in an anechoic room. We investigated the potential role of individual differences in anxiety, negative affect, noise sensitivity and subclinical (...) hearing loss. We hypothesized that participants who experience a higher level of threat would direct their attention more to the auditory system, leading to the perception of tinnitus-like sounds, which would otherwise be subaudible, and that under conditions of increased threat, narrowing of attention would lead to perceptual distortions.MethodsIn total, N = 78 normal-hearing volunteers participated in this study. In general, the study sample consisted of young, mostly female, university students. Their hearing was evaluated using gold-standard pure tone audiometry and a speech-in-noise self-test, which is a sensitive screening test to identify subclinical hearing loss. Prior to a four-minute stay in an anechoic room, we randomized participants block design-wise in a threat and no-threat condition. Participants in the threat condition were deceived about their hearing and were led to believe that staying in the room would potentially harm their hearing temporarily. Participants were asked whether they perceived sounds during their stay in the room and rated the perceptual qualities of sound percepts. They were also asked to fill-out standardized questionnaires measuring anxiety, affect and noise sensitivity. The internal consistency of the questionnaires used was verified in our study sample and ranged between α = 0.61 and α = 0.90.ResultsIn line with incidence rates reported in the literature, 74% of our participants reported having heard tinnitus-like sounds in the anechoic room. Speech-in-noise identification ability was comparable for both groups of participants. The experimental manipulation of threat was proven to be effective, as indicated by significantly higher scores on a Threat Manipulation Checklist among participants in the threat condition as compared to those in the no-threat condition. Nevertheless, participants in the threat condition were as likely to report tinnitus percepts as participants in the no-threat condition, and tinnitus percepts were not rated as being louder or more unpleasant as a function of level of threat. For participants who did experience tinnitus percepts, a higher level of threat was associated with a higher degree of experienced unpleasantness. These associations were absent in those who did not experience tinnitus. Higher negative affect was only slightly associated with higher ratings of tinnitus unpleasantness.ConclusionWhereas our threat manipulation was successful in elevating the level of fear, it did not contribute to a higher percentage of participants perceiving tinnitus-like sounds in the threat condition. However, higher levels of perceived threat were related to a higher degree of perceived tinnitus unpleasantness. The findings of our study are drawn from a rather homogenous participant pool in terms of age, gender, and educational background, challenging conclusions that are applicable for the general population. Participants generally obtained normophoric scores on independent variables of interest: they were low anxious, low noise-sensitive, and there was little evidence for the presence of subclinical hearing loss. Possibly, there was insufficient variation in scores to find effects. (shrink)

The function of Metaphysics is to furnish an intelligible and significant perspective. The tendency of recent speculation is to abstain from the attempt to give a total or absolute perspective of the world as a unit—there is some question as to whether we can think of the world as a whole—but rather to understand the objects about us, to bring values, formerly located in a transcendental realm, into life and conduct here and now, and to broaden our understanding and interests (...) to included related activities and other communities. To make our perspective within a single science intelligible it is necessary, as Professor Miller has demonstrated, to fill in the gaps between perceptual objects with inexperienceable “interphenomena” and to employ methodological concepts and principles derived by abstraction and inference. Then again, each of the special sciences selects certain aspects of the general perspective for intensive research leaving gaps between the sciences to be filled in by integrating concepts. Finally, values emerge at the various levels, and these need to be related to the conditions out of which they arise and to the fields of applied knowledge in which they function. (shrink)

This chapter provides a discourse on the meaning of perception and the product of the perceptual process. Perception, at its basic level, is defined as a response to a stimulus, which—under the traditional view of the perceptual process—undergoes further processing in the “Cartesian Theater” of the brain prior to becoming a conscious thought to be appreciated. The chapter goes on to disprove this view, which seems to point to the existence of pre-conscious and conscious states, by proposing the (...) “Multiple Drafts Model,” which assumes that the raw response to stimuli is broken down to interacting micro-drafts in the brain, and is then processed and recombined in real-time in a way that is unbounded by human logic and that precludes the existence of a “pre-conscious state.” Counterarguments for the conclusions reached by Ramachandran in his experiments on the phenomenon of “filling in” are also laid out. (shrink)

