The effect of disrupting the human magnocellular pathway on global motion perception.
The purpose of this study was to demonstrate the effect of human magnocellular (M)-pathway disruption on global motion perception. Coherence thresholds for global motion direction discrimination in random dot patterns were determined at slow and moderate dot speeds: (1) after adaptation to full-field sinusoidal flicker or a steady gray field, and (2) on a red or a gray background. Adaptation to flicker and a red background increased motion coherence thresholds relative to the gray baseline conditions at both dot speeds. Physiological studies have shown that M cells in the retina and LGN are inhibited by red light and are a main contributor to flicker perception in monkeys. Therefore, our results suggest that interference with processing in the subcortical M pathway disrupts higher-level motion integration.
Chapman
Craig
C
Department of Ophthalmology and Visual Sciences, University of British Columbia, 4480 Oak Street, Room A146, Vancouver, BC, Canada V6H 3V4.
Hoag
Ryan
R
Giaschi
Deborah
D
D000293:Adolescent; D000328:Adult; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D012684:Sensory Thresholds; D014795:Visual Pathways / Q000502:physiology*