Evan Thompson

In this thesis, I show how decisions about the ontology of colour depend upon the empirical and conceptual relations among levels of explanation for vision. In Chapter 1, I show how the "received" Lockean view of colour is linked to Newton's theory of light and colour. In Chapter 2, I review extensively recent biological, psychophysical, and computational models of colour vision, and I discuss their relations. I also show how the ontological status of colour is linked to these levels of explanation for the specific case of colour constancy. This empirical discussion provides the foundation for Chapters 3 and 4 where I argue that both objectivism and subjectivism are untenable on extensive empirical grounds. ;In Chapter 3, I argue that the computational level of explanation is not sufficient to ground an objectivist view of colour. Colour cannot be identified with surface spectral reflectance, nor can our present conception of colour be replaced by a new concept of physical colour as surface reflectance. An adequate account of colour must, then, be experientialist. I conclude this chapter by showing how arguments against objectivism are not sufficient to establish subjectivism. ;In Chapter 4, I present a novel philosophical argument based on the comparative study of colour vision in different species. This body of research has been largely neglected both by philosophers and by those who work on computational colour vision. My "comparative argument" purports to show that an adequate account of colour must be both experientialist and ecological. Whereas computational objectivism runs afoul of the experiential nature of colour, neurophysiological subjectivism runs afoul of the ecological nature of colour experience. In contrast to both objectivism and subjectivism, I defend a new view of colour, which I call ecological experientialism. According to this view, colour corresponds to a type of property that is interactional, i.e., to a type of property that results from the biological and ecological interactions of perceiving and cognizing animals. Therefore, to account for colour we must state generalizations over the ecologically embodied visual experiences of perceiving animals.

Binocular rivalry provides a useful situation for studying the relation between the temporal flow of conscious experience and the temporal dynamics of neural activity. After proposing a phenomenological framework for understanding temporal aspects of consciousness, we review experimental research on multistable perception and binocular rivalry, singling out various methodological, theoretical, and empirical aspects of this research relevant to studying the flow of experience. We then review an experimental study from our group explicitly concerned with relating the temporal dynamics of rivalrous experience to the temporal dynamics of cortical activity. Drawing attention to the importance of dealing with ongoing activity and its inherent changing nature at both phenomenological and neurodynamical levels, we argue that the notions of recurrence and variability are pertinent to understanding rivalry in particular and the flow of experience in general.

b>. Computational models of colour vision assume that the biological function of colour vision is to detect surface reflectance. Some philosophers invoke these models as a basis for 'externalism' about perceptual content (content is distal) and 'objectivism' about colour (colour is surface reflectance). In an earlier article (Thompson et al. 1992), I criticized the 'computational objectivist' position on the basis of comparative colour vision: There are fundmental differences among the colour vision of animals and these differences do not converge on the detection of any single type of environmental property. David R. Hilbert (1992) has recently defended computational objectivism against my 'comparative argument;' his arguments are based on the externalist approach to perceptual content originally developed by Mohan Matthen (1988) and on the computationally inspired theory of the evolutionary basis for trichromacy developed by Roger N. Shepard (1990). The present article provides a reply to Hilbert with extensive criticism of both Matthen's and Shepard's theories. I argue that the biological function of colour vision is not to detect surface reflectance, but to provide a set of perceptual categories that can apply to objects in a stable way in a variety of conditions. Comparative research indicates that both the perceptual categories and the distal stimuli will differ according to the animal and its visual ecology; therefore externalism and objectivism must be rejected

A renowned philosopher of the mind, also known for his groundbreaking work on Buddhism and cognitive science, Evan Thompson combines the latest neuroscience research on sleep, dreaming, and meditation with Indian and Western philosophy of the mind, casting new light on the self and its relation to the brain. Thompson shows how the self is a changing process, not a static thing. When we are awake we identify with our body, but if we let our mind wander or daydream, we project a mentally imagined self into the remembered past or anticipated future. As we fall asleep, the impression of being a bounded self distinct from the world dissolves, but the self reappears in the dream state. If we have a lucid dream, we no longer identify only with the self within the dream. Our sense of self now includes our dreaming self, the "I" as dreamer. Finally, as we meditate--either in the waking state or in a lucid dream--we can observe whatever images or thoughts arise and how we tend to identify with them as "me." We can also experience sheer awareness itself, distinct from the changing contents that make up our image of the self. Contemplative traditions say that we can learn to let go of the self, so that when we die we can witness its dissolution with equanimity. Thompson weaves together neuroscience, philosophy, and personal narrative to depict these transformations, adding uncommon depth to life's profound questions. Contemplative experience comes to illuminate scientific findings, and scientific evidence enriches the vast knowledge acquired by contemplatives

The paper presents a research programme for the neuroscience of consciousness called 'neurophenomenology' and illustrates it with a recent pilot study . At a theoretical level, neurophenomenology pursues an embodied and large-scale dynamical approach to the neurophysiology of consciousness . At a methodological level, the neurophenomenological strategy is to make rigorous and extensive use of first-person data about subjective experience as a heuristic to describe and quantify the large-scale neurodynamics of consciousness . The paper focuses on neurophenomenology in relation to three challenging methodological issues about incorporating first-person data into cognitive neuroscience: first-person reports can be biased or inaccurate; the process of generating first-person reports about an experience can modify that experience; and there is an 'explanatory gap' in our understanding of how to relate first-person, phenomenological data to third-person, biobehavioural data

Emotion experience has failed to date to gain a central place in the study of consciousness. This special issue of the _Journal of Consciousness Studies_ presents the most recent views on the matter, with discussions of several aspects of emotion experience. Contributors from different disciplines address links between feelings, brain, body and world. What happens in the brain and in the body when we have feelings? How do feelings relate to our understanding of the world? The contributors also analyse emotion experience per se — the character of moods, the role of emotion experience in demarcating the class of emotion, the alleged positive and negative character of affect, its embodied feel and its relation to action.

The enactive approach offers a distinctive view of how mental life relates to bodily activity at three levels: bodily self-regulation, sensorimotor coupling, and intersubjective interaction. This paper concentrates on the second level of sensorimotor coupling. An account is given of how the subjectively lived body and the living body of the organism are related via dynamic sensorimotor activity, and it is shown how this account helps to bridge the explanatory gap between consciousness and the brain. Arguments by O'Regan, Noë, and Myin that seek to account for the phenomenal character of perceptual consciousness in terms of ‘bodiliness’ and ‘grabbiness’ are considered. It is suggested that their account does not pay sufficient attention to two other key aspects of perceptual phenomenality: the autonomous nature of the experiencing self or agent, and the pre-reflective nature of bodily self-consciousness.

This paper sketches a phenomenological analysis of visual mental imagery and uses it to criticize representationalism and the internalist-versus-externalist framework for understanding consciousness. Contrary to internalist views of mental imagery imagery experience is not the experience of a phenomenal mental picture inspected by the mind’s eye, but rather the mental simulation of perceptual experience. Furthermore, there are experiential differences in perceiving and imagining that are not differences in the properties represented by these experiences. Therefore, externalist representationalism, which maintains that the properties of experience are the external properties represented by experience, is an inadequate account of conscious experience