Smelling the Brain’s Creation

Much of the philosophical work on perception has focused on vision, with very little discussion of the chemical senses—olfaction and gustation. In this paper, I consider the challenge that olfactory experience presents to upholding a representational view of the sense modalities. Given the phenomenology of olfactory experience, it is difficult to see how a representational view of it might go. Olfaction, then, presents an important challenge for representational theories to overcome. In this paper, I take on this challenge and argue for a representational account of olfactory experience that honors its phenomenology.

This paper considers what olfactory experience can tell us about the controversy over qualia and, in particular, the debate that focuses on the alleged transparency of experience. Although some philosophers claim that transparency holds for all of the sense modalities, any detailed discussion of it focuses on vision. But transparency seems unintuitive for olfactory experience. This paper argues that olfactory experience is indeed transparent and that explanations of what transparency is have been obscured by a reliance on the visual model. In this way, the paper clarifies and advances the debate about transparency.

Review of Philosophy and Psychology, https://link.springer.com/article/10.1007/s13164-023-00707-8, 2023

One of the crucial characteristics of the olfactory modality is that olfactory experiences commonly present odours as pleasant or unpleasant. Indeed, because of the importance of the hedonic aspects of olfactory experience, it has been proposed that the role of olfaction is not to represent the properties of stimuli, but rather to generate a valence-related response. However, despite a growing interest among philosophers in the study of the chemical senses, no dominant theory of sensory pleasure has emerged in the case of human olfaction. The aim of this paper is to develop an argument based on the way in which olfactory valence is neurally encoded; one that demonstrates an advantage of the indicative representational approach to olfactory valence over approaches that characterise valence in terms of desires or commands. The argument shows that it is plausible to understand olfactory valence, at least in part, in terms of indicative representations.

Biological Theory, 2014

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

Journal of Theoretical Biology, 2021

Should theories of “higher-level” cognitive effects originate in “lower-level” molecular mechanisms? This paper supports reductionist explanations of sensory perception via molecular mechanisms in neurobiology. It shows that molecular and cellular mechanisms must constitute the material foundation to derive better theories and models for neuroscience. In support of “bottom-up theorizing”, we explore the recent application of a new real-time molecular imaging technique (SCAPE microscopy) to mixture coding in olfaction. Seemingly emergent “higher level” psychological effects in odor perception, irreducible to the physical stimulus, are linked back to underlying molecular mechanisms at the receptor level. Critical to understanding the importance of the SCAPE study is its notable theoretical impact. It proves a possible answer to the neurocomputational challenge in olfaction from combinatorial coding at the periphery: how does the brain discriminate different complex mixtures from widespread and overlapping receptor activation? The failure of previous reductionist structure-odor explanations is shown to reside in misconceptualizations of the critical causal elements involved. Causally fundamental features are not of parts independently of a mechanism. Components and their relevant features are units via their causal role within a mechanism. Here, new technologies allow revisiting our understanding of the ontology and levels of organization of a system.

Review of Andreas Keller's The Philosophy of Olfaction. Discusses the role of smell in consciousness and the multisensory interactions of smell with vision and other senses.

We can learn much about perceptual experience by thinking about how it can mislead us. In this paper, I explore whether, and how, olfactory experience can mislead. I argue that, in the case of olfactory experience, the traditional distinction between illusion and hallucination does not apply. Integral to the traditional distinction is a notion of ‘object-failure’—the failure of an experience to present objects accurately. I argue that there are no such presented objects in olfactory experience. As a result, olfactory experience can only mislead by means of a kind of property hallucination. The implications of my arguments are twofold. First, we see that accounts of representational content cannot always be based on the visual model. And, secondly, we see that we must recast the notion of non-veridicality, allowing for a notion of non-veridical experience that is disengaged from any particular object.