A broader conception of the user’s perceptual, cognitive, and motor capabilities considers tools as body extensions. By identifying specific tool-related motor-grounded mechanisms, the embodied approach assumes that this “extensional phenomenon” takes place not only at a behavioral level but also at a psychological level. At least four ways of conceiving embodiment in tool use have been offered in relation to the concepts of incorporation, perception, knowledge, and observation. Nevertheless, the validity of these conceptions has been rarely, if not never, (...) assessed. In this article, we attempt to fill this gap by discussing each of these conceptions in turn, with the aim of determining whether it is justified to consider tools as detached objects of a special sort in embodied terms. We argue that tool incorporation is made possible by “distalization”, that is, an embodied mechanism specific to tool use. Nevertheless, there is neither empirical nor theoretical support for the hypothesis that specific tool-related embodied mechanisms are involved in perception, knowledge, and observation. In broad terms, there is a tendency in the literature to overinterpret tool use as an embodied phenomenon at a psychological level. Inevitably, this limitation leads us to under-intellectualize the underlying cognitive processes and, as a result, it prevents us from understanding the technical-reasoning skills that allow humans to transform dramatically the physical world. (shrink)

David Papineau’s Thinking About Consciousness tells a skillful, inventive, and plausible story about why, given that the phenomenal character of conscious experience is an unproblematically physical property, we continue to suffer from “intuitions of dualism”. According to Papineau, we are misled by the peculiar structure of the phenomenal concepts we use to introspect upon that phenomenal character. Roughly: unlike physical concepts, phenomenal concepts exemplify the kind of experience they are concepts of; and this creates the mistaken impression that the physical (...) concepts leave something out. I find much of Papineau’s account congenial, though I have some questions about his characterization of phenomenal concepts. I will take up two of these questions here. On Papineau’s view, phenomenal concepts are mental terms that are formed by concatenating an experience operator, namely ‘the experience: —’, together with “an actual state of… perceptual classification” (115). The latter state, itself an experience, fills the blank in the experience operator; and the concept thus formed refers to the type of experience whose instances are relevantly similar to that perceptual filling.1 Papineau writes. (shrink)

A serious crisis is identified in theories of neurocomputation, marked by a persistent disparity between the phenomenological or experiential account of visual perception and the neurophysiological level of description of the visual system. In particular, conventional concepts of neural processing offer no explanation for the holistic global aspects of perception identified by Gestalt theory. The problem is paradigmatic and can be traced to contemporary concepts of the functional role of the neural cell, known as the Neuron Doctrine. In the absence (...) of an alternative neurophysiologically plausible model, I propose a perceptual modeling approach, to model the percept as experienced subjectively, rather than modeling the objective neurophysiological state of the visual system that supposedly subserves that experience. A Gestalt Bubble model is presented to demonstrate how the elusive Gestalt principles of emergence, reification, and invariance can be expressed in a quantitative model of the subjective experience of visual consciousness. That model in turn reveals a unique computational strategy underlying visual processing, which is unlike any algorithm devised by man, and certainly unlike the atomistic feed-forward model of neurocomputation offered by the Neuron Doctrine paradigm. The perceptual modeling approach reveals the primary function of perception as that of generating a fully spatial virtual-reality replica of the external world in an internal representation. The common objections to this picture-in-the-head concept of perceptual representation are shown to be ill founded. Key Words: brain-anchored; Cartesian theatre; consciousness; emergence; extrinsic constraints; filling-in; Gestalt; homunculus; indirect realism; intrinsic constraints; invariance; isomorphism; multistability; objective phenomenology; perceptual modeling; perspective; phenomenology; psychophysical parallelism; psychophysical postulate; qualia; reification; representationalism; structural coherence. (shrink)

The segregation of image parts into foreground and background is an important aspect of the neural computation of 3D scene perception. To achieve such segregation, the brain needs information about border ownership; that is, the belongingness of a contour to a specific surface represented in the image. This article presents psychophysical data derived from 3D percepts of figure and ground that were generated by presenting 2D images composed of spatially disjoint shapes that pointed inward or outward relative to the continuous (...) boundaries that they induced along their collinear edges. The shapes in some images had the same contrast (black or white) with respect to the background gray. Other images included opposite contrasts along each induced continuous boundary. Psychophysical results demonstrate conditions under which figure-ground judgment probabilities in response to these ambiguous displays are determined by the orientation of contrasts only, not by their relative contrasts, despite the fact that many border ownership cells in cortical area V2 respond to a preferred relative contrast. Studies are also reviewed in which both polarity-specific and polarity-invariant properties obtain perceptual figure-ground grouping results. The FACADE and 3D LAMINART models are used to explain these data. Keywords: figure-ground separation, border ownership, perceptual grouping, surface filling-in, V2, V4, FACADE Theory. (shrink)

