In this paper I argue that olfactory experience, like visual experience, is exteroceptive: it seems to one that odours, when one smells them, are external to the body, as it seems to one that objects are external to the body when one sees them. Where the sense of smell has been discussed by philosophers, it has often been supposed to be non-exteroceptive. The strangeness of this philosophical orthodoxy makes it natural to ask what would lead to its widespread acceptance. I (...) argue that philosophers have been misled by a visuocentric model of what exteroceptivity involves. Since olfaction lacks the spatial features that make vision exteroceptive the conclusion that olfaction is nonexteroceptive can appear quite compelling, particularly in the absence of an alternative model of exteroceptivity appropriate to olfaction. I offer a model according to which odours seem to be external to the body because they seem to be brought into the nose from without by sniffing and breathing through the nostrils. I argue that some natural-seeming objections to this model rely on substantive assumptions about how the senses are distinguished from one another, and how perceptual experience is put together out of its modality-specific parts, that require defence. (shrink)

The senses, or sensory modalities, constitute the different ways we have of perceiving the world, such as seeing, hearing , touching, tasting, and smelling. But what makes the senses different? How many senses are there? How many could there be? Wha t interaction takes place between the senses? This introduction is a guide to thinking about these questions.

Nowadays, philosophers and scientists tend to agree that, even though human and artificial intelligence work quite differently, they can still illuminate aspects of each other, and knowledge in one domain can inspire progress in the other. For instance, the notion of “artificial” or “synthetic” phenomenology has been gaining some traction in recent AI research. In this paper, we ask the question: what (if anything) is the use of thinking about phenomenology in the context of AI, and in particular machine learning? (...) We will isolate one sense of “phenomenology”, namely the sense in which it is commonly understood within analytic philosophy of perception. Then, we will give examples of projects within sensory substitution and restoration science that rely heavily on machine learning and to which, according to us, phenomenology in the sense specified makes a relevant contribution. Finally, we will shed some light on what this contribution looks like and why it is important. (shrink)

Philosophers and cognitive scientists of perception by custom have investigated individual sense modalities in relative isolation from each other. However, perceiving is, in a number of respects, multimodal. The traditional sense modalities should not be treated as explanatorily independent. Attention to the multimodal aspects of perception challenges common assumptions about the content and phenomenology of perception, and about the individuation and psychological nature of sense modalities. Multimodal perception thus presents a valuable opportunity for a case study in mature interdisciplinary cognitive (...) science. This chapter aims to raise these issues against the background of unimodal approaches in the study of perception. It presents some of the central empirical findings concerning multimodality, and it explains the philosophical implications of these findings. Foremost, it aims to encourage and open avenues for future research. (shrink)

Cross-modal perceptual illusions occur when a stimulus to one modality impacts perceptual experience associated with another modality. Unlike synaesthesia, cross-modal illusions are intelligible as results of perceptual strategies for dealing with sensory stimulation to multiple modalities, rather than as mere quirks. I argue that understanding cross-modal illusions reveals an important flaw in a widespread conception of the senses, and of their role in perceptual experience, according to which understanding perception and perceptual experience is a matter of assembling independently viable stories (...) about vision, audition, olfaction, and the rest. (shrink)

I argue that we should reject the sparse view that there are or could be only a small number of rather distinct senses. When one appreciates this then one can see that there is no need to choose between the standard criteria that have been proposed as ways of individuating the senses—representation, phenomenal character, proximal stimulus and sense organ—or any other criteria that one may deem important. Rather, one can use these criteria in conjunction to form a fine-grained taxonomy of (...) the senses. We can think of these criteria as defining a multidimensional space within which we can locate each of the senses that we are familiar with and which also defines the space of possible senses there could be. (shrink)

Block (Trends Cogn Sci 7:285–286, 2003) and Prinz (PSYCHE 12:1–19, 2006) have defended the idea that SSD perception remains in the substituting modality (auditory or tactile). Hurley and Noë (Biol Philos 18:131–168, 2003) instead argued that after substantial training with the device, the perceptual experience that the SSD user enjoys undergoes a change, switching from tactile/auditory to visual. This debate has unfolded in something like a stalemate where, I will argue, it has become difficult to determine whether the perception acquired (...) through the coupling with an SSD remains in the substituting or the substituted modality. Within this puzzling deadlock two new approaches have been recently suggested. Ward and Meijer (Conscious Cogn 19:492–500, 2010) describe SSD perception as visual-like but characterize it as a kind of artificially induced synaesthesia. Auvray et al. (Perception 36:416–430, 2007) and Auvray and Myin (Cogn Sci 33:1036–1058, 2009) suggest that SSDs let their users experience a new kind of perception. Deroy and Auvray (forthcoming) refine this position, and argue that this new kind of perception depends on pre-existing senses without entirely aligning with any of them. So, they have talked about perceptual experience in SSDs as going "beyond vision". In a similar vein, MacPherson (Oxford University Press, New York, 2011a) claims that “if the subjects (SSD users) have experiences with both vision-like and touch-like representational characteristics then perhaps they have a sense that ordinary humans do not” (MacPherson in Oxford University Press, New York, 2011a, p. 139). (shrink)

I consider the role of psychology and other sciences in telling us about our senses, via the issue of whether empirical findings show us that flavours are perceived partly with the sense of smell. I argue that scientific findings do not establish that we're wrong to think that flavours are just tasted. Non-naturalism, according to which our everyday conception of the senses does not involve empirical commitments of a kind that could be corrected by empirical findings is, I suggest, a (...) plausible view that is not easy to dismiss. (shrink)

In philosophical discussions of the secondary qualities, color has taken center stage. Smells, tastes, sounds, and feels have been treated, by and large, as mere accessories to colors. We are, as it is said, visual creatures. This, at least, has been the working assumption in the philosophy of perception and in those metaphysical discussions about the nature of the secondary qualities. The result has been a scarcity of work on the “other” secondary qualities. In this paper, I take smells and (...) place them front and center. I ask: What are smells? For many philosophers, the view that colors can be explained in purely physicalistic terms has seemed very appealing. In the case of smells, this kind of nonrelational view has seemed much less appealing. Philosophers have been drawn to versions of relationalism—the view that the nature of smells must be explained (at least in part) in terms of the effects they have on perceivers. In this paper, I consider a contemporary argument for this view. I argue that nonrelationalist views of smell have little to fear from this argument. (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)

This paper addresses the nature of touch or ?tactual perception?. I argue that touch encompasses a wide range of perceptual achievements, that treating it as a number of separate senses will not work, and that the permissive conception we are left with is so permissive that it is unclear how touch might be distinguished from the other senses. I conclude that no criteria will succeed in individuating touch. Although I do not rule out the possibility that this also applies to (...) other senses, I suggest that the heterogeneity of touch makes it both distinctive and particularly problematic. (shrink)

How do we individuate the senses, what exactly do we do when we do so, and why does it matter? In the following article, I propose a general answer to these related questions based on Franz Brentano's views on the senses. After a short survey of various answers offered in the recent literature on the senses, I distinguish between two major ways of answering this question, causally and descriptively, arguing that only answers giving priority to description and to the classification (...) involved in it are on the right track for a general answer to the related questions. In the second part of the article, I argue that Brentano's descriptive psychology is an attractive candidate for such an answer. His descriptive psychology provides a plausible account of the classification involved in description, in particular regarding the classification of sensory qualities. I close the article by briefly explaining how Brentano spells out the priority of descriptive answers over causal ones. (shrink)

I argue for sensory pluralism. This is the view that there are many forms of sensory interaction and unity, and no single category that classifies them all. In other words, sensory interactions do not form a single natural kind. This view suggests that how we classify sensory systems (and the experiences they generate) partly depends on our explanatory purposes. I begin with a detailed discussion of the issue as it arises for our understanding of thermal perception, followed by a general (...) account and defense of sensory pluralism. (shrink)

Keeley has recently argued that the philosophical issue of how to analyse the concept of a sense can usefully be addressed by considering how scientists, and more specifically neuroethologists, classify the senses. After briefly outlining his proposal, which is based on the application of an ordered set of individually necessary and jointly sufficient conditions for modality differentiation, I argue, by way of two complementary counterexamples, that it fails to account fully for the way the senses are in fact individuated in (...) neuroethology and other relevant sciences. (shrink)

Is the flavor of mint reducible to the minty smell, the taste, and the menthol-like coolness on the roof of one’s mouth, or does it include something over and above these—something not properly associated with any one of the contributing senses? More generally, are there features of perceptual experiences—so-called novel features—that are not associated with any of our senses taken singly? This question has received a lot of attention of late. Yet surprisingly little attention has been paid to the question (...) of what it means to say that a feature is associated with a sensory modality in the first place. Indeed, there is only one fully developed proposal in the literature, due to Casey O’Callaghan. I argue that this proposal is too permissive to inform the debate over novel features. I go on to argue that all attempts to formulate a better proposal along these lines fail. The corollary of my arguments is that the question of the existence of novel features is poorly formed. Furthermore, the problem generalizes, with the result that we should not rely on our pre-theoretical notions of the senses as the basis of theorizing about the features of perceptual experiences. (shrink)

It is part of the phenomenology of perceptual experiences that objects seem to be presented to us. The first guide to objects is their perceptual presence. Further reflection shows that we take the objects of our perceptual experiences to be among the causes of our experiences. However, not all causes of the experience are also objects of the experience. This raises the question indicated in the title of this paper. We argue that taking phenomenal presence as the guide to the (...) objects of perception, we can see that at least in two sensory modalities, smell and touch, there is no uniform answer to this question. The objects of olfactory and tactile experiences can move along the causal chain. Accordingly, the content of olfactory and tactile experience may vary. (shrink)

It is hoped that modern sensory substitution and augmentation devices will be able to replace or expand our senses. But to what extent has this been achieved to date? To what extent are the experiences created by sensory substitution devices like the sensory experiences that we are trying to replace? To what extent can we augment people’s senses providing them with new information and new experiences? The first aim of this introduction is to delve deeply into this question to discover (...) the usefulness of these devices, to outline the different sorts of experience that might be created, and what the evidence tells us about these experiences. While there are some reasons to be hopeful about the powers of sensory substitution devices, there are also reasons to wonder whether they will ever really have the practical applications that we hope they might have. The second aim is to look to see whether the study of modern sensory substitution and augmentation devices can shed light on the nature of our senses and perception in general. Much of the philosophical, psychological, and neuroscientific work that takes place concerning sensory substitution and augmentation is keenly aware of the possibility that it might help our understanding and it seeks to comprehend many different aspects of perception. (shrink)

There has been some recent optimism that addressing the question of how we distinguish sensory modalities will help us consider whether there are limits on a scientific understanding of perceptual states. For example, Block has suggested that the way we distinguish sensory modalities indicates that perceptual states have qualia which at least resist scientific characterization. At another extreme, Keeley argues that our common-sense way of distinguishing the senses in terms of qualitative properties is misguided, and offers a scientific eliminativism about (...) common-sense modalities which avoids appeal to qualitative properties altogether. I’ll argue contrary to Keeley that qualitative properties are necessary for distinguishing senses, and contrary to Block that our common-sense distinction doesn’t indicate that perceptual states have qualia. A non-qualitative characterization of perceptual states isn’t needed to avoid the potential limit on scientific understanding imposed by qualia. (shrink)

How should interaction between the senses affect thought about them? I try to capture some ways in which non sense-specific perception might be thought to make it impossible or pointless or explanatorily idle to distinguish between senses. This task is complicated by there being more than one view of the nature of the senses, and more than one kind of non sense-specific perception. I argue, in particular, that provided we are willing to forgo certain assumptions about, for instance, the relationship (...) between modes or kinds of experience, and about how one should count perceptual experiences at a time, at least one way of thinking about the senses survives the occurrence of various kinds of non sense-specific perception relatively unscathed. (shrink)

