Energy and phase orientation mechanisms: a computational model.

Publisher: VSP Country of Publication: Netherlands NLM ID: 8602662 Publication Model: Print Cited Medium: Print ISSN: 0169-1015 (Print) Linking ISSN: 01691015 NLM ISO Abbreviation: Spat Vis Subsets: MEDLINE

Publication: Utrecht : VSP
Original Publication: Utrecht, The Netherlands : VNU Science Press, c1985-2009.

Computer Simulation* ; Models, Neurological*; Orientation/*physiology ; Space Perception/*physiology; Humans ; Visual Cortex/physiology

A computational model is proposed for spatial orientation processing beyond the initial stage of linear filtering in visual cortex. The model accounts for orientation pop-out, edge location and orientation, and bar location and orientation. It naturally extends to higher order orientation symmetries. The model is consistent with much of the current understanding of early processing in mammalian visual cortex. It builds on the notions of orientation and spatial frequency specific simple cells, any subsequent non-linearity, and orientation 'pooling'. The processing treats simple cell energy, real, and imaginary responses in a unified way to generate 'feature maps'. The 'pooling' operation in each case is a discrete Fourier transform of the simple cell responses over orientation. The suggested processing has implications for psychophysics (e.g. providing an explanation of why orientation discrimