Development of Receptive Field Properties

Authors: Nigel W Daw

Publish Date: 2014

Volume: , Issue: , Pages: 77-92

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Abstract

Some elements of the organization of the visual system are present at birth There is very substantial development over the first 4 weeks of age in parallel with the large increase in the number of synapses during this period and there is a further refinement of visual properties over the next 3 months or so These ages apply to the cat and are different in the primate but the same general sequence of events occurs in both The elements of a system of orientation columns are there at birth but the selectivity of individual cells within this system of columns develops after birth Some cells are definitely responsive to direction of movement at birth On the other hand the input from the two eyes to the cortex initially overlaps and only segregates into eyespecific columns after birth Sensitivity to disparity develops over the same period as segregation of ocular dominance Acuity improves as the size of the center of the receptive fields of the sustained cells gets smaller and the eyeball gets larger Movement sensitivity improves as the temporal properties of the movement cell system improves The development of physiological properties therefore tallies with the development of psychophysical properties In both cases most properties with the exception of stereopsis exist at birth but substantial refinement and tuning occurs postnatally

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