Mind &Language, Volume 35, Issue 1, Page 90-114, February 2020.

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

Several theorists argue that one does not experience something as being at or coming from a distance or direction in olfaction. In contrast to this, I suggest that there can be a variety of spatial aspects of both synchronic and diachronic olfactory experiences, including spatial distance and direction. I emphasise, however, that these are not aspects of every olfactory experience. Thus, I suggest renouncing the widespread assumption there is a uniform account of the nature, including the spatial nature, of what (...) is experienced in olfactory experience. (shrink)

We perceive smells as perduring complex entities within a distal array that might be conceived of as smellscapes. However, the philosophical orthodoxy of Odor Theories has been to deny that smells are perceived as having a distal location. Recent challenges have been mounted to Odor Theories’ veracity in handling the timescale of olfactory perception, how it individuates odors as a distal entities, and their claim that olfactory perception is not spatial. The paper does not aim to dispute these criticisms. Rather, (...) what will be shown is that Molecular Structure Theory, a refinement of Odor Theory, can be further developed to handle these challenges. The theory is further refined by focusing on distal perception that requires considering the perceptual object as mereologically complex persisting odor against a background scene conceived of as a smellscape. What will be offered is an expansion of Molecular Structure Theory to account for distal smell perception within natural environments. (shrink)

Does the sense of smell involve the perception of odor objects? General discussion of perceptual objecthood centers on three criteria: stimulus representation; perceptual constancy; and figure-ground segregation. These criteria, derived from theories of vision, have been applied to olfaction in recent philosophical debates about psychology. An inherent problem with such framing of olfactory objecthood is that philosophers explicitly ignore the constitutive factors of the sensory systems that underpin the implementation of these criteria. The biological basis of odor coding is fundamentally (...) different from the coding principles of the visual system. This article analyzes the three measures of perceptual objecthood against the biological background of the olfactory system. It contrasts the coding principles in olfaction with the visual system to show why these criteria of objecthood fail to be instantiated in odor perception. The argument demonstrates that olfaction affords perceptual categorization without the need to form odor objects. (shrink)

Theories of perception have traditionally dismissed the sense of smell as a notoriously variable and highly subjective sense, mainly because it does not easily fit into accounts of perception based on visual experience. So far, philosophical questions about the objects of olfactory perception have started by considering the nature of olfactory experience. However, there is no philosophically neutral or agreed conception of olfactory experience: it all depends on what one thinks odors are. We examine the existing philosophical methodology for addressing (...) our sense of smell: on the one hand appeals to phenomenology that focus on the experiential dimensions of odor perception and on the other approaches that look at odor sources and their material dimensions. We show that neither strategy provides enough information to account for the human sense of smell and argue that the inclusion of the missing dimension of biology, with its concern for the function (or functions) of olfaction, provides the means to develop a satisfactory and empirically informed philosophy of smell. (shrink)

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

While there is a growing philosophical interest in analysing olfactory experiences, the mereological structure of odours considered in respect of how they are perceptually experienced has not yet been extensively investigated. The paper argues that odours are perceptually experienced as having a mereological structure, but this structure is significantly different from the spatial mereological structure of visually experienced objects. Most importantly, in the case of the olfactory part-structure, the classical weak supplementation principle is not satisfied. This thesis is justified by (...) referring to empirical results in olfactory science concerning the human ability to identify components in complex olfactory stimuli. Further, it is shown how differences between olfactory and visual mereologies may arise from the way in which these modalities represent space. (shrink)

The chapter unfolds in the following sections. The first section exam- ines the reasons for claiming that olfactory perception is spatially unstruc- tured and our experience of smells has an abstract structure. The second section elucidates the further arguments that olfaction cannot generate figure-ground segregation. The third section assesses the conclusion that olfactory perception and experience cannot solve the MPP. Following the overview of the many problems inherent to distal olfactory percep- tion, MST will be introduced as an alternative perspective (...) that allows for figure-ground segregation and perceiving multiple olfactory objects within an array. The chapter then concludes by replying to the shared argument that olfactory distal perception does not have the requisite res- olution to resolve the many properties problem. (shrink)

