CORTICAL END-STOPPED PERCEPTIVE FIELDS - EVIDENCE FROM DICHOPTIC AND AMBLYOPIC STUDIES

Psychophysical length and width spatial interactions associated with a line target were measured in normal observers dichoptically and in ob servers with naturally acquired amblyopia to investigate the neural lo cus of end-stopped perceptive fields, Results show (1) interocular tra nsfer of psychophysical end-stopping, flank-inhibition, and length and width summation; and (2) severe, but significantly different, loss of end-stopping and flank-inhibition in the central visual fields of amb lyopic eyes. Together, these results suggest a cortical basis for end- stopped perceptive fields, and that psychophysical end-stopping and fl ank-inhibition are a consequence of distinct cortical inhibition, The damaging effects of amblyopia on end-stopping and flank-inhibition are weaker and less different from each other under transient conditions, Our results provide further evidence supporting the suggestion that e nd-stopped perceptive fields are the psychophysical analogs of cortica l end-stopped receptive fields. (C) 1997 Published by Elsevier Science Ltd.