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 observers with naturally acquired amblyopia to investigate the neural locus of end-stopped perceptive fields. Results show (1) interocular transfer 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 amblyopic eyes. Together, these results suggest a cortical basis for end-stopped perceptive fields, and that psychophysical end-stopping and flank-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 end-stopped perceptive fields are the psychophysical analogs of cortical end-stopped receptive fields.
Yu
C
C
College of Optometry, University of Houston, TX 77204-6052, USA.
Levi
D M
DM
D000328:Adult; D000550:Amblyopia / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D012684:Sensory Thresholds / Q000502:physiology; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*