A tacit assumption since the 19th Century has been that the neocortex serves as the "seat of consciousness." An unexpected challenge to that assumption arose in 1949 with the discovery that high-frequency EEG activation associated with an alert state requires the intactness of the brainstem reticular formation. This discovery became the impetus for nearly three decades of research on what came to be known as the reticular activating system. By the 1970s, however, methodological and philosophical controversies led to general abandonment (...) of subcortical theories of attention and consciousness, with a return to an almost exclusive focus upon the cortex. With recent advances in the neurosciences the focus is shifting once more, this time to the unique contributions of cortical, thalmic, and brainstem structures in mediating selective attention and perceptual awareness. This paper offers a nontechnical review of the history of these developments up to contemporary interest in the putative role of oscillatory EEG patterns in the integration of perceptual features of experience. It puts forward the thesis that a key to understanding attention and consciousness is an appreciation of contributions of the thalmus to these cognitive processes. (shrink)

Voluntary acts are preceded by electrophysiological (RPs). With spontaneous acts involving no preplanning, the main negative RP shift begins at about200 ms. Control experiments, in which a skin stimulus was timed (S), helped evaluate each subject's error in reporting the clock times for awareness of any perceived event.

I argue that, contrary to some critics, the notion of conscious experience is a good candidate for denoting a distinct and scientifically interesting phenomenon in the brain. I base this claim mainly on an analysis of neuropsychological data concerning deficits resulting from various types of brain damage as well as some additional supporting empirical evidence. These data strongly point to the hypothesis that conscious experience expresses information that is available for global, integrated, and flexible behavior.

Thomas S. Kuhn's classic book is now available with a new index.

This first volume contains discussions of the brain, methods for analyzing behavior, thought, consciousness, attention, association, time, and memory.

Starting from Marr's ideas about levels of explanation, a theory of the data structures and access processes in human memory is demonstrated on 10 tasks. Functional characteristics of human memory are captured implementation-independently. Our theory generates a multidimensional task classification subsuming existing classifications such as the distinction between tasks that are implicit versus explicit, data driven versus conceptually driven, and simple associative (two-way bindings) versus higher order (threeway bindings), providing a broad basis for new experiments. The formal language clarifies the (...) binding problem in episodic memory, the role of input pathways in both episodic and semantic (lexical) memory, the importance of the input set in episodic memory, and the ubiquitous calculation of an intersection in theories of episodic and lexical access. (shrink)

[opening paragraph] -- Clark: The `astonishing hypothesis' which you put forward in your book, and which you obviously feel is very controversial, is that `You, your joys and sorrows, your memories and ambitions, your sense of personal identity and free will are, in fact, no more than the behaviour of a vast assembly of nerve cells. As Lewis Carroll's Alice might have phrased it: `You're nothing but a pack of neurons'.' But it seems to me that this is not so (...) astonishing a statement for a scientist to make. Isn't this what reductionist science has always believed? (shrink)

A model of the neuropsychology of anxiety is proposed. The model is based in the first instance upon an analysis of the behavioural effects of the antianxiety drugs in animals. From such psychopharmacologi-cal experiments the concept of a “behavioural inhibition system” has been developed. This system responds to novel stimuli or to those associated with punishment or nonreward by inhibiting ongoing behaviour and increasing arousal and attention to the environment. It is activity in the BIS that constitutes anxiety and that (...) is reduced by antianxiety drugs. The effects of the antianxiety drugs in the brain also suggest hypotheses concerning the neural substrate of anxiety. Although the benzodiazepines and barbiturates facilitate the effects of γ-aminobutyrate, this is insufficient to explain their highly specific behavioural effects. Because of similarities between the behavioural effects of certain lesions and those of the antianxiety drugs, it is proposed that these drugs reduce anxiety by impairing the functioning of a widespread neural system including the septo-hippocampal system, the Papez circuit, the prefrontal cortex, and ascending monoaminergic and cholinergic pathways which innervate these forebrain structures. Analysis of the functions of this system suggests that it acts as a comparator: it compares predicted to actual sensory events and activates the outputs of the BIS when there is a mismatch or when the predicted event is aversive. Suggestions are made as to the functions of particular pathways within this overall brain system. The resulting theory is applied to the symptoms and treatment of anxiety in man, its relations to depression, and the personality of individuals who are susceptible to anxiety or depression. (shrink)

