The sensory constraint on conscious thought says that if a thought is phenomenally conscious, its phenomenal properties must be reducible to some sensory phenomenal character. I argue that the burgeoning psychological literature on aphantasia, an impoverishment in the ability to generate mental imagery, provides a counterexample to the sensory constraint. The best explanation of aphantasics’ introspective reports, neuroimaging, and task performance is that some aphantasics have conscious thoughts without sensory mental imagery. This argument against the sensory constraint supports the (...) existence of a non-sensory phenomenology of thought. Moreover, this argument can be extended to show that this non-sensory phenomenology determines a thought content. Finally, it can potentially diagnose the disagreement over cognitive phenomenology in the philosophy of mind, as such disagreement may turn on interpersonal variation in mental imagery. (shrink)

Though researchers working on congenital aphantasia (henceforth “aphantasia”) agree that this condition involves an impairment in the ability to voluntarily generate visual imagery, disagreement looms large as to which other impairments are exhibited by aphantasic subjects. This article offers the first extensive review of studies on aphantasia, and proposes that aphantasic subjects exhibit a cluster of impairments. It puts forward a novel cognitive theory of aphantasia, building on the constructive episodic simulation hypothesis of memory and imagination. (...) It argues that aphantasia is best explained as a malfunction of processes in the episodic system, and is therefore an episodic system condition. (shrink)

Aphantasia is a condition characterised by a deficit of mental imagery. Since several psychopathologies are partially maintained by mental imagery, it may be illuminating to consider the condition against the background of psychological disorder. After outlining current findings and hypotheses regarding aphantasia and psychopathology, this paper suggests that some support for defining aphantasia as a lack of voluntary imagery may be found here. The paper then outlines potentially fruitful directions for future research into aphantasia in general (...) and its relation to psychopathology in particular, including rethinking use of the SUIS to measure involuntary imagery, whether aphantasia offers protection against addiction, and whether hyperphantasia is a potential risk factor for maladaptive daydreaming, among others. (shrink)

Aphantasia is a recently discovered disorder characterised by the total incapacity to generate visual forms of mental imagery. This paper proposes that aphantasia raises important theoretical concerns for the ongoing debate in the philosophy and science of consciousness over the nature of dreams. Recent studies of aphantasia and its neurobehavioral correlates reveal that the majority of aphantasics, whilst unable to produce visual imagery while awake, nevertheless retain the capacity to experience rich visual dreams. This finding constitutes a (...) novel explanandum for theories of dreaming. Specifically, I argue that the recent dream reports of aphantasics constitute an empirical challenge to the emerging family of views which claim that dreams are essentially imaginative experiences, constitutively involving the kinds of mental imagery which aphantasics, ex-hypothesi, lack. After presenting this challenge in the context of Jonathan Ichikawa’s recent arguments for this view, I argue that this empirical challenge may be overcome if the imagination theorist abandons Ichikawa’s account of dreaming in favour of a modified version. This involves the claim that dreams are essentially inactive and constitutively involve non voluntary forms of imagination. I conclude with a suggestion for further research which can test the viability of this alternative hypothesis, and move the debate forward. (shrink)

According to a common view, conscious thoughts necessarily involve quasi-perceptual experiences, or mental images. This is alleged to be the case not only when one entertains conscious thoughts about perceptible things, but also when one thinks about more abstract things. In the case of conscious abstract propositional thoughts, the idea is that they occur in inner speech, which is taken to involve imagery (typically auditory) of words in a natural language. I argue that unsymbolized thinking and total aphantasia cast (...) doubt on this common view. Unsymbolized thinking is the experience of thoughts that does not involve imagery. Total aphantasia is the inability to produce mental images of all sensory modalities. I consider and reject the objection that these individuals are mistaken either because their thoughts do involve images, or because those thoughts are not conscious. Thus, unsymbolized thinking and aphantasia provide evidence that conscious thoughts can occur without imagery. (shrink)

Aphantasia, a recently labelled spectrum condition affecting mental imagery, has brought to the fore the centrality of imagination in our lives. Intuitively it may seem that we cannot have a normal life without the possession of imaginative abilities. Yet, aphantasics do not seem to be much affected by their condition. Can aphantasia tell us anything about the nature and role of our imaginative abilities? I contend that an important distinction that can shed light on this question has been (...) largely overlooked, namely that between two senses of mental imagery: as a type of mental content (viz., mental imagery strictly speaking), and as a kind of psychological attitude (viz., sensory imagination). Drawing on this distinction, I suggest three possible conditions: (i) impairment in mental imagery only, (ii) impairment in sensory imagination only, (iii) impairment in both mental imagery and sensory imagination. I show that core cases of aphantasia are better understood as impairments in sensory imagination only, but I indicate empirical strategies to investigate whether some cases of aphantasia rather involve impairments in mental imagery, which would point toward a plurality of forms of aphantasia. Sensory imagination, however, does not exhaust the imaginative realm, therefore we shouldn’t jump to the hasty conclusion that aphantasics have no imagination. Most aphantasics lack sensory imagination, but arguably can exploit other forms of imagination. This would explain in which sense they still possess imaginative abilities. (shrink)

