Carrion and dung odours of various flowers have traditionally been considered an adaptation for attracting the flies and beetles that pollinate them. While we accept the role of such odours in pollinator attraction, we propose that they may also have another, overlooked, anti‐herbivore defensive function. We suggest that such odours may deter mammalian herbivores, especially during the critical period of flowering. Carrion odour is a good predictor for two potential dangers to mammalian herbivores: (1) pathogenic microbes, (2) proximity of (...) carnivores. Similarly, dung odour predicts faeces‐contaminated habitats that present high risks of parasitism. These are two new types of repulsive olfactory aposematic mimicry by plants: (1) olfactory feigning of carcass (thanatosis), a well‐known behavioural defensive strategy in animals, (2) olfactory mimicry of faeces, which also has a defensive visual parallel in animals. (shrink)

The adverse effects of the Covid-19 pandemic have exposed the lack of multi-scalar community resilient strategies that catalyze the development of alternative coping mechanisms for future challenges. To address the immediate needs of vulnerable and marginalized groups, especially in times of crisis, as evidenced by the pandemic, micro-networks within communities have mitigated and reduced harm through self-devised ingenuity based on local ways of life. Socio-spatial micro-networks have the potential to empower communities to self-organize, engage, collaborate, co-design, co-build, and connect with (...) other communities to improve their resilience. This paper focuses on the impact of micro-networks of care, participatory action research, community health, solidarity and mutual aid in Nairobi (Kenya), comparing their resilience strategies, pre- and post Covid-19 pandemic era. Through analytical, empirical, and comparative studies, this paper envisions viable ways of augmenting and enhancing self-devised, self-sufficient, and resilient culture in marginalized communities in Africa and worldwide. -/- . (shrink)

The evolutionary advantage of psychological phenomena can be gleaned by comparing them with physical traits that have proven adaptive in other organisms. The present article provides a novel evolutionary explanation of suicide in humans by comparing it with aposematism in insects. Aposematic insects are brightly colored, making them conspicuous to predators. However, such insects are equipped with toxins that cause a noxious reaction when eaten. Thus, the death of a few insects conditions predators to avoid other insects of similar (...) coloration. Analogously, human suicides may increase the credibility of future suicide threats and attempts from others, conveying an evolutionary advantage to the phenotypic expression of suicidal behavior in low-fitness contexts. (shrink)

It is natural to think that sight is distinctive amongst the senses in that we typically see ordinary objects directly, rather than seeing a visual equivalent to a sound or odour. It is also natural to think that sounds and odours (like rainbows and holograms) are sensibilia, in that they are each intimately related to just one of our senses. In this chapter, I defend these natural-seeming claims. I present a view on which odours are indeed sensibilia, a claim (...) that is in need of defence when confronted with the suggestion that they are clouds of molecules. Furthermore, I argue that odours and rainbows, whilst both sensibilia, differ in ways that reflect their different roles for perceivers. (shrink)

This chapter argues that smell and flavour perception present distinctive challenges for phenomenological reflection, but that these difficulties can be addressed through a ‘gestaltist’ approach to perceptual organisation. I argue that the ‘chemical’ senses do not generally allow immediate access to ordinary objects like roses and apples, but rather to odours and flavours, the diffuse nature of which make it hard to get a grip on the associated perceptual phenomenology. Drawing on the work of gestalt psychologists and phenomenologists, I outline (...) a modality-neutral approach that emphasises the irreducibly structured nature of perceptual experience and is especially useful for thinking about experiences that are not targeted at ordinary physical objects. Such an approach can clarify and explain nebulous aspects of perceptual experience, illuminating elements of our smell and flavour experiences that may be indeterminate. (shrink)

The sense of smell occupies a peculiar intermediate position within Aristotle's theory of sense perception: odours, like colours and sounds, are perceived at a distance through an external medium of air or water; yet in their nature they are intimately related to flavours, the proper objects of taste, which for Aristotle is a form of touch. In this paper, I examine Aristotle's claims about odour and smell, especially in De Anima II.9 and De Sensu 5, to see what light (...) they shed on his theory of sense perception more generally. In the first half, I argue that neither of the two most influential recent ways of understanding Aristotle's theory of perception can adequately account for what he says about the sense of smell. In the second half, I offer my own positive account, considering and resolving various puzzles raised by Aristotle's claims about the nature of odour and its relation to flavour. Finally, I conclude that Aristotle's discussions of odour and smell suggest a plausible and interesting way of understanding the relationship, on his view, between ordinary, material changes in the sense organs and the activation of the capacity to perceive, considered merely as such. (shrink)