According to Smell Objectivism, the smells we perceive in olfactory experience are objective and independent of perceivers, their experiences, and their perceptual systems. Variations in how things smell to different perceivers or in different contexts raise a challenge to this view. In this paper, I offer an objectivist account of non-illusory contextual variation: cases where the same thing smells different in different contexts of perception and there is no good reason to appeal to misperception. My central example is that of (...) dihydromyrcenol, a substance that can smell both woody and citrusy depending on what other odourants one has recently been exposed to. I first argue that the subjects’ apparently conflicting reports about the way dihydromyrcenol smells are best understood as comparative characterisations of a smell. Given this understanding, different reports can be correctly made in response to perceiving the very same smell. I then argue that the phenomenal difference between the experiences subjects have across contexts can be explained compatibly with Smell Objectivism. On the account proposed, subjects perceive the very same smell but different qualities, notes, or aspects of it are salient to them, depending on the context of perception. I then consider how the proposed defence of Smell Objectivism can be adapted to other cases where the same thing is reported as smelling different in different contexts. (shrink)

While philosophers of perception develop representational theories of olfactory experiences, there are doubts regarding whether features of olfactory perception can be accommodated within the representationalist framework. In particular, it is argued that the function of olfaction is not to represent stimuli but rather to evaluate it. The paper claims that the major representational accounts of olfaction have problems in accommodating the evaluative aspects of olfactory phenomenology. However, an alternative position, named “olfactory evaluativism,” is proposed which is free of these problems (...) and may serve as a foundation for further developments of representational approach to olfactory experiences. (shrink)

We are immersed within an odorous sea of chemical currents that we parse into individual odors with complex structures. Odors have been posited as determined by the structural relation between the molecules that compose the chemical compounds and their interactions with the receptor site. But, naturally occurring smells are parsed from gaseous odor plumes. To give a comprehensive account of the nature of odors the chemosciences must account for these large distributed entities as well. We offer a focused review of (...) what is known about the perception of odor plumes for olfactory navigation and tracking, which we then connect to what is known about the role odorants play as properties of the plume in determining odor identity with respect to odor quality. We end by motivating our central claim that more research needs to be conducted on the role that odorants play within the odor plume in determining odor identity. (shrink)

Smells are often said to be ineffable, and linguistic research shows that languages like English lack a dedicated olfactory lexicon. Starting from this evidence, I propose an account of how we talk about smells in English. Our reports about the way things smell are comparative: When we say that something smells burnt or like roses, we characterise the thing's smell by noting its similarity to the characteristic smells of certain odorous things (burnt things, roses). The account explains both the strengths (...) and limitations of our smell discourse, and has implications for philosophical discussions of the relation between language and appearances. (shrink)

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 enactivism, or in terms of the similarity of content with perceptual processing. The focus of this 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. (shrink)

In the contemporary analytic discussions concerning human olfactory perception, it is commonly claimed that (1) olfactory experiences are representations having content and (2) olfactory experiences represent odours, like coffee odour or vanilla odour. However, despite these common assumptions, there seems to be an ontological controversy between two views: the first states that odours are perceptually represented as features and the second states that they are represented as objects. In this paper, I aim to systematically address the Bfeature or object^ status (...) of represented odours by concerning whether odours are represented (a) as subjects of properties, (b) as mereological wholes, and (c) entities persisting in a way characteristic for objects. I argue that olfactorily represented odours constitute a sui generis category and cannot be easily classified as objects or features. Such investigations constitute a step in establishing whether various human modalities are unified by organising the environment according to the same categories. (shrink)