Aphantasia is a condition that is often characterized as the impaired ability to create voluntary mental images. Aphantasia is assumed to selectively affect voluntary imagery mainly because even though aphantasics report being unable to visualize something at will, many report having visual dreams. We argue that this common characterization of aphantasia is incorrect. Studies on aphantasia are often not clear about whether they are assessing voluntary or involuntary imagery, but some studies show that several forms of (...) involuntary imagery are also affected in aphantasia (including imagery in dreams). We also raise problems for two attempts to show that involuntary images are preserved in aphantasia. In addition, we report the results of a study about afterimages in aphantasia, which suggest that these tend to be less intense in aphantasics than in controls. Involuntary imagery is often treated as a unitary kind that is either present or absent in aphantasia. We suggest that this approach is mistaken and that we should look at different types of involuntary imagery case by case. Doing so reveals no evidence of preserved involuntary imagery in aphantasia. We suggest that a broader characterization of aphantasia, as a deficit in forming mental imagery, whether voluntary or not, is more appropriate. Characterizing aphantasia as a volitional deficit is likely to lead researchers to give incorrect explanations for aphantasia, and to look for the wrong mechanisms underlying it. (shrink)

Though researchers working on congenital aphantasia (henceforth “aphantasia”) agree that this condition involves an impairment in the ability to voluntarily generate visual imagery, disagreement looms large as to which other impairments are exhibited by aphantasic subjects. This article offers the first extensive review of studies on aphantasia, and proposes that aphantasic subjects exhibit a cluster of impairments. It puts forward a novel cognitive theory of aphantasia, building on the constructive episodic simulation hypothesis of memory and imagination. (...) It argues that aphantasia is best explained as a malfunction of processes in the episodic system, and is therefore an episodic system condition. (shrink)

Testimonies about aphantasia are still surprisingly rare, more than a century after Galton. It is therefore difficult to understand how a person devoid of (a kind of) imagination actually thinks. In order to outline "what it is like" to be aphantasic, I will start by compiling two qualitative interviews with aphantasics that I will then compare with other testimonies collected in literature and online. The fact that aphantasia is poorly documented may also explain why few philosophers (with the (...) notable exception of Phillips 2014) seem to take this phenomenon seriously – contrary to others phenomena such as blindsight for instance. To redress the balance, the second part of this paper will consider three debates to which aphantasia could contribute. (shrink)

In the last six or seven years, aphantasia has received attention from media outlets, television shows, and social networks. This alleged condition, however, has hardly been discussed in the philosophy of mind. In this paper, I assess some of the research conducted in cognitive science and provide, for the first time in the literature, a comprehensive assessment of possible explanations for aphantasia. Specifically, the hypotheses I submit for consideration ascribe the reports of absence of visual imagery to (i) (...) a discrepancy at the level of concepts, (ii) a failure of attentional mechanisms that modulate introspection, (iii) a lack of personal-level access to sub-personal imagistic representations, and (iv) an absence of sub-personal imagistic representations. I conclude that hypotheses (i) and (ii) can be rejected while hypotheses (iii) and (iv) can be accepted as defensible candidates for explaining aphantasia, although the latter is better suited to account for the available evidence in both comparative and absolute terms. Finally, I present some educated guesses and empirical research that could shed further light on the study of this condition. (shrink)

Episodic memory (EM) involves re-experiencing past experiences by means of mental imagery. Aphantasics (who lack mental imagery) and people with severely deficient autobiographical memory (SDAM) lack the ability to re-experience, which would imply that they don't have EM. However, aphantasics and people with SDAM have personal and affective memories, which are other defining aspects of EM (in addition to re-experiencing). This suggests that these supposed aspects of EM really are independent faculties or modules of memory, and that EM is a (...) composite faculty rather than a natural kind. Apparent varieties of (normal and "defective") EM (as well as some closely related kinds of memory) are different combinations of these modules, and the EM construct itself adds little if any explanatory value to these modules. (shrink)

Recently, the term ‘aphantasia’ has become current in scientific and public discourse to denote the absence of mental imagery. However, new terms for aphantasia or its subgroups have recently been proposed, e.g. ‘dysikonesia’ or ‘anauralia’, which complicates the literature, research communication and understanding for the general public. Before further terms emerge, we advocate the consistent use of the term ‘aphantasia’ as it can be used flexibly and precisely, and is already widely known in the scientific community and (...) among the general public. (shrink)

Aphantasia is a heterogeneous neuropsychological syndrome consisting of the inability to create mental images. We argue that its progressive form may be a harbinger of dementia. Aphantasia may manifest as the inability to create any mental images or to create complex scenes, inability to spontaneously initiate generation of mental images, and/or inability to visualize a sequence of events.

