Some birds display behavior reminiscent of the sophisticated cognition and higher levels of consciousness usually associated with mammals, including the ability to fashion tools and to learn vocal ...sequences. It is thus important to ask what neuroanatomical attributes these taxonomic classes have in common and whether there are nevertheless significant differences. While the underlying brain structures of birds and mammals are remarkably similar in many respects, including high brain-body ratios and many aspects of brain circuitry, the architectural arrangements of neurons, particularly in the pallium, show marked dissimilarity. The neural substrate for complex cognitive functions that are associated with higher-level consciousness in mammals and birds alike may thus be based on patterns of circuitry rather than on local architectural constraints. In contrast, the corresponding circuits in reptiles are substantially less elaborated, with some components actually lacking, and in amphibian brains, the major thalamopallial circuits involving sensory relay nuclei are conspicuously absent. On the basis of these criteria, the potential for higher-level consciousness in these taxa appears to be lower than in birds and mammals.
Biophysics is an evolving, multidisciplinary subject which applies physics to biological systems and promotes an understanding of their physical properties and behaviour. Biophysics: An Introduction, ...is a concise balanced introduction to this subject. Written in an accessible and readable style, the book takes a fresh, modern approach with the author successfully combining key concepts and theory with relevant applications and examples drawn from the field as a whole. Beginning with a brief introduction to the origins of biophysics, the book takes the reader through successive levels of complexity, from atoms to molecules, structures, systems and ultimately to the behaviour of organisms. The book also includes extensive coverage of biopolymers, biomembranes, biological energy, and nervous systems. The text not only explores basic ideas, but also discusses recent developments, such as protein folding, DNA/RNA conformations, molecular motors, optical tweezers and the biological origins of consciousness and intelligence. Biophysics: An Introduction* Is a carefully structured introduction to biological and medical physics * Provides exercises at the end of each chapter to encourage student understanding Assuming little biological or medical knowledge, this book is invaluable to undergraduate students in physics, biophysics and medical physics. The book is also useful for graduate students and researchers looking for a broad introduction to the subject.
Exploitation of an unconscious veto mechanism, mediated by a specific cortical circuit, and made possible by an adequate very-short-term memory span, paradoxically requires conscious awareness. Part ...of the same circuit, interacting with other brain components, permits internal simulations of the body's interactions with the environment, thereby providing the basis of mind.
*) Presented on 21 August 1997 at the Brain & Self Workshop, Helsingør, Denmark.
Exploitation of an unconscious veto mechanism, mediated by a specific cortical circuit, and made possible by an adequate very-short-term memory span, paradoxically requires conscious awareness. Part of the same circuit, interacting with other brain components, permits internal simulations of the body's interactions with the environment, thereby providing the basis of mind.
*) Presented on 21 August 1997 at the Brain & Self Workshop, Helsingør, Denmark.
Exploitation of an unconscious veto mechanism, mediated by a specific cortical circuit, and made possible by an adequate very-short-term memory span, paradoxically requires conscious awareness. Part ...of the same circuit, interacting with other brain components, permits internal simulations of the body's interactions with the environment, thereby providing the basis of mind.
*) Presented on 21 August 1997 at the Brain & Self Workshop, Helsingør, Denmark.
It is suggested that the anatomical structures which mediate consciousness evolved as decisive embellishments to a (non-conscious) design strategy present even in the simplest unicellular organisms. ...Consciousness is thus not the pinnacle of a hierarchy whose base is the primitive reflex, because reflexes require a nervous system, which the single-celled creature does not possess. By postulating that consciousness is intimately connected to self-paced probing of the environment, also prominent in prokaryotic behavior, one can make mammalian neuroanatomy amenable to dramatically straightforward rationalization. Muscular contraction is the nervous system's only externally directed product, and the signaling routes which pass through the various brain components must ultimately converge on the motor areas. The function of several components is still debatable, so it might seem premature to analyze the global operation of the circuit these routes constitute. But such analysis produces a remarkably simple picture, and it sheds new light on the roles of the individual components. The underlying principle is conditionally permitted movement, some components being able to veto muscular contraction by denying the motor areas sufficient activation. This is true of the basal ganglia (BG) and the cerebellum (Cb), which act in tandem with the sensory cerebrum, and which can prevent the latter's signals to the motor areas from exceeding the threshold for overt movement. It is also true of the anterior cingulate, which appears to play a major role in directing attention. In mammals, the result can be mere thought, provided that a second lower threshold is exceeded. The veto functions of the BG and the Cb stem from inhibition, but the countermanding disinhibition develops at markedly different rates in those two key components. It develops rapidly in the BG, control being exercised by the amygdala, which itself is governed by various other brain regions. It develops over time in the Cb, thereby permitting previously executed movements that have proved advantageous. If cognition is linked to overt or covert movement, intelligence becomes the ability to consolidate individual motor elements into more complex patterns, and creativity is the outcome of a race-to-threshold process which centers on the motor areas. Amongst the ramifications of these ideas are aspects of cortical oscillations, phantom limb sensations, amyotrophic lateral sclerosis (ALS) the difficulty of self-tickling and mirror neurons.
Men, Minds, and Machines Cotterill, Rodney M. J.; Dupuy, Jean-Pierre; DeBevoise, Malcolm B.
The American Journal of Psychology,
03/2003, Letnik:
116, Številka:
1
Book Review, Journal Article
Recenzirano
Cotterill reviews "The Mechanization of the Mind: On the Origins of Cognitive Science" by Jean-Pierre Dupuy and translated by Malcolm B. DeBevoise.
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