The thesis that smells are objective and independent of perceivers may seem to be in tension with the phenomenon of perceptual variation. In this paper, I argue that there are principled reasons to think that perceptual variation is not a threat to objectivism about smells and is indeed integral to our perceptual relation to the objective world. I first distinguish various kinds of perceptual variation, and argue that the most challenging cases for the objectivist are those where an odourant smells (...) different in different conditions or to different perceivers but the odourant does not change, and there is neither misperception nor a simple failure to perceive a smell. I then argue that there is an independently plausible conception of olfactory experience on which even these challenging cases do not pose a threat to objectivism about smells. Following Kalderon’s work in the domain of colour perception, I argue that olfactory perception provides us with a partial perspective on the smells around us, where this perspective is constrained by the conditions of perception as well as by features of the perceiver. Within this framework, we can allow that perceivers with different sensitivities, or the same perceiver in different conditions, genuinely perceive the same objective smell even though this smell appears different to them. In turn, smells are best understood as qualitatively complex entities, different aspects of which can become perceptually available in different conditions and to different perceivers. (shrink)

According to a common opinion, human olfactory experiences are significantly different from human visual experiences. For instance, olfaction seems to have only rudimentary abilities to represent space; it is not clear whether olfactory experiences have any mereological structure; and while vision presents the world in terms of objects, it is a matter of debate whether there are olfactory object-representations. This paper argues that despite these differences visual and olfactory experiences share a hierarchical subject/property structure. Within this structure, olfactorily experienced odours (...) and visual objects have the same status: they are primary subjects which unify other represented elements into perceptual units. (shrink)

What does vision represent? What does hearing represent? Smell? Touch? Competing answers to each of these questions have been defended. The present paper argues that the issue of what taste represents is categorically more complicated. In particular, it raises two very difficult dilemmas.

This paper investigates the spatial dimensions of olfactory perception, challenging philosophical views that marginalize smell in spatial navigation and cognition compared to visual phenomenology. I argue that both olfactory and visual perceptions—despite smell often being considered non-spatial or minimally spatial—involve intricate spatial structuring when processed through unconscious cognitive processes. An information-theoretical approach shows that cognitive inferences turn spatially deficient sensory data into spatialized perceptual content to generate spatial perception across sensory modalities. This challenges the idea that spatial perception is tied (...) to external features. My argument is supported by two lines of evidence: (i) figure-ground segregation across sensory modalities, suggesting a general mechanism in perceptual processing; (ii) recent neuroscientific evidence demonstrating how spatial information is processed in olfaction for navigation and environmental mapping. My analysis calls for a reevaluation of assumptions about the non-spatial nature of smell, highlighting significant cognitive and spatial capabilities in olfaction. (shrink)

It is arguably the case that olfactory system contains two senses that share the same type of stimuli, sensory transduction mechanism, and processing centers. Yet, orthonasal and retronasal olfaction differ in their types of perceptible objects as individuated by their sensory qualities. What will be explored in this paper is how the account of orthonasal smell developed in the Molecular Structure Theory of smell can be expanded for retronasal olfaction (Young, 2016, 2019a-b, 2020). By considering the object of olfactory perception (...) to be the molecular structure of chemical compounds composing odor plumes, Molecular Structure Theory provides a means for determining an odor’s olfactory quality, how odors can be identified and individuated, and how we perceive smellscapes. Surveying the differences between orthonasal and retronasal olfaction provides the basis for the central argument of the paper that the perceptible objects we refer to as smells and individuated on the basis of their olfactory qualities are only relative to orthonasal olfaction. Retronasal olfaction it is speculatively concluded might play an essential role in our perception of flavorful objects. (shrink)