For three decades the writings of Jaegwon Kim have had a major influence in philosophy of mind and in metaphysics. Sixteen of his philosophical papers, together with several new postscripts, are collected in Kim [1993]. The publication of this collection prompts the present essay. After some preliminary remarks in the opening section, in Section 2 I will briefly describe Kim's philosophical 'big picture' about the relation between the mental and the physical. In Section 3 I will situate Kim's approach on (...) the larger philosophical landscape, vis-à-vis various other approaches frequently discussed in contemporary philosophy of mind. This comparative discussion will further illuminate Kim's own position, and also will serve as groundwork for subsequent discussion. In Section 4 I will point out certain persistent internal tensions in Kim's philosophical position on the mind--body problem, tensions that emerge especially clearly against the backdrop of Section 3's comparative discussion of Kim's position relative to various competing positions. In the remainder of the paper I will focus on two issues at the heart of his position, with particular attention to what he says about them in some of the more recent papers and the postscripts in Kim [1993]. First, how should a materialist understand the notion that the mental is 'determined' by the physical? More specifically, what role, if any, should be played by the concept of supervenience in explicating this kind of determination relation? Kim's views on this matter have recently changed, and I will discuss the issue with particular attention to his own latest remarks on it. This is the business of Section 5. Second, need a viable materialism assert that mentalistic psychology is reducible to neurobiology? More specifically, should a materialist insist on reducibility, despite the currently influential line of argument used by non-reductive materialists, the 'multiple realization' argument? On this matter too, Kim's views have changed somewhat; again, I will discuss the issue with particular attention to his recent thinking. This is the business of Section 6. (shrink)

Owen Flanagan argues that we are on the way to understanding consciousness and its place in the natural order.

There is considerable evidence that the hippocampal system contributes both to (1) the temporary maintenance of memories and to (2) the processing of a particular type of memory representation. The findings on amnesia suggest that these two distinguishing features of hippocampal memory processing are orthogonal. Together with anatomical and physiological data, the neuropsychological findings support a model of cortico-hippocampal interactions in which the temporal and representational properties of hippocampal memory processing are mediated separately. We propose that neocortical association areas maintain (...) shortterm memories for specific items and events prior to hippocampal processing as well as providing the final repositories of long-term memory. The parahippocampal region supports intermediate-term storage of individual items, and the hippocampal formation itself mediates an organization of memories according to relevant relationships among items. Hippocampal-cortical interactions produce (i) strong and persistent memories for events, including their constituent elements and the relationships among them, and (ii) a capacity to express memories flexibly across a wide range of circumstances. (shrink)

_Behavioral and Brain Sciences_ , 15, 183-247, 1992. Reprinted in _The Philosopher's Annual_ , Grim, Mar and Williams, eds., vol. XV-1992, 1994, pp. 23-68; Noel Sheehy and Tony Chapman, eds., _Cognitive Science_ , Vol. I, Elgar, 1995, pp.210-274.

Damasio remarks, it "informs virtually all research on mind and brain, explicitly or implicitly." Indeed, serial information processing models generally run this risk (Kinsbourne, 1985). The commentaries provide a wealth of confirming instances of the seductive power of this idea. Our sternest critics Block, Farah, Libet, and Treisman) adopt fairly standard Cartesian positions; more interesting are those commentators who take themselves to be mainly in agreement with us, but who express reservations or offer support with arguments that betray a continuing (...) allegiance to one or another tenet of the view we sought to discredit. (shrink)

Little, Brown, 1992 Review by Glenn Branch on Jul 5th 1999 Volume: 3, Number: 27.

John Searle's Speech Acts (1969) and Expression and Meaning (1979) developed a highly original and influential approach to the study of language. But behind both works lay the assumption that the philosophy of language is in the end a branch of the philosophy of the mind: speech acts are forms of human action and represent just one example of the mind's capacity to relate the human organism to the world. The present book is concerned with these biologically fundamental capacities, and, (...) though third in the sequence, in effect it provides the philosophical foundations for the other two. Intentionality is taken to be the crucial mental phenomenon, and its analysis involves wide-ranging discussions of perception, action, causation, meaning, and reference. In all these areas John Searle has original and stimulating views. He ends with a resolution of the 'mind-body' problem. (shrink)

Craik published only one complete work of any length, this essay on The Nature of Explanation.

The main idea in this series of essays is that subjective awareness depends upon the intralaminar nuclei of each thalmus. This implies that the internal structure and external relations of ILN make subjective awareness possible. An array of material relevant to this proposal was briefly reviewed in Part I. This Part II considers in more detail some semantic aspects and a bit of philosophic background as these pertain to propositions 0, 1, and 2 of Part I. Part II should be (...) read in conjunction with Part I. (shrink)

The notion of levels has been widely used in discussions of cognitive science, especially in discussions of the relation of connectionism to symbolic modeling of cognition. I argue that many of the notions of levels employed are problematic for this purpose, and develop an alternative notion grounded in the framework of mechanistic explanation. By considering the source of the analogies underlying both symbolic modeling and connectionist modeling, I argue that neither is likely to provide an adequate analysis of processes at (...) the level at which cognitive theories attempt to function: One is drawn from too low a level, the other from too high a level. If there is a distinctly cognitive level, then we still need to determine what are the basic organizational principles at that level. (shrink)

A detailed study of scientific theories of human nature and the possible ways in which human behavior can be predicted and controlled.