Collective memory, social memory, professional memory: although these notions are in current use when we name the shared (or assumed to be shared) representations of the past, they are very ambiguous. The point at issue is to show how memories can become common to some or to all members of a group . In this paper, I shall base my arguments on the simplest situation imaginable: The sharing of a memory of an olfactory experience by two individuals, namely one of (...) my informants – a gravedigger – and myself. We can try to explain this shared olfactory memory, or the imagination of this sharing, by taking two facets into consideration. First of all, we must learn to take seriously those few seconds when a shared experience of the sensory world took shape between the anthropologist and his informant. Secondly, we must attempt to answer both of the following questions: what is the nature of this sharing? And what conditions make it possible? In the first part of this text, I examine the issue of the nature of sharing by weighing up its aspects as I consider protomemory, memory and metamemory. In the second part, I outline one of the essential conditions of sharing: the existence of what I call sociotransmitters. For the most part, my attention remains focused on that particular moment when the gravedigger said, “Smell this!” , and when what was at stake was to save the interaction. (shrink)

Christianism often mentions perfumes. Its liturgy based on Scripture uses incense and balm. A reading from the Bible and the lives of saints reveals many extraordinary perfumes (“odours of sanctity”). The Virgin Mary holds extreme importance among saints and it is quite common to see her spreading miraculous fragrances. These are subtle, discrete but pleasant signals from Heaven. They are sent to everyone in order to convert non‑believers or turn back believers to the faith in God. The divine origin of (...) perfumes is tied up with the memories and hopes from Paradise. It marks bodies escaping from death and entering into eternal life. (shrink)

Odour-sound correspondences provide some of the most fascinating and intriguing examples of crossmodal associations, in part, because it is unclear from where exactly they originate. Although frequently used as similes, or figures of speech, in both literature and poetry, such smell-sound correspondences have recently started to attract the attention of experimental researchers too. To date, the findings clearly demonstrate that the majority of non-synaesthetic individuals associate orthonasally-presented odours with various different sound properties, e.g., pitch, instrument type, and timbre, in (...) a non-random manner. What is more, these auditory-olfactory associations exhibit a number of features that are common to other crossmodal associations, such as their consistency over time, and their bidirectionality. However, the psychological mechanism underpinning these associations in the general population remain unclear, with a number of distinct hypotheses having been put forward over the years. In this chapter, we consider auditory-olfactory associations in art and science, focusing on poetry, music composition, and performance. First, we provide examples of the use of auditory-olfactory synaesthetic metaphors in poetry, from William Shakespeare through to Romanticism, illustrating how crossmodal associations have appeared in literature for centuries. Then, we move on to focus on music composition and performance, describing a number of examples where auditory stimuli have been purposely matched with crossmodally corresponding olfactory and/or visual stimuli. Considering the scientific study of smell-sound correspondences, we review the key psychophysical studies demonstrating that, beyond the artistic context, robust and non-random crossmodal associations are also triggered in the majority of the general population. We discuss a number of hypotheses that have been put forward over the years to account for such associations, focusing on the idea that certain correspondences between olfactory and auditory stimuli are mediated by the emotional character of the component stimuli. (shrink)

Acoustic signals serving intraspecific communication by predators are perceived by potential prey as warning signals. We analysed the acoustic characteristics of howling of wolves and found a striking similarity to the warning sounds of technical sirens. We hypothesize that the effectivity of sirens as warning signals has been enhanced by natural sensory predisposition of humans to get alerted by howling of wolves, with which they have a long history of coexistence. Psychoacoustic similarity of both stimuli seems to be supported by (...) the fact that wolves and dogs perceive the sound of technical sirens as a relevant releasing supernormal stimulus and reply to it with howling. Inspiration by naturally occurring acoustic aposematic signals might become an interesting example of biomimetics in designing new warning sound systems. (shrink)

The peak-end rule predicts that retrospective evaluations of affective events heavily depend on their most intense and last moment and imply duration neglect. It was originally proposed for negativ...