In this paper, we outline and defend a view on which in olfactory experience we can, and often do, smell ordinary things of various kinds—for instance, cookies, coffee, and cake burnings—and the olfactory properties they have. A challenge to this view are cases of smelling in the absence of the source of a smell, such as when a fishy smell lingers after the fish is gone. Such cases, many philosophers argue, show that what we perceive in olfactory experience are odour (...) objects, and not ordinary things. On behalf of our opponent, we articulate a screening-off argument based on cases of lingering smells for the thesis that we do not smell ordinary things. We then develop an alternative account of these cases that is consistent with our view. In doing so, we call into question two claims that are typically built into the notion of an odour object. (shrink)

Introduction to the topical collection "The Structure of Perceptual Objects"—with contributions by Mohan Matthen, EJ Green, Alisa Mandrigin, Blazej Skrzypulec, and Anna Drożdżowicz.

Philosophical research into olfaction often focuses on its limitations. We explore instead an underappreciated capacity of the sense of smell, namely, its role in interpersonal experience. To illustrate this, we examine how smell can enable continuing connections to deceased loved ones. Understanding this phenomenon requires an appreciation of, first, how olfaction's limitations can facilitate experiences of the deceased person and, second, how olfaction enables experiences of what we refer to as the ‘olfactory air’ of a person. This way of experiencing (...) someone privileges their status as an environmentally situated human animal. (shrink)

It is not unusual in the philosophy of perception to use empirical research to build arguments against or in favour of a certain philosophical view (see Phillips 2016 for a scrutinizing discussion). This methodology is what Barwich uses in her book entitled Smellosophy (2020) when criticizing an approach to olfaction according to which ‘truthful perception is an accurate mental representation of physical properties’ (Barwich 2020: 310). Furthermore, Barwich would like neuroscience to set the agenda for philosophical questions about olfaction, so (...) that empirical evidence is not just used to adjudicate between existing philosophical theories but instead inspires new ones, such as Barwich’s own. Thus, while her main focus is first-order theories of olfaction, she also aims to exemplify a methodology for developing and assessing such theories that ‘break[s] down the silos of institutionalized disciplinarity that are neatly dividing philosophical from neuroscientific inquiry’ (Barwich 2020: 311). The ways in which Barwich arrives at and justifies claims about olfaction give rise to various questions about the relationship between philosophical discussion of perception and neuroscientific results concerning how the brain works. In part 1 of this critical notice, I look at the approach to olfaction that Barwich criticizes and raise a few of these questions. This leads to a query about exactly how the approach differs from Barwich’s own view of olfaction. Part 2 discusses selected aspects of her view. I examine how her claim that olfaction is both exteroceptive and interoceptive and the associated idea that the brain creates odours relate to the empirical research she presents. This leads to a query concerning her methodology, which uses empirical research about brain processing to arrive at conclusions concerning a subject’s experience. (shrink)

In the contemporary analytic discussions concerning human olfactory perception, it is commonly claimed that olfactory experiences are representations having content and olfactory experiences represent odours, like coffee odour or vanilla odour. However, despite these common assumptions, there seems to be an ontological controversy between two views: the first states that odours represented by olfaction should be characterised as features and the second states that they should be interpreted as objects. In this paper, I aim to systematically address the “feature or (...) object” status of odours by comparing their ontological characteristics to those possessed by visually represented objects and features. I argue that olfactorily represented odours constitute a sui generis ontological category which differs from the categories of visually represented entities and cannot be easily classified as objects or features. Such investigations constitute a step in establishing whether various human modalities are ontologically unified by organising the environment according to the same categories. (shrink)

In this paper, I provide an account of the spatiality of olfactory experiences in terms of topological properties. I argue that thinking of olfactory experiences as making the subject aware of topological properties enables us to address popular objections against the spatiality of smells, and it makes sense of everyday spatial olfactory phenomenology better than its competitors. I argue for this latter claim on the basis of reflection on thought experiments familiar from the philosophical literature on olfaction, as well as (...) on the basis of some empirical data about the localization of smells. I conclude by suggesting how the naïve‐topology framework could be applied in debates about the spatiality of other types of experiences. (shrink)