It is accepted that “primary awareness” may emerge from the integration of two classes of information. It is unclear, however, why this cannot take place within the comparator rather than in conjunction with feedback to the perceptual systems. The model has plausibility in relation to the continuity of conscious experience in the normal waking state and may be extended to encompass certain aspects of the “sense of self” which are frequently disrupted in psychotic patients.

I begin by tracing some of the confusions regarding levels and reduction to a failure to distinguish two different principles according to which theories can be viewed as hierarchically arranged — epistemic authority and ontological constitution. I then argue that the notion of levels relevant to the debate between symbolic and connectionist paradigms of mental activity answers to neither of these models, but is rather correlative to the hierarchy of functional decompositions of cognitive tasks characteristic of homuncular functionalism. Finally, I (...) suggest that the incommensurability of the intentional and extensional vocabularies constitutes a strongprima facie reason to conclude that there is little likelihood of filling in the story of Bechtel''s missing level in such a way as to bridge the gap between such homuncular functionalism and his own model of mechanistic explanation. (shrink)

Gray unwisely melds together two distinguishable contributions of consciousness: one to epistemology, the other to evolution. He also renders consciousness needlessly invisible behaviorally.

Gray extrapolates from circuit models of psychopathology to propose neural substrates for the contents of consciousness. I raise three concerns: knowledge of synaptic arrangements may be inadequate to fully support his model; latent inhibition deficits in schizophrenia, a focus of this and related models, are complex and deserve replication; and this conjecture omits discussion of the neuropsychological basis for the contents of the unconscious.

Prominent evolutionary psychologists have argued that our innate psychological endowment consists of numerous domainspecific cognitive resources, rather than a few domaingeneral ones. In the light of some conceptual clarification, we examine the central inprinciple arguments that evolutionary psychologists mount against domaingeneral cognition. We conclude (a) that the fundamental logic of Darwinism, as advanced within evolutionary psychology, does not entail that the innate mind consists exclusively, or even massively, of domainspecific features, and (b) that a mixed innate cognitive economy of domainspecific (...) and domaingeneral resources remains a genuine conceptual possibility. However, an examination of evolutionary psychology's 'grain problem' reveals that there is no way of establishing a principled and robust distinction between domainspecific and domaingeneral features. Nevertheless, we show that evolutionary psychologists can and do live with this grain problem without their whole enterprise being undermined. (shrink)

This commentary is divided into two parts. The first considers a possible role for Gray's predictor plus comparator mechanism in human episodic recognition memory. It draws on the computational specifications of recognition outlined in Humphreys et al. to demonstrate how the logically necessary components of recognition tasks might be mapped onto the mechanism. The second part demonstrates how the mechanism outlined by Gray might be implicated in a form of imitative learning suitable for the acquisition of complex tasks.

Gray's neuropsychological model of consciousness uses a hierarchical feedback loop framework that has been extensively discussed by many others in psychology. This commentary therefore urges Gray to integrate with, or at least acknowledge previous models. It also points out flaws in his feedback model and suggests directions for further theoretical work.

Any neurobiological model claiming explanation of a complex human phenomenon should start with an explicit definition of the explanandum. If a classical intensional definition is impossible, we can use a descriptive definition by listing necessary criteria. This commentary suggests four meta-criteria that different proposed criteria of consciousness should fulfill: phenomenological consensus, empirical evidence, domain specificity, and non-circularity.

Perspective and reflection have each been considered in some way basic to phenomenal consciousness. Each has possible evolutionary value, though neither seems sufficient for consciousness. Consider an account of consciousness in terms of the combination of perspective and reflection, its relationship to the problem of other minds, and its capacity to inherit evolutionary explanation from its components.

The commentary argues that we cannot be sure that human consciousness has survival value and that in order to understand the origins and, perhaps, the function of consciousness, we should examine the behavioural and neural precursors to consciousness in nonhumans. An example is given of research on the role of context in decisions regarding fleeing from probable predators in the Mongolian gerbil.

Gray mistakenly thinks I have rejected the sort of theoretical enterprise he is undertaking, because, according to him, I think that "more data" is all that is needed to resolve all the issues. Not at all. My stalking horse was the bizarre (often pathetic) claim that no amount of empirical, "third-person point-of-view" science (data plus theory) could ever reduce the residue of mystery about consciousness to zero. This "New Mysterianism" (Flanagan, 1991) is one that he should want to combat as (...) vigorously as I have done. (shrink)

Robust theories concerning the connection between consciousness and brain function should derive not only from empirical evidence but also from a well grounded inind-body ontology. In the case of the comparator hypothesis, Gray develops his ideas relying extensively on empirical evidence, but he bounces irresolutely among logically incompatible metaphysical theses which, in turn, leads him to excessively skeptical conclusions concerning the naturalization of consciousness.

Segmentalized consciousness in schizophrenia reflects a loss of the normal Gestalt organization and contextualization of perception. Grays model explains such segmentalization in terms of septohippocampal dysfunction, which is consistent with known neuropsychological impairment in schizophrenia. However, other considerations suggest that everyday perception and its failure in schizophrenia also involve prefrontal executive mechanisms, which are only minimally elaborated by Gray.