Investigations of the function of consciousness in human information processing have focused mainly on two questions: (1) where does consciousness enter into the information processing sequence and (2) how does conscious processing differ from preconscious and unconscious processing. Input analysis is thought to be initially "preconscious," "pre-attentive," fast, involuntary, and automatic. This is followed by "conscious," "focal-attentive" analysis which is relatively slow, voluntary, and flexible. It is thought that simple, familiar stimuli can be identified preconsciously, but conscious processing is needed (...) to identify complex, novel stimuli. Conscious processing has also been thought to be necessary for choice, learning and memory, and the organization of complex, novel responses, particularly those requiring planning, reflection, or creativity. (shrink)

Dualist and Reductionist theories of mind disagree about whether or not consciousness can be reduced to a state of or function of the brain. They assume, however, that the contents of consciousness are separate from the external physical world as-perceived. According to the present paper this assumption has no foundation either in everyday experience or in science. Drawing on evidence for perceptual projection in both interoceptive and exteroceptive sense modalities, the case is made that the physical world as-perceived is a (...) construct of perceptual processing and, therefore, part of the contents of consciousness. A finding which requires a Reflexive rather than a Dualist or Reductionist model of how consciousness relates to the brain and the physical world. The physical world as-perceived may, in turn be thought of as a biologically useful model of the world as described by physics. Redrawing the boundaries of consciousness to include the physical world as-perceived undermines the conventional separation of the 'mental' from the physical', and with it the very foundation of the Dualist-Reductionist debate. The alternative Reflexive model departs radically from current conventions, with consequences for many aspects of consciousness theory and research. Some of the consequences which bear on the internal consistency and intuitive plausibility of the model are explored, e.g. the causal sequence in perception, representationalism, a suggested resolution of the Realism versus Idealism debate, and the way manifest differences between physical events as-perceived and other conscious events are to be construed. In the present paper I wish to challenge some of our most deeply-rooted assumptions about what consciousness is, by re-examining how consciousness, the human brain, and the surrounding physical world relate to each other. (shrink)

This reply to five continuing commentaries on my 1991 target article on “Is human information processing conscious” focuses on six related issues: 1) whether focal attentive processing replaces consciousness as a causal agent in third-person viewable human information processing, 2)whether consciousness can be dissociated from human information processing, 3) continuing disputes about definitions of "consciousness" and about what constitutes a “conscious process” , 4) how observer-relativity in psychology relates (and does not relate) to relativity in physics, 5) whether the first-person (...) viewable causal efficacy of consciousness counts as ‘real’ causal efficacy and 6) a clarification of the sense in which first- and third-person causal accounts of mental processing are complementary and mutually irreducible. (shrink)

Many people have argued that the evolution of the human language faculty cannot be explained by Darwinian natural selection. Chomsky and Gould have suggested that language may have evolved as the by-product of selection for other abilities or as a consequence of as-yet unknown laws of growth and form. Others have argued that a biological specialization for grammar is incompatible with every tenet of Darwinian theory – that it shows no genetic variation, could not exist in any intermediate forms, confers (...) no selective advantage, and would require more evolutionary time and genomic space than is available. We examine these arguments and show that they depend on inaccurate assumptions about biology or language or both. Evolutionary theory offers clear criteria for when a trait should be attributed to natural selection: complex design for some function, and the absence of alternative processes capable of explaining such complexity. Human language meets these criteria: Grammar is a complex mechanism tailored to the transmission of propositional structures through a serial interface. Autonomous and arbitrary grammatical phenomena have been offered as counterexamples to the position that language is an adaptation, but this reasoning is unsound: Communication protocols depend on arbitrary conventions that are adaptive as long as they are shared. Consequently, language acquisition in the child should systematically differ from language evolution in the species, and attempts to analogize them are misleading. Reviewing other arguments and data, we conclude that there is every reason to believe that a specialization for grammar evolved by a conventional neo-Darwinian process. (shrink)

Madness and Modernism provides a phenomenological study of schizophrenic disorders, criticizing some standard conceptions of these disorders. Sass argues that many aspects of this group of disorders can actually involve more sophisticated (albeit dysfunctional) forms of mind and experience.