Computational properties of use of biological organisms or to the construction of computers can emerge as collective properties of systems having a large number of simple equivalent components (or neurons). The physical meaning of content-addressable memory is described by an appropriate phase space flow of the state of a system. A model of such a system is given, based on aspects of neurobiology but readily adapted to integrated circuits. The collective properties of this model produce a content-addressable memory which correctly yields an entire memory from any subpart of sufficient size. The algorithm for the time evolution of the state of the system is based on asynchronous parallel processing. Additional emergent collective properties include some capacity for generalization, familiarity recognition, categorization, error correction, and time sequence retention. The collective properties are only weakly sensitive to details of the modeling or the failure of individual devices.

https://www.pnas.org/content/pnas/79/8/2554.full.pdf

Neural networks and physical systems with emergent collective computational abilities

So far in this course we have dealt entirely with the evolution of characters that are controlled by simple Mendelian inheritance at a single locus. There are notes on the course website about gametic disequilibrium and how allele frequencies change at two loci simultaneously, but we didn’t discuss them. In every example we’ve considered we’ve imagined that we could understand something about evolution by examining the evolution of a single gene. That’s the domain of classical population genetics. For the next few weeks we’re going to be exploring a field that’s actually older than classical population genetics, although the approach we’ll be taking to it involves the use of population genetic machinery. If you know a little about the history of evolutionary biology, you may know that after the rediscovery of Mendel’s work in 1900 there was a heated debate between the “biometricians” (e.g., Galton and Pearson) and the “Mendelians” (e.g., de Vries, Correns, Bateson, and Morgan). Biometricians asserted that the really important variation in evolution didn’t follow Mendelian rules. Height, weight, skin color, and similar traits seemed to

Human biochemical genetics

The first of these questions is in the province of sensory physiology, and is the only one for which appreciable understanding has been achieved. This article will be concerned primarily with the second and third questions, which are still subject to a vast amount of speculation, and where the few relevant facts currently supplied by neurophysiology have not yet been integrated into an acceptable theory. With regard to the second question, two alternative positions have been maintained. The first suggests that storage of sensory information is in the form of coded representations or images, with some sort of one-to-one mapping between the sensory stimulus

https://psycnet.apa.org/journals/rev/65/6/386.pdf

The perceptron: a probabilistic model for information storage and organization in the brain.

The perception: a probabilistic model for information storage and organization in the brain

This article describes a scale measuring dispositional optimism, defined in terms of generalized outcome expectancies. Two preliminary studies assessed the scale's psychometric properties and its relationships with several other instruments. The scale was then used in a longitudinal study of symptom reporting among a group of undergraduates. Specifically, respondents were asked to complete three questionnaires 4 weeks before the end of a semester. Included in the questionnaire battery was the measure of optimism, a measure of private self-consciousness, and a 39-item physical symptom checklist. Subjects completed the same set of questionnaires again on the last day of class. Consistent with predictions, subjects who initially reported being highly optimistic were subsequently less likely to report being bothered by symptoms (even after correcting for initial symptom-report levels) than were subjects who initially reported being less optimistic. This effect tended to be stronger among persons high in private self-consciousness than among those lower in private self-consciousness. Discussion centers on other health related applications of the optimism scale, and the relationships between our theoretical orientation and several related theories.

Optimism, coping, and health: Assessment and implications of generalized outcome expectancies.

The cerebellum as a neuronal machine

PART I by Karl R. Popper, Chapter P1: Materialism Transcends Itself, Chapter P2: The Worlds 1, 2 and 3, Chapter P3: Materialism Criticized, Chapter P4: Some Remarks on the Self, Chapter P5: Historical Comments on the Mind-Body Problem, Chapter P6: Summary, Bibliography to Part 1, PART II by John C. Eccles, Chapter E1: The Cerebral Cortex, Chapter E2: Conscious Perception, Chapter E3: Voluntary Movement, Chapter E4: The Language Centres of the Human Brain, Chapter E5: Global Lesions of the Human Cerebrum, Chapter E6: Circumscribed Cerebral Lesions, Chapter E7: The Self-Conscious Mind and the Brain, Chapter E8: Conscious Memory: The Cerebral Processes Concerned in Storage and Retrieval, Bibliography to Part II, PART III Dialogues Between the Two Authors, Bibliography to Part III, Index of Names, Index of Subjects.

/pdf/the-self-and-its-brain-26eid8rt71.pdf

The self and its brain

In the preceding paper (Buller, Eccles & Eccles, 1960) evidence was presented which suggested that the differentiation of slow muscles of the cat hind limb to a large extent failed to occur after certain operative procedures on the spinal cord. This finding indicates that in some way the central nervous system controls muscle differentiation. A more analytic investigation into this postulated influence of nerve on muscle has been accomplished by dividing and cross-uniting nerves to fast and slow muscles, so that motoneurones formerly innervating the fast muscle come to innervate the slow muscle by virtue of the regenerative outgrowth of their fibres, and vice versa for the motoneurones of the slow muscle. The effect of this crossed innervation on the speed of muscle contraction has been tested at varying times after the cross-union. These investigations have also been carried out on animals subjected to the operative procedures on the spinal cord, as previously described (Buller et al. 1960). Cross-union experiments allow in addition an investigation into the possible effects in the reverse direction, i.e. of speed of muscle contraction on the conduction velocity of the axons and the after-hyperpolarization of the motoneurones which innervate it. A preliminary account of part of this investigation has already been published (Bulier, Eccles & Eccles, 1958).

https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/jphysiol.1960.sp006395

Interactions between motoneurones and muscles in respect of the characteristic speeds of their responses.

https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/jphysiol.1957.sp005794

John C. Eccles

Papers

The cerebellum as a neuronal machine

The self and its brain

Interactions between motoneurones and muscles in respect of the characteristic speeds of their responses.

The convergence of monosynaptic excitatory afferents on to many different species of alpha motoneurones

The Self and its Brain.