Ml-1 



II VNDBOOK OF I'HYSlcil ( i(, Y 



NKt'ROl'HYSlOl.OOY III 



maturing institution depend on an epigenetic 

 rather than a preformed mechanism fur growth and 

 elaboration. The particular machinery of polv nucleo- 

 tide or protein synthesis has no surface relation to 

 that for building new neuron connections or to that 

 for setting new sonograms in a business firm. Yet in 

 all cases there exist: first, some initial organization, a 

 template of sorts which guides the pattern of the 

 new formation; and second, some operational rules 

 that lead to kinds of outcomes, with the particulars 

 left to the detailed conditions of environment-system 

 interaction. This is the great invention underlying all 

 progressive change in living systems, the epigenetic 

 mode. Only in a primitive way do present artifacts 

 learn (12, 1 ■>,, 290); but, as noted, they have begun 

 to learn to learn. 



INFORMATION. Given a material system, with its 

 supra- and subsystems and with its material and 

 functional units, there arise the questions, first, of the 

 influences that operate between units, involving the 

 kind and structure of the connections between them, 

 and second, of the mechanisms by which changes are 

 induced. Across the boundary of a system or a unit 

 may How material, energy, and information the 

 long-recognized biological factors of transportation, 

 mechanical influence and transmission. The nervous 

 s\ stem is overwhelmingly concerned with information; 

 hut the flow of substance and energy is involved in 

 its maintenance and responses, and transducers are 

 operating throughout the central system and its 

 receptor and effector attachments to effect transforma- 

 tions between mechanical, electrical, chemical and 

 other changes, and the nerve messages that initiate or 

 result from these. 



11m transform functions relating input to internal 

 change to output are being intensively examined for 

 all suns cil flows through all sorts of systems. The 

 action spectrum of chlorophyll, die frequency response 

 curve cii nerve, the conditioning patterns of rats, and 

 die performance ol a submarine and iis crew under 

 depth bomb attack each involves the appropriate 

 transform Functions; hut the formal problem is alike 



in .ill, and some common model formulations and 



analytic procedures an- proving widely useful. The 

 fixing oi experience in genes and proteins, in cellular 



immune reactions, in neural engrams and individual 

 memories, in group customs and libraries is also 

 formally -111111.11 (104, 1 1 v- Bui the exploration of 

 inization, long restricted 10 structure, is now 

 bursting into die area ol action; patterns in time and 

 space, and their interactions, involved in handling 

 iuli 11 mat ion, ai e now .1 focus of research. 



HOMEOSTASIS. All dynamic sWeius that endure have 

 homeostatic mechanisms through which they are 

 able to marshall their resources in counteracting 

 disturbances and re-establishing, or moving towards, 

 the initial equilibrium. The\ also have mechanisms 

 lor altering with experience and shifting their slate 

 (including probability expectations! as a result of it, 

 some sort of learning and remembering. Negative 

 feedback is an outstanding homeostatic device of the 

 nervous system; accommodation, adaptation and 

 modification arc ways of adjusting to environmental 

 change. 



Finally, every svstem of interest here has a range 

 of behavioral possibilities th.it, however fully deter- 

 mined, appear as choices or decisions. There is 'goal- 

 directed' behavior at the cellular level in morpho- 

 genesis including the 'seeking' of the tit-Id of innerva- 

 tion by growing nerve fibers (j(|i 1, at the organ level 

 in development, seen elegantlv in the series ol activa- 

 tions of neural hormones in insect metamorphosis 

 (294); at all levels, from molecule to species, as a 

 form of learning or microevolution (1041 Molecules 

 may polymerize in one or another pattern, neurons 

 may fire or not; locomotion may begin with the 

 right or left leg, and it may be directed to objective 

 A or B; species may solve an environmental problem 

 by a variety of adaptive answers. In the nervous 

 svstem, the synapses arc the 'points of decision' and 

 their 'table of organization 1 is of major importance. 

 Through this organization information Hows in and 

 instructions flow out, and end patterns of consciousness 

 and behavior result. An army or a computer functions 

 in a comparable manner. 



SETTING OF THE NERVOUS SYS 1 1 VI 



Psychology and Physiology; the Black Box 



ll is an important decision in research Strategy to 

 decide, in attacking anv '_;iven problem, at which 

 level and to what type of unit within it attention will 

 be directed. The bitter arguments between holisl and 

 reductionist approaches are largelv due to a failure 



to recognize these possible choices. The psychologist, 

 establishing stimulus-response relations lor a rat or a 

 man, is proceeding as did the physicist in relating 

 electric currents to magnetic fields, or die neuro- 

 physiologist in relating the discharges of a neuron to 

 die presynaptic barrage. Analysis of mechanisms 

 .ilwavs leads die querj to a lower level organism 

 behavior to neurons, neuron behavior 10 molecules 



m<\ ions bin wolk is sound and neccss.irv within as 

 well as across levels. 