In § 49 of the Critique of the Power of Judgment Kant puts forward a view that the feeling of pleasure in the experience of the beautiful can be stimulated not merely by perceptual properties, but by ideas and thoughts as well. The aim of this paper is to argue that aesthetic ideas fill in the emptiness that abstract and emotion concepts on their own would have without empirical intuitions. That is, aesthetic ideas make these concepts more accessible to (...) us, by creating image schemas that allow us to think about these abstract concepts in a way linked to sensory experience, thereby imbuing them with a more substantive meaning and understanding. (shrink)

This essay begins with a discussion of the phenomenon of filling in. It is argued that filling in is naturally accounted for by taking visual experiences to be importantly like drawn pictures of the world outside. An alternative proposal is then considered, one that models visual experiences on incomplete descriptions. It is shown that introspection does not favor the pictorial view. It is also shown that the phenomenon of blurriness in visual experience does not provide a good reason (...) for favoring the pictorial view either. Why, then, be a pictorialist? It is argued that visual experiences conform to what have been called “the laws of appearance” and that their conformity to these laws gives us an excellent reason for preferring the pictorial account. (shrink)

Pessoa et al. provide a valuable taxonomy of perceptual completion phenomena, but it is not yet clear whether these phenomena are mediated by one kind of neural mechanism or more. We suggest three possible neural mechanisms of long-range interaction to stimulate further perceptual and neurophysiological investigation of perceptual completion and filling-in.

Experimental phenomenology has demonstrated that perception is much richer than stimulus. As is seen in color perception, one and the same stimulus provides more than several modes of appearance or perceptual dimensions. Similarly, there are various perceptual dimensions in form perception. Even a simple geometrical figure inducing visual illusion gives not only perceptual impressions of size, shape, slant, depth, and orientation, but also affective or aesthetic impressions. The present study reviews our experimental phenomenological work on visual illusion (...) and experimental aesthetics, and examines how aesthetic preference is influenced by stimulus factors determining visual illusions including anomalous surface and transparency as well as geometrical illusion. Along with line figures producing geometrical illusions, illusory surface figures inducing neon color spreading and transparency effects were used as test patterns. Participants made both of psychophysical judgments and of aesthetic judgments for the same test pattern. Both of geometrical illusions and aesthetic preferences were found to change similarly as a function of stimulus variables such as the number of filling lines and the size ratio of the inner and outer figural components. Also, following specific stimulus variables such as lightness contrast ratio and spatial interval between inducing figural elements (so called ``packmen''), strong effects of color spreading and transparency were accompanied with strong preferences. It seems that the paradigm to investigate aesthetic phenomena along with perceptual dimensions is useful to bridge the gap between experimental phenomenology and experimental aesthetics. (shrink)

A simple working taxonomy with three classes of pictorial completion is proposed as an alternative to Pessoa et al.'s classification: area, surface, and contour completion. The classification is based on psychophysical evidence, not on the different phenomenal attributes of the stimuli, showing that pictorial completion is likely to involve mechanistic interactions in the visual system at different levels of processing. Whether the concept of “filling-in” is an appropriate metaphor for the visual mechanisms that may underlie perceptual completion is (...) questioned. (shrink)

One reason philosophers have addressed the metaphysics of color is its apparent relevance to the sciences concerned with color phenomena. In the light of such thinking, this paper examines a pairing of views that has received much attention: color physicalism and externalism about the content of perceptual experience. It is argued that the latter is a dubious conception of the workings of our perceptual systems. Together with flawed appeals to the empirical literature, it has led some philosophers to (...) grant color physicalism a scientific legitimacy it does not merit. This discussion provides a useful entry into broader points pertaining to debates about color realism and the relationship between philosophical theories of color and the relevant empirical literatures. A sketch of a novel form of color realism is offered, as is an example that fills in some details of that sketch. (shrink)