neurophysiology: an integration 



1945 



experience and exercise. Indeed, even so slight and 

 transient an experience as the perceptual distortions 

 produced by saturation in figural afterimages of 

 vision, touch and proprioception (160) can last for 

 months after a single experience (292). 



The world image. The raw experience of the infant 

 is progressively categorized and differentiated to the 

 highly discriminative perceptions and conceptions of 

 the adult by successive steps of patterning in the 

 nervous system. The larger categories are established 

 early, the lesser ones fall within the limits set by these, 

 finer and still finer ones forming in turn, each smaller 

 discrimination coming later and being less fixed than 

 the larger category. So leaf petioles and twigs and 

 branches and boughs develop from the initial stem; 

 so a geometrical doodler forms a large triangle and 

 then divides this into smaller ones, and these into 

 smaller ones, down to the limits set by pencil lines. 

 Constant or regularly repeated constellations ol 

 sensory inputs generate the entities of our universe 

 of experience, initially the material objects. This 

 experience is not at first referred to the outside; to the 

 infant all is "I.' Later a 'not I' or 'thou' is separated 

 and only still later is the personified 'thou' further 

 divided to discriminate the impersonal 'it.' Then 

 come the major categories of materia] entities, then 

 the functional ones, and so on. 



At each stage greater abstraction, as well .is 

 particularization, is att. lined. This corresponds to the 

 inevitable filtering and loss of incoming information, 

 but the category, like a coding rule, allows more lo be 

 retained and used. The wav in which a terrain 1- 

 conceptually mapped in three dimensions l>\ primitive 

 mountain people under the guidance of sophisticated 

 Europeans, and the comparable way in which a child 

 grasps spatial and logical relationships has been 

 beautifully described by Bronowski (•.];])■ Schilder 

 (261) and Piaget (231) present like material. Only 

 after extensive overlearning of a finger manipulation 

 does a subject develop a visual image of what has 

 been learned through touch and proprioception 

 (190; see also 35). Similarly, the well-experienced 

 pilot, handling his controls in an emergency, often 

 'sees' the entire plane, as if watching it in free space, 

 respond with appropriate maneuvers. 



Learning, on perceptual, motor and ideational 

 sides alike, probably invokes the formation of pattern 

 elements in the brain, partial assemblies or the like 

 [cf. Milner (212)], which can then be combined into 

 larger and still larger functional wholes. The teleg- 

 rapher, learning to receive Morse code, improves to 

 plateaus of letter recognition, word recognition and, 



finally, phrase recognition; new gestalts are formed 

 or, in modern terms, bits of information are grouped 

 into chunks (208). Motor skills are similarly built of 

 established acts, each usable in many complete 

 repertoires (Paillard) — as in mastering different 

 piano pieces. And, of course, the new arises in imagi- 

 nation by a similar recombination (94, 112). 



When elements used in some performance have 

 been learned and previously used in like relations, 

 they fit easily and are compatible (73). Performance 

 on a problem is then faster and more correct than 

 when incompatible sensory and motor components 

 must be brought together. When new combinations 

 are required, conversely, learning is far easier because 

 of the pre-established elements than if the brain had 

 10 start at scratch witness the inverted manipula- 

 tions under a microscope or the use ol esophageal 

 speech after loss of the larynx (Zangwill). In the 

 reverse direction, with loss of functional capacity, 

 as in aging, integrated behavior fragments back to its 

 components. Even lack of practice causes such for- 

 getting regression, and this might be related to the 

 phenomena of sensor) deprivation. At least, visual 

 rhythms are abolished after hours of darkness (60 . 

 just .1- the) .iic broken bv patterned light. 



Timing is obviously critical in such combinative 

 processes. This may account for the disruption of 

 thought and speech by delayed auditory feedback. 

 The presence of properly timed potentials, appearing 

 in both specific and nonspecific systems, onl) when 

 the correct behavior follows ,1 visual flicker stimulus, 

 is a case in point ( [52; see also Galambos is: Morgan). 

 The marked differences in perceived patterns when a 

 Stroboscopic field is displayed to one or to both eyes 

 (_>(>(>, j(>7> is a related spatial phenomenon. Similarly, 

 in normal development, when strabismus gives double 

 images, impulses from one eve become suppressed and, 

 on the motor side, one hemisphere comes to dominate 

 the other — there is no language defect in children 

 following damage 10 die speech area of either cortex 

 (Zangwill J. 



The traces left by experience are real and specific 

 patterns in the nervous system, with morphological 

 locus and physiological properties. True, at first there 

 is widespread participation of brain neurons (Living- 

 ston; 21, 147, 183), especially with meaningful 

 stimuli (77), and much freedom as to which groups 

 finallv become "channelized" for particular functions; 

 nevertheless experimentation, such as the evocation of 

 specific memories I ,y punctate stimulation of the 

 temporal lobe (Penfield), is rapidly bringing these 

 traces from the realm of postulated constructs to that 