Forensic science and its influence on policing and the criminal justice system have increased since the beginning of the twentieth century. While the philosophies of the forensic science pioneers remain the pillar of modern practice, rapid advances in technology and the underpinning sciences have seen an explosion in the number of disciplines and tools. Consequently, the way in which we exploit and interpret the remnant of criminal activity are adapting to this changing environment. In order to best exploit the trace, (...) an interdisciplinary approach to both research and investigation is required. In this paper, nine postdoctoral research fellows from a multidisciplinary team discuss their vision for the future of forensic science at the crime scene, in the laboratory and beyond. This paper does not pretend to be exhaustive of all fields of forensic science, but describes a portion of the postdoctoral fellows’ interests and skills. (shrink)

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)

William S. Robinson has for many years written insightfully about the mind-body problem. In Understanding Phenomenal Consciousness he focuses on sensory experience and perception qualities such as colours, sounds and odours to present a dualistic view of the mind, called Qualitative Event Realism, that goes against the dominant materialist views. This theory is relevant to the development of a science of consciousness which is now being pursued not only by philosophers but by researchers in psychology and the brain sciences. This (...) provocative book will interest students and professionals who work in the philosophy of mind and will also have cross-disciplinary appeal in cognitive psychology and the brain sciences. (shrink)

Humans are poorer at identifying smells and communicating about them, compared to othersensory domains. They also cannot easily organise odour sensations in a general conceptual space like with colours. We challenge the conclusion that there is no olfactory conceptual map at all. Instead we propose a new framework, with local conceptual spaces.

The act of killing self contradicts the central purpose of human evolution, that is, survival and propagation of one’s genetic material. Yet, it continues to be one of the leading causes of human death. A handful of theories in the realm of evolutionary psychology have attempted to explain human suicide. The current article analyses the major components of certain prominent viewpoints, namely, Inclusive fitness, Bargaining model, Pain-Brain model, Psychological aposematism, and few other perspectives. The article argues that relatively more weightage (...) has been given to understanding ultimate (the “why”) rather than proximate (the “how”) functionality of suicidal acts. Evolutionary theorists have consistently pointed out that to comprehensively understand a trait or behavior, one needs to delineate not only how it supports survival but also the evolution of the mechanisms underlying the trait or behavior. Existing theories on suicide have primarily focused on its fitness benefits on surviving kin instead of providing evolutionary explanations of the more complex mechanisms leading up to such self-destructive motivations. Thus, the current paper attempts to highlight this gap in theorizing while suggesting probable proximate explanations of suicide which stresses the need to diffuse attention paid to fitness consequences of the act alone. We speculate that such explorations are needed in order to build a robust and comprehensive evolutionary theory of human suicide. (shrink)

The question of whether we can perceive absences, in addition to ‘positives’, has received recent attention in the literature on the nature of vision and audition. The aim is to demonstrate that there can be objectless forms of perceptual consciousness; specifically, to show that such episodes can be distinguished from those in which there is merely no perception at all. The current article explores this question for the domain of olfaction, and argues that there can be experiences of the absence (...) of odours, in addition to positive smell perception. Doing so sheds light upon the structure and spatial content of olfaction. (shrink)

Objects are central to perception and our interactions with the world. We perceive the world as parsed into discrete entities that instantiate particular properties, and these items capture our attention and shape how we interact with the environment. Recently there has been some debate about whether the sense of smell allows us to perceive odours as discrete objects, with some suggesting that olfaction is aspatial and doesn’t allow for object-individuation. This paper offers two empirically tractable criteria for assessing whether particular (...) objects are exhibited in perceptual experience— susceptibility to figure-ground segregation and perceptual constancies—and argues that these criteria are fulfilled by olfactory perception, and thus there are olfactory objects. I argue that there are, in fact, two different ways that olfaction allows for figure-ground segregation. First, I look at various Gestalt grouping principles, which are thought to govern when features are perceived as grouped into structured wholes, segregated from everything around them. I argue that these principles apply to olfactory experience, providing evidence of non-spatial figure-ground segregation. Second, I defend the contentious idea that a spatial variety of figure-ground segregation can also occur in olfaction. To see this, however, we need to look to empirical evidence showing that tactile stimulation and bodily movements play a crucial role in olfactory phenomenology. Finally, I draw on empirical evidence and olfactory phenomenology to argue that there are perceptual constancies in olfactory experience, allowing us to perceive odours as coherent objects that survive shifts in our perspectives on the world. (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)

