E-Int: “Two Conceptions of Consciousness”

Two Conceptions of Consciousness
Tom Beament
4:30 p.m. 31 May 2007

http://www.informatics.sussex.ac.uk/research/groups/paics/e-int/2007-05-31.html

Approaches to understanding the nature of conscious experience can be grouped into two broad categories. Following John Campbell (Reference and Consciousness, 2002) I will refer to these approaches as “The Relational View” and “The Representational View.” The Relational View conceives of consciousness as fundamentally a matter of a relation to the world, such that: “the phenomenal content of the experience of an ordinary observer is constituted by the qualitative character of the view the observer is currently enjoying: which objects and properties are there in the scene, together with the viewpoint from which they are being observed.” (p.146) In contrast, the Representational View conceive consciousness as fundamentally a matter of having internal representational states with certain properties, such that: “the phenomenal character of your experience is constituted not by the way your surroundings are, but by the content of your representational states.” (p. 116)

Having distinguished these two conceptions of consciousness, I will briefly review the arguments presented against the Representational View by Campbell, and John McDowell (especially in “The Contents of Perceptual Experience”, 1994). These concern (the explanation of) our capacity for demonstrative thought, and the (phenomenological) correctness of a non-Cartesian view of experience. I will then outline an argument of my own against the Representational View which takes a different line, concentrating instead on the issue of the qualitative dimension of conscious experience, which has tended to be discussed in terms of the (bogus) notion of “qualia.” If this argument is successful then it represents a further blow against the Representational View. I will then suggests that some of the grounds commonly assumed to favour such a view actually provide no better support for it than there is for the Relational View. The net result is a comprehensive shifting of the burden of proof to the Representational View. Thus, in contrast to most recent work on consciousness, the Relational View of experience should be taken as the default view.

E-Int: “Some Anomalies in Memory Theory”

Some Anomalies in Memory Theory

Pasha Parpia
4:30 p.m. 24 May 2007

Given the importance of memory for both perception and cognition, it is surprising to find that current theories of learning in the nervous system appear to be in a state of discord. In this seminar, I will describe some experiments using brain imaging techniques and recordings of electrical activity, mostly in the visual and association cortices.

These experiments show that, after the onset of a stimulus, the initial activity in the primary visual cortex (V1) is followed by an efferent (descending) global signal, which modifies processing in V1. In memory experiments, these ‘top-down’ responses, which are modulated by attention, can be used to predict what will be recalled in subsequent tests. These findings support the view that perception is an active process.

However, neuroscientists investigating the molecular basis of memory do not always obtain their results from intact, awake animals. Instead, many researchers use isolated networks of cells, or anaesthetised animals. Further, computational modellers of neural networks generally ‘clamp’ inputs into their models, neglecting the role of attentional selection in learning.

In this respect, both groups of investigators ignore the dependence of learning on the motivational states of organisms. As such, results obtained from neuroscientific studies and computer simulations that neglect the ‘top-down’, global signals cannot be considered complete.

In this talk, I will also argue that the discovery of widespread synchronous neuronal firing (to within ~1 ms) in the neocortex without memory formation necessarily taking place casts doubt on Hebb’s rule. According to this rule, near-synchronous firings of pre- and post-synaptic neurons lead to the establishment of memory. The rule has been used extensively to model memory and to account for the development of cognitive functions.

E-Int: “In Search of the Concept CONCEPT”

Pevensey I 1A1

In Search of the Concept CONCEPT
Joel Parthemore
4:30 p.m. 17 May 2007

I attended a workshop this past weekend in Copenhagen, titled CONCEPTS: Content and Constitution. Peter Gardenfors, Jose Luiz Bermudez, Greg Ashby, Ruth Millikan and Daniel Dennett all presented their overlapping ideas about just what a concept is. Bermudez described concepts by contrasting them with non-conceptual content; Ashby offered a view of concepts from neuroscience, in the context of category learning; Prinz offered a spirited defense of concept empiricism (hooray! :-)); Milliken offered a teleological account of the role of “useless” concepts as a way of understanding concepts more generally; Dennett drew on the familiar analogy between source code and compiled code to, once again, contrast conceptual with non-conceptual content.

I will present all their different concepts of concept within the context of my own exploration of concept content, drawing in particular, I hope, from the talk (and recent book) by Gardenfors on conceptual spaces, and my recent work with Ron in synthetic phenomenology, as ways of using a geometry metaphor to specify the content of concepts non-conceptually. The central question I want to address is: What is our concept of concept? What, more precisely, is the content of our concept CONCEPT?

My work to date has involved examining standard and less standard theories of concepts in light of their potential applications. Building on that, I want to emphasize the centrality of an explicit and coherent theory of concepts to any work in cognitive science or AI. Further I want to argue for the importance, to any understanding of the nature of concepts, of a toggling between two perspectives: on the one hand, understanding concepts as being composed of other concepts (per e.g. Jesse Prinz and his proxytypes theory of concepts); on the other, understanding concepts as conceptually atomic (per Jerry Fodor and his informational atomism approach).* (Of course in other, non-conceptual ways, they will not be atomic at all.) Many in the field might take these perspectives to be poles apart, even incommensurable.

My intuition is that it is part of human cognition to toggle between these two perspectives constantly. When we think of concepts as concepts, then it’s natural (I want to argue) to understand them as complexly structured entities and specify their content conceptually. When we use concepts without thinking of them as concepts, then I think we need means to specify the contents of those very same concepts non-conceptually, using methods e.g. suggested by synthetic phenomenology, a term used by Ron Chrisley and others for methods of specifying the contents of experience (or certain kinds of experience) non-linguistically and indeed non-conceptually. Not only might this allow a nice continuity between non-conceptual and conceptual mental representations, it would also (I think) offer an escape from familiar self-referential paradoxes (e.g., Grelling’s Paradox)that arise when one attempts to specify the contents of concepts purely with other concepts, without needing to take the drastic step of banishing those paradoxes altogether.

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* I raised this point with Prinz after his talk. His response was just to say that Fodor is, at heart, a good empiricist! 🙂

CogPhi reading announcement

Dear all,

For the next three meetings we’ll be reading Chapter 16, ‘Philosophies of Mind as Machine’ from Maggie Boden’s book ‘Mind as Machine’, starting next Thursday with pages 1334-1362, sections 16i-16iii. You can find a copy on Ron’s door but please don’t take it for more than 30 min.

Best,
Alexander