VOLUME 9 (1996), ISSUE 2

Discussion: Discovering the Moment of Consciousness?

VALERIE G. HARDCASTLE
Discovering the moment of consciousness? PART I: Bridging techniques at work

• Abstract: Connectionist views in psychology and neuroscience give the impression that there is no one place in the brain into which all information funnels. If these impression are accurate, then we will have great difficulty picking out a point in neuronal or psychological time at which phenomena become conscious. If so, pointing to one place in which we are conscious of a particular event and expecting a psychophysical correlation between qualitative and neural events seems hopeless. In response to this worry, I argue that ERP research can bridge the psychology and neuroscience such that we can identify when qualitative experiences occur relative to other cognitive events. I present data suggesting that accessing an early implicit priming system gives rise to a qualitatively different kind of ERP wave than does accessing a later episodic memory system. These results illustrate how it is possible to parse psychological events finely enough in (neuro-)psychological investigations in order to determine when particular psychological events occur in the head. So, if we could align consciousness with some psychological event, then we should be able to articulate when that event occurs in the processing stream (relative to other events) as long as that event can be correlated with some ERP waveform

VALERIE G. HARDCASTLE
Discovering the moment of consciousness? PART II: An ERP analysis of priming using novel visual stimuli

• Abstract: Helen Neville has gathered ERP data suggesting that accessing an "implicit" memory system produces a qualitatively different kind of ERP wave than does accessing our "explicit" conscious memory system. These results corroborate the hypothesis that an early anterior priming effect indexes activity of a system specialized for words, while a later posterior priming effect indexes access to general, episodic representations of words. Moreover, she saw no effects in the masked paradigms using pseudo-words, further supporting the notion of an early lexicon. However, we might not see any effects because the tasks use stimuli too complicated for an early automatic system to encode rapidly. Hence, masked priming effects for novel stimuli might be seen immediately with very simple input patterns. The following series of experiments was designed to test this hypothesis, as well as to try to differentiate the supposed early lexicon from other sorts of early access memory systems and to characterize more fully the capabilities of these early systems. In particular, ERP waveforms are compared for unmasked and masked priming conditions using simple 5-line visual patterns in experiments requiring subjects to make rapid decisions concerning the physical structure of the shapes.

HUIB LOOREN de JONG
Brain waves and bridges: Comments on Hardcastle's "Discovering the moment of consciousness?"

• Abstract: In this comment, a picture of ERP research is sketched that is slightly different from Hardcastle's account, in that it emphasizes the functional characterization of ERP components rather than the neurophysiological connections. It is suggested that selection pressure of ERP work on cognitive and neurophysiological theories and vice versa is a more apt metaphor for intertheoretical relations in this field than explanatory extension. Second, it is argued that the temporal characteristics of ERP components do not support Hardcastle's claim that they may be used to fix timing in phenomenal consciousness. Although I agree that ERP components, cautiously interpreted, can contribute to the identification of substages of information processing, rather than refuting Dennett and Kinsbourne, her ERP date seem compatible with a multiple drafts model.

Manuscripts:

SHAUN GALLAGHER & ANDREW N. MELTZOFF
The earliest sense of self and others: Merleau-Ponty and recent developmental studies

• Abstract: Recent studies in developmental psychology have found evidence to suggest that there exists an innate system that accounts for the possibilities of early infant imitation and the existence of phantom limbs in cases of congenital absence of limbs. These results challenge traditional assumptions about the status and development of the body schema and body image, and about the nature of the translation process between perceptual experience and motor ability. Merleau-Ponty, who was greatly influenced by his study of developmental psychology, and whose phenomenology of perception was closely tied to the concept of the body schema, accepted these traditional assumptions. They also informed his philosophical conclusions concerning the experience of self and others. We re-examine issues involved in understanding self an others in light of the more recent research in developmental psychology. More specifically our re-examination challenges a number of Merleau-Ponty's conclusions and suggest, in contrast, that the newborn infant is capable of a rudimentary differentiation between self and non-self.

MARTHA GIBSON
Asymmetric dependencies, ideal conditions, and meaning

• Abstract: Jerry Fodor has proposed a causal theory of meaning based on the notion of a certain asymmetric dependency between the causes of a symbol's tokens. This theory is held to be an improvement on Dennis Stampe's causal theory of meaning and Fred Dretske's information theoretic account, because it allegedly solves what Fodor calls the "disjunction problem", and does so without recourse to the kind of optimal (ideal) conditions to which Stampe and Dretske appeal. A series of counterexamples is proposed to Fodor's account, which, it is argued, can only be met by reintroducing that same appeal to optimal conditions that he had sought to eliminate. It is then argued that Fodor's notion of asymmetric dependence is not fundamental to the explanation of why a symbol means what it does: on the contrary, the symbol's meaning what it does is explanatorily prior to the obtaining of the asymmetry, so the asymmetry cannot be used to explain the symbol's meaning. Finally, it is argued that the "disjunction problem" as it is defined by Fodor is not a genuine problem for causal theories of meaning.

Review Essay:

PAUL A. ROTH
Review of ALVIN GOLDMAN's Liaisons: Philosophy meets the cognitive and social sciences

• Abstract: Alvin Goldman's (1992) recent collection includes many of the important and seminal contributions made by him over the last three decades to epistemology, philosophy of mind, and analytic metaphysics. Goldman is an acknowledged leader in efforts to put material from cognitive and social science to good philosophical use. This is the "liaison" which Goldman takes his own work to exemplify and advance. Yet the essays contained in Liaisons chart an important evolution in Goldman's own views about the relation between philosophy and empirical inquiry. Goldman raises, if only unwittingly, the question of what philosophy per se contributes to the encounter. The way in which Goldman's work problematizes the claim that philosophy forms a working liaison with the cognitive and social sciences is revealed by examining two sets of distinctions prominent in Goldman's analyses in this volume. I trace how each pair of terms—philosophy versus science, individual versus social—is used by Goldman and suggest that it is less clear than one would like how these key notions are or could be distinguished from one another. Doubts about these distinctions, at least as Goldman employs them, suggest more general concerns regarding Goldman's style of naturalism and the status of philosophy as a source of knowledge.

Book Reviews:

DAVID C. GEARY
Review of J.T. BRUER's Schools for thought: A science of learning in the classroom

BERT H. HODGES
Review of ULRIC NEISSER's The perceived self: Ecological and interpersonal sources of self-knowledge

ROBERT SCHWARTZ
Review of AARON BEN-ZE'EV's The perceptual system: A philosophical and psychological perspective

DEBRA SUE PATE
Review of D. ALFRED OWENS & MARK WAGNER's Progress in modern psychology: The legacy of American functionalism

TRACY B. HENLEY
Review of MARGARET E. DONNELLY's Reinterpreting the legacy of William James