Many individuals on the autism spectrum are hypersensitive to certain sensory stimuli. For this group, as well as for non-autistic individuals with sensory processing disorders, being exposed to e.g. fluorescent lights, perfume odours, and various sounds and noises can be real torment. In this article, I consider the normative implications of such offence for the design of office spaces, which is a topic that has not received any attention from philosophers. After identifying different ways in which the senses of hypersensitive (...) workers might be protected within these spaces, I show that many of such accommodations can be made at reasonable cost, before arguing that doing so ought to be a legal requirement. (shrink)

Dogs are known for their incredible ability to detect odours, extracting them from a “complex” environment and recognising them. This makes sniffer dogs precious assets in a broad variety of security applications. However, their use is subject to some intrinsic restrictions. Dogs can only be trained to a limited set of applications, get tired after a relatively short period, and thus require a high turnover. This has sparked a drive over the past decade to develop artificial sniffer devices—generally known as (...) “chemical sniffers” or “electronic noses”—able to complement and possibly replace dogs for some security applications. Such devices have been already deployed, or are intended to be deployed, at borders, airports and other critical installation security checkpoints. Similarly to dogs, they are adopted for detecting residual traces that indicate either the presence of, or recent contact with, substances like drugs and explosives. It goes without saying that, as with sniffer dogs, the use of artificial sniffer devices raises many sensitive issues. Adopting an ethical and legal perspective, the present paper discusses the privacy and data protection implications of the possible deployment of a hand-held body scanning sniffer for screening passengers at EU airport security checkpoints. (shrink)

Appearance of Old world vipers of genus Vipera serves various purposes including crypsis and aposematism. Recent research showed that the zigzag pattern represents strong signal to predators to avoid vipers as a prey. It is also possible that vipers function within ecological community as Batesian model for numerous mimics, including other reptiles, birds, and invertebrates. It is then showed that Batesian models need to have prominent features to sustain the mimicry system. The main modulation of this system is presented here (...) as iconicity. Iconicity is treated as quantitative variable resulting from open dynamic process with multiple inputs, also including iconicity of previous states of system. Batesian mimicry is based on mimics adopting the iconicity of the model. It is an example of ecological facilitation, and as such, it is part of niche construction. Since Batesian mimicry is based on semiotic processes, it is a special case of ecological facilitation, namely semiotic facilitation. (shrink)

Several studies have reported impairment in the recognition of facial expressions of disgust in patients with Huntington's disease (HD) and preclinical carriers of the HD gene. The aim of this study was to establish whether impairment for disgust in HD patients extended to include the ability to express the emotion on their own faces. Eleven patients with HD, and 11 age and education matched healthy controls participated in three tasks concerned with the expression of emotions. One task assessed the spontaneous (...) production of disgust-like facial expressions during the smelling of offensive odorants. A second assessed the production of posed facial expressions during deliberate attempts to communicate emotion. The third task evaluated HD patients’ ability to imitate the specific facial configurations associated with each emotion. Foul odours induced fewer disgust-like facial reactions in HD patients than in controls, and patients’ posed facial expressions of disgust were less accurate than the posed disgust expressions of controls. The effect was selective to disgust; patients had no difficulty posing expressions of other emotions. These impairments were not explained by compromised muscle control: HD patients had no difficulty imitating the facial movements required to display disgust. Viewed together with evidence of difficulty in other aspects of disgust in HD, the findings suggest that a common substrate might participate in both the processing and the expression of this emotion. (shrink)

Anosmia, or the absence of smell, is not just a subjective experience but, as I argue in this text, an ontological affect. Anosmia in the form of deodorisation and hygienisation, is the aim for many institutions, indeed often societies as a whole, that try to direct individual affects along prefabricated targets of racial, ethnic and class discrimination, rampant consumerism and unconscious participation in atmospheric engineering. Odours consist of what I would like to call the olflow, the incessant flow of odours (...) in which human and nonhuman bodies are agents of odour generation and consumption. Odour engineering directs the olflow and reinforces olfactory discrimination. I conclude with a call against the threat of what I call ‘ontological anosmia’, namely the flattening of multiplicity of desire and the engineering of emergence as spontaneity. (shrink)

Drawing heavily upon natural history data from the Neotropical butterfly fauna, an attempt is made to develop a model, with testable hypotheses, to account for the evolution of egg-clustering and larval gregariousness. Given the high diversity of both plant and butterfly species in the American tropics, there is a higher incidence of egg-clustering there, including some species with aposematically-colored immature stages. Emphasis is placed on the need to examine both the physical (mechanical) toughness of larval food plants for larval feeding (...) success, and the spatial structuring of food plant populations. It is argued that when food plant spatial patchiness is high, the breadth of local food plant species usage low, plant growth rates high, fed-upon structures tough, butterfly dispersal low, and reproductive potential low, egg-clustering evolves. Such ecological character states, coupled with the occurrence of food plant patches in large sizes relative to the nutritional and fecundity needs of the butterfly specialist on the species, select for egg-clustering to ensure survival of the butterfly population in that habitat. It is emphasized that the model proposed here requires considerable examination through field studies. (shrink)