Psychological Review, 2020

The olfactory system represents the most acute and phylogenetically oldest device that the majority of organisms have to know their physical and social environment. In humans, however, the most predominant functional sense is sight, by virtue of an evolutionary path that has strongly limited the role of olfaction in decision making, social behavior, and cognition. The predominance of sight over smell in humans has important neurobiological, behavioral, and cognitive implications, which are discussed here in a comparative perspective. We propose a theoretical framework in which the psychological determinants of olfactory perception-phenomenological aspects, neuropsychological structures, emotional/ affective correlates, cognitive mechanisms, decision-making dynamics, and behavioral outcomes-are coherently connected and integrated. Implications of this theoretical framework for research and for clinical and diagnostic practice are discussed. The olfactory system represents the most acute and phyloge-netically oldest device that the majority of organisms have for knowing their physical and social environment. The main functions of olfaction involve finding food, communicating and behaving socially and sexually, and avoiding predators and other dangers , thus contributing to survival and adaptation to the living environment (Stevenson, 2010). Going up the evolutionary scale, the importance of olfactory perception decreases. In insects, fishes, and numerous mammals, olfaction plays a key role for the survival of the individual and the species; however, in most primates and birds this sense has increasingly weakened and has partially lost its importance. As MacLean (1973) stated, in more evolved mammals, particularly in humans, the evolution of the brain entailed a shift in the relative influence on sexual and social behavior and communication from olfaction to sight. This change implies not only a "dominance" of one sense over another in driving behavior, but also a broader psychological change in humans' relations with their physical and social environment. Naturally, it is not so easy to separate one sense from another in the process through which living organisms gather information from the external world. The perceptive representations of external objects, phenomena, and events usually combine several perceptual modalities, and this multisensory integration is a peculiar neuropsychological and phe-nomenological characteristic of the perceptual process (Spence, 2015). Nevertheless, as MacLean (1973) argued, while the primitive structure of the brain-the limbic system-is functionally guided by olfaction and this determines an olfactory-centric experience of the living environment, the development of the neocortex in some primates entailed a domination of sight over olfaction for experiencing and exploring the external world. According to MacLean (1973), this radical change from the dominance of olfaction to that of sight opens important anthropo-logical, psychological, and neurobiological issues, not yet completely investigated: "The problem before us now is to inquire how the brain gets out from under the domination of the narcissistic, existential olfactory sense to be altruistically guided by the futuristic , visual sense" (p. 43). In this paper, starting from this question, we will deal with the psychological implications of the shift from an olfactory-centric experience in the living environment-still present in the majority of organisms with a nervous system-to a visuo-centric one typical of human beings. To do so, we will (a) provide a theoretical framework to describe the psychological and epistemological features of olfactory perception, making use of the most recent neuroscience; (b) analyze, in a differential perspective, the features of visuo-centric "construction" of the perceived environment by

Synthese, 2021

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

Philosophical Studies, 2020

Mental Imagery, whereby we experience aspect of a perceptual scene or perceptual object in the absence of direct sensory stimulation is ubiquitous. Often the existence of mental imagery is demonstrated by asking one’s reader to volitionally generate a visual object, such as closing ones eyes and imagining an apple. However, mental imagery also arises in auditory, tactile, interoceptive, and olfactory cases. A number of influential philosophical theories have attempted to explain mental imagery in terms of belief-based forms of representation using the Dependence Thesis, dependence upon means of access, such as enactivisim, or in terms of the similarity ofcontent with perceptual processing. The focus ofthis paper concerns the later approach and in particular assessing if Nanay’s promissory note that his theory is applicable to modalities other than vision, such as smell, seems likely to be of theoretical tender. The thesis argued for in this paper is that olfactory imagery exists and is best accounted for by considering it as a type of perceptual processing with a unique representational format relative to the olfactory perceptual modality. The paper concludes by summarizing the applicability of Nanay’s theory of mental imagery for olfaction and suggests some further issues that arise when transitioning to multi-modal mental imagery.