Spatial frequency and visual persistence: cortical reset.
Psychophysical studies show that the duration of visual persistence increases with spatial frequency of gratings. Previous theories ascribe this finding to differences between the spatial and temporal properties of sustained and transient pathways. This paper proposes an alternative account that explains persistence as a side-effect of excitatory feedback in neural circuits for contour extraction. Mechanisms to break excitatory feedback include inhibitory reset signals at stimulus offset. Simulations demonstrate how gratings with lower spatial frequency generate stronger inhibitory reset signals, thereby resulting in shorter persistence for lower spatial frequencies. Additional simulations account for interactions of spatial frequency with stimulus duration, effects of adaptation, and properties of residual traces, as opposed to visual persistence.
Francis
G
G
Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907-1364, USA. gfrancis@psych.purdue.edu
D000221:Adaptation, Ocular / Q000502:physiology; D003198:Computer Simulation; D005246:Feedback; D006801:Humans; D010775:Photic Stimulation; D011601:Psychophysics / Q000379:methods; D013028:Space Perception / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*