This work proposes a coevolutionary theory of aesthetics that encompasses both biotic and human arts. Anthropocentric perspectives in aesthetics prevent the recognition of the ontological complexity of the aesthetics of nature, and the aesthetic agency of many non-human organisms. The process of evaluative coevolution is shared by all biotic advertisements. I propose that art consists of a form of communication that coevolves with its own evaluation. Art and art history are population phenomena. I expand Arthur Danto’s Artworld concept to any (...) aesthetic population of producers and evaluators. Current concepts of art cannot exclusively circumscribe the human arts from many forms of non-human biotic art. Without assuming an arbitrarily anthropocentric perspective, any concept of art will need to engage with biodiversity, and either recognize many instances of biotic advertisements as art, or exclude some instances of human art. Coevolutionary aesthetic theory provides a heuristic account of aesthetic change in both human and biotic artworlds, including the coevolutionary origin of aesthetic properties and aesthetic value within artworlds. Restructuring aesthetics, art criticism, and art history without human beings at the organizing centers of these disciplines stimulate new progress in our understanding of art, and the unique human contributions to aesthetics and aesthetic diversity. (shrink)

“I can smell you”—spoken as a factive statement, it is jarring and if uttered to a stranger it seems transgressive. Telling someone you see them generates a sense of affirming their identity, but your smell is private. Perhaps smell isn’t the lead sense, but what I hope to make clear throughout this chapter is that our sense of smell allows us to perceive aspects of our own and other’s identity. The chapter aims to show that our unconscious perception of the (...) smell of ourselves and others partially constitutes the foundations for our sense of self. We are immersed within an invisible sea of odourous chemical currents, some derived from our environment with its everyday flux of objects while other odourous plumes derive from the humanity encompassing us. People have a rich bouquet of smells generated from the volatile chemical compounds emanating from them, including their bodily odours (BO), their adorned perfumes, and associated environmental smells from their abode hitchhiking on their person. As individuals we have a smell that is composed from these ranges of odours that allows us to recognize ourselves as an olfactory entity distinct from someone else’s BO bouquet. However, if forced to introspectively report our own smell we would be befuddled. We aren’t often aware of smelling ourselves (unless we are worried about stinking), and we have trouble recollecting the last time we volitionally engaged in exploratorily sniffing someone else. Thus, establishing a weak constitution relation between smelling and our sense of self is challenging. What will need to be revealed is something that escapes our daily awareness and introspective access, that is, that we are continually perceiving our own and other people’s smells. Moreover, these qualitative states occur outside of conscious awareness and yet generate an underlying aspect of our sense of self. Aside from jostling our intuitions about the foundations of our sense of self the evidence surveyed might also require reconceptualizing the conscious versus unconscious distinction in accommodating the nature of our olfactory self and other smelling. (shrink)

Honeybees show lateral asymmetry in both learning about odours associated with reward and recalling memory of these associations. We have extended this research to show that bees exhibit lateral biases in their initial response to odours: viz., turning towards the source of an odour presented on their right side and turning away from it when presented on their left side. The odours we presented were the main component of the alarm pheromone, iso-amyl acetate (IAA), and four floral scents. The (...) significant bias to turn towards IAA odour on the right and away from it on the left is, we argue, a lateralization of the fight-flight response elicited by this pheromone. It contrasts to an absence of any asymmetry in the turning response to an odour of the flowers on which the bees had been feeding prior to testing: to this odour they turned towards when it was presented on either the left or right side. Lemon and orange odours were responded to differently on the left and right sides (towards on the right, away on the left) but no asymmetry was found in responses to rose odour. Our results show that side biases are present even in the initial, orienting response of bees to certain odours. (shrink)

This seminal paper, which marks a turning point of the chemical revolution, is presented for the first time in a complete English translation. In this first half Lavoisier undermines phlogiston chemistry by arguing that his French contemporaries had replaced Stahl’s original theory with radically different systems that conceptualised the phlogiston principle in completely incompatible ways. He refutes their claims by showing that these later models were riddled with inconsistencies as to phlogiston’s weight, its ability to penetrate glass and its role (...) as a source of colour and odour in chemical compounds. (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 (...) class='Hi'>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)