Representationalist theories of sensory experience are often thought to be vulnerable to the existence of apparently non-representational differences between experiences in different sensory modalities. Seeing and hearing seem to differ in their qualia, quite apart from what they represent. The origin of this idea is perhaps Grice’s argument, in “Some Remarks on the Senses,” that the senses are distinguished by “introspectible character.” In this chapter I take the Representationalist side by putting forward an account of sense modalities which is consistent (...) with that view and yet pays due regard to the intuition behind Grice’s argument. Employing J.J. Gibson’s distinction between exploratory and performatory behaviour, I point to a proprioceptive element in perceptual experience, and identify this as crucial in any account of what makes a particular way of perceiving a sense modality. (shrink)

Suppose someone hears a loud noise and at the same time sees a yellow flash. It seems hard to deny that the person can experience loudness and yellowness together. However, since loudness is experienced by the auditory sense whereas yellowness is experienced by the visual sense it also seems hard to explain how.

Cognition is not, and could not possibly be, entirely representational in character. There is also a phenomenal form of cognitive expression that registers the intrinsic properties of mental states themselves. Arguments against the reality of this intrinsic phenomenal dimension to mental experience have focused either on its supposed impossibility, or secondly, the non-appearance of any such qualities to introspection. This paper argues to the contrary, that the registration of cognitive state properties does take place independently of representational content; and necessarily (...) so, since it supports an independent function—self-management. Given the fact that unlike a computer, the brain must, of necessity, operate itself, it needs to be in touch with itself to do so. Intrinsic phenomenal forms of cognitive expression allow the brain to do just that by registering characteristics of the cognitive states themselves. Self-management might well prove to constitute the prime reason for the emergence of subjectivity itself. (shrink)

According to an ordinary view, we distinguish, classify, and appreciate food and beverages according to their taste. However, scientists seem to disagree with this naive view. They maintain that we don't really perceive the lemony taste of a cake or the delicate smoky taste of a single-malt whiskey, because what we ascribe to taste is in reality mostly perceived by smell. As opposed to this scientific consensus regarding taste, I will defend a naive view of taste and deny that olfaction (...) is involved in what we naively call taste. Like the uninformed layman, I will maintain that when I eat a strawberry, what I really perceive is its taste, not its smell or flavor. (shrink)

Sympathetic magic features strongly in virtually all religious traditions and in folk customs generally. Scholars agree that It is based on the association of ideas perceived as external, mind-independent causal realities, as connections mediating causal influence. Moreover, religious folk believe that this mediation involves forms of supernatural agency. From a psychological perspective, the key question revolves around the principles by which the cognitive system deems some of its content to reference the external world and other content to constitute internal mental (...) forms of activity like thoughts, feelings and attitudes. The paper proposes that the critical factor has to do with the balance between two distinctly different kinds of cognitive content: representations of things (mentation arising in the form of something other than itself), as distinct from registrations referencing the intrinsic phenomenal properties of the mental state itself. The balance between these two determines whether content is perceived as external worldly event or a form of internal mental content. (shrink)

The discovery of mirror neurons has been hailed as one of the most exciting developments in neuroscience in the past few decades. These neurons discharge in response to the observation of others’ actions. But how are we to understand the function of these neurons? In this paper I defend the idea that mirror neurons are best conceived as components of a sensory system that has the function to perceive action. In short, mirror neurons are part of a hitherto unrecognized “sixth (...) sense”. In this spirit, research should move toward developing a psychophysics of mirror neurons. (shrink)

In Western common sense, one speaks of there being five human senses, a claim apparently challenged by the biological and psychological sciences. Part of this challenge comes in the form of claiming the existence of additional senses. Part of the challenge comes from positing multiple senses where common sense only speaks of one, such as with the fractionation of “touch” into pressure and temperature senses. One conceptual difficulty in thinking about the number and division of senses is that it's not (...) clear whether the different senses constitute natural kinds and, if not, what kind of kind they are. Should we favor antirealism with respect to the senses, akin to the arguments of some concerning the nature of species or race? I will argue that this first problem is compounded by another: that we ought to be pluralists with respect to the senses—what is meant by the term “sense” varies from context to context, varying even between scientific contexts. (shrink)