ABSTRACT Aphantasia is a spectrum disorder, affecting the ability of otherwise healthy individuals to form voluntary or conscious mental images, and in some cases also any form of sensory representation. Although only discovered in 2010, it is now estimated that 2–3% of the population may have aphantasia – otherwise termed, the absence of a ‘mind’s eye,’ that aspect of conscious experience which so many people take for granted as part of their general way of experiencing the world. (...) class='Hi'>Aphantasia, although it does not imply the absence of all forms of imagination, such as perspective taking and narrative construction, is quite literally a disorder affecting the individual’s capacity to form and work with images, and thus the absence of a certain way in which consciousness engages with the image-object, distinct both from perception and thought. This paper examines how phenomenological accounts of imagination can help us to better understand aphantasia, and also the ways in which aphantasia calls into question some aspects of an existential account of self. (shrink)

Predictive processing (PP) accounts of perception are unique not merely in that they postulate a unity between perception and imagination. Rather, they are unique in claiming that perception should be conceptualised in terms of imagination and that the two involve an identity of neural implementation. This paper argues against this postulated unity, on both conceptual and empirical grounds. Conceptually, the manner in which PP theorists link perception and imagination belies an impoverished account of imagery as cloistered from the external world (...) in its intentionality, akin to a virtual reality, as well as endogenously generated. Yet this ignores a whole class of imagery whose intentionality is directed on the actual environment—projected mental imagery—and also ignores the fact that imagery may be triggered crossmodally in a bottom-up, stimulus-driven way. Empirically, claiming that imagery and perception share neural circuitry ignores relevant clinical results in this area. These evidence substantial perception/imagery neural dissociations, most notably in the case of aphantasia. Taken together, the arguments here suggest that PP theorists should substantially temper, if not outright abandon, their claim to a perception/imagination unity. (shrink)

How tight is the conceptual connection between imagination and perception? A number of philosophers, from the early moderns to present-day predictive processing theorists, tie the knot as tightly as they can, claiming that states of the imagination, i.e. mental imagery, are a proper subset of perceptual experience. This paper labels such a view ‘perceptualism’ about the imagination and supplies new arguments against it. The arguments are based on high-level perceptual content and, distinctly, cognitive penetration. The paper also defuses a recent, (...) influential argument for perceptualism based on the ‘discovery’ that visual perception and mental imagery share a significant neural substrate: circuitry in V1, the brain’s primary visual cortex. Current neuropsychology is shown to be equivocal at best on this matter. While experiments conducted on healthy, neurotypical subjects indicate substantial neural overlap, there is extensive clinical evidence of dissociations between imagery and perception in the brain, most notably in the case of aphantasia. (shrink)

First described by Galton in 1880 and then remaining unnoticed for a century, recent investigations in neuroscience have shown that a condition called aphantasia appears in certain individuals, which causes them to be unable to experience visual mental imagery. Comparing aphantasia to hyperphantasia – i.e., photo-like memory – and considering the neurological basis of perceptual phenomena, we are revisiting Hume's division of perceptions into impressions and ideas. By showing different vivacities of mental phenomena and comparing them to neurological (...) research, we are stating that not only impressions and ideas differ "in the degrees of force and liveliness", but ideas and impressions amongst themselves as well. Such a gradual range of perceptions and mental images bears significant consequences for not only representational theory and historical interpretations, but linguistics and semiotics as well. (shrink)

What is the relationship between perception and mental imagery? I aim to eliminate an answer that I call perceptualism about mental imagery. Strong perceptualism, defended by Bence Nanay, predictive processing theorists, and several others, claims that imagery is a kind of perceptual state. Weak perceptualism, defended by M. G. F. Martin and Matthew Soteriou, claims that mental imagery is a representation of a perceptual state, a view sometimes called The Dependency Thesis. Strong perceptualism is to be rejected since it misclassifies (...) imagery disorders and abnormalities as perceptual disorders and abnormalities. Weak Perceptualism is to be rejected since it gets wrong the aim and accuracy conditions of a whole class of mental imagery–projected mental imagery–and relies on an impoverished concept of perceptual states, ignoring certain of their structural features. Whatever the relationship between perception and imagery, the perceptualist has it wrong. (shrink)