Locke was once supposed to have argued that since the colours, sounds, odours, and other ‘secondary’ qualities things appear to have can vary greatly according to the state and position of the observer, it follows that our ideas of the ‘secondary’ qualities of things do not ‘resemble’ anything existing in the objects themselves. And Berkeley has been credited with the obvious objection that similar facts about the ‘relativity’ of our perception of ‘primary’ qualities show that they do not ‘resemble’ anything (...) existing in the objects either, so that both ‘primary’ and ‘secondary’ qualities exist only ‘in the mind’. The falsity of this view of Locke has been amply demonstrated in recent years, but no corresponding revision has been made in what remains the standard interpretation of Berkeley's criticisms of Locke. His objections therefore appear to be based on misunderstanding and to be irrelevant to what is now seen to be Locke's actual view and his reasons for holding it. I think this account of Berkeley, like the old view of Locke, is a purely fictional chapter in the history of philosophy, and in this paper I try to show that Berkeley's criticisms involve no misunderstanding and amount to a direct denial of the view Locke actually held. (shrink)

Deciphering the neural basis of subjective experience remains one of the great challenges in the natural sciences. The structural complexity and the limitations around invasive experimental manipulations of the human brain have impeded progress towards this goal. While animals cannot directly report first-person subjective experiences, their ability to exhibit flexible behaviours such as motivational trade-offs are generally considered evidence of sentience. The worm _Caenorhabditis elegans_ affords the unique opportunity to describe the circuitry underlying subjective experience at a single cell level (...) as its whole neural connectome is known and moreover, these animals exhibit motivational trade-offs. We started with the premise that these worms were sentient and then sought to understand the neurons that were both necessary and sufficient for a motivational trade-off involving the rewarding experience of food and the negative experience of an aversive odour. A simple hierarchical network consisting of two chemosensory neurons and three interneurons was found to produce an output to motoneurons that enabled worms to respond in a contextually appropriate manner to an aversive odour according to the worm's hunger state. Given that this circuitry is like that found in the human spinal cord, retina, and primary visual cortex, three regions which are neither necessary nor sufficient for subjective experience, we conclude that motivational trade-offs are not a criterion for subjective experience in worms. Furthermore, once the neural substrate for a behaviour is described, we question the explanatory role of subjective experience in behaviour. (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)

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)

Chaos theory is a rapidly growing field. As a technical term, chaos refers to deterministic but unpredictable processes being sensitively dependent upon initial conditions. Neurobiological models and experimental results are very complicated and some research groups have tried to pursue the neuronal chaos. Babloyantz's group has studied the fractal dimension (d) of electroencephalograms (EEG) in various physiological and pathological states. From deep sleep (d=4) to full awakening (d>8), a hierarchy of strange attractors paralles the hierarchy of states of consciousness. In (...) epilepsy (petit mal), despite the turbulent aspect of a seizure, the attractor dimension was near to 2. In Creutzfeld-Jacob disease, the regular EEG activity corresponded to an attractor dimension less than the one measured in deep sleep. Is it healthy to be chaotic? An active desynchronisation could be favourable to a physiological system. Rapp's group reported variations of fractal dimension according to particular tasks. During a mental arithmetic task, this dimension increased. In another task, a P300 fractal index decreased when a target was identified. It is clear that the EEG is not representing noise. Its underlying dynamics depends on only a few degrees of freedom despite yet it is difficult to compute accurately the relevant parameters.What is the cognitive role of such a chaotic dynamics? Freeman has studied the olfactory bulb in rabbits and rats for 15 years. Multi-electrode recordings of a few mm2 showed a chaotic hierarchy from deep anaesthesia to alert state. When an animal identified a previously learned odour, the fractal dimension of the dynamics dropped off (near limit cycles). The chaotic activity corresponding to an alert-and-waiting state seems to be a field of all possibilities and a focused activity corresponds to a reduction of the attractor in state space. For a couple of years, Freeman has developed a model of the olfactory bulb-cortex system. The behaviour of the simple model without learning was quite similar to the real behaviour and a model with learning is developed. (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)

ABSTRACTThe olfactory system provides us with rich information about the world, but the odours around us are not always detectable. Previous research has shown that disgust enhances olfactory sensi...