This paper introduces a novel conceptualisation of mental imagery; namely, that is grease for the mind’s gears (MGT). MGT is not just a metaphor. Rather, it describes an important and overlooked higher-order function of mental imagery: that it aids various mental faculties discharge their characteristic functional roles. MGT is motivated by reflection on converging evidence from clinical, experimental and social psychology and solves at least two neglected conceptual puzzles about mental imagery. The first puzzle concerns imagery’s architectural promiscuity; that is, (...) its ability to assist diverse mental faculties and perform many different functions when doing so. The second puzzle concerns how to square imagery’s architectural promiscuity with its psychopathological relevance; that is, its being a maintaining cause, and possibly even a partial constituent, of several psychological disorders, including post-traumatic stress disorder, bipolar disorder and major depressive disorder. Mental imagery helps and harms human psychology to extreme degrees and this is something that calls for elucidation. MGT says that instead of facing perplexing heterogeneities here, we instead face a significant unity. On this score, MGT is argued to be superior to the currently dominant conception of imagery in the philosophical literature; namely, as a perception-like state of mind. (shrink)

Historically, mental imagery has been defined as an experiential state - as something necessarily conscious. But most behavioural or neuroimaging experiments on mental imagery - including the most famous ones - don’t actually take the conscious experience of the subject into consideration. Further, recent research highlights that there are very few behavioural or neural differences between conscious and unconscious mental imagery. I argue that treating mental imagery as not necessarily conscious (as potentially unconscious) would bring much needed explanatory unification to (...) mental imagery research. It would also help us to reassess some of the recent aphantasia findings inasmuch as at least some subjects with aphantasia would be best described as having unconscious mental imagery. (shrink)

How does visual imagination differ from visual perceptual experience? And how should we describe experiences of visual imagery? Moreover how can people who have visual imagery convey what it is like to have it to those who have never had it – congenital aphantisics? This paper addresses these questions using examples of illusions and other perceptual phenomena to hone in on the answers.

The question of whether our conscious experience is rich or sparse remains an enduring controversy in philosophy. The “overflow” account argues that perceptual consciousness is far richer than cognitive access: when perceiving a complex scene, subjects see more than they can report. This paper draws on aphantasia to propose a new argument in favor of overflow. First, it shows that opponents of overflow explain subjects’ performance in a change detection paradigm by appealing to a type of “internal imagery.” Second, (...) it provides empirical evidence to demonstrate that aphantasics are incapable of generating this imagery. However, aphantasics perform equally well in this task; and so the no-overflow account fails to explain their performance. This means that proponents of this view are committed to an unsupported view of perception. (shrink)

One of the main fields of consciousness studies is the search for the function of consciousness. The article deals with the hypothesis of the function of imagination as an attribute of consciousness. In the regard of the issues of the attributes of consciousness, the author analyzes the phenomenon of aphantasia, that is, lack of imagination. Despite the lack of formalized ideas about the function of consciousness and despite the scientific trend of the narrowing research areas where subjective experience is (...) necessary for a normal behavior of brain, there is a tendency to expand the presence of consciousness in the world in the modern Western philosophy of consciousness. The result of this “emancipation of consciousness” is the idea of the theoretical essential closeness of a human being and other agents: animals, artificial intelligence, plants. A consequence of the “emancipation of consciousness” is the emergence of modern versions of panpsychism, which propose expanding the space of consciousness to the world as a whole. However, studies in the field of conscious cognitive processes show that the processes that need the participation of consciousness, according to the standard intuitions, in some cases successfully performed without it. For example, the phenomenon of aphantasia shows that the tasks of imagination are performed in the absence of the ability to imagine. Therefore, it is important to take also into account the theoretical possibility of the lack of the realization of the function of consciousness. This makes it possible to ask a question about the presence of consciousness in the space that is traditionally endowed with consciousness, according to the dominant views in philosophy. Therefore, by approaching the question of the attributes of consciousness, the author demonstrates the limitations of the program for the emancipation of consciousness and offers an alternative solution to the question of the scale of the presence of consciousness in the world. (shrink)

Nanay (2017) argues for unconscious mental imagery, inter alia based on the assumption that successful performance in imagery tasks requires the manipulation of mental imagery. I challenge this assumption with the help of results presented in Shepard and Metzler (1971), Zeman et al. (2010), and Keogh and Pearson (2018). The studies suggest that imagery tasks can be successfully performed by means of cognitive/propositional strategies which do not rely on imagery.

While discussions of the imagination have been limited in philosophy of science, this is beginning to change. In recent years, a vast literature on imagination in science has emerged. This paper surveys the current field, including the changing attitudes towards the scientific imagination, the fiction view of models, how the imagination can lead to knowledge and understanding, and the value of different types of imagination. It ends with a discussion of the gaps in the current literature, indicating avenues for future (...) research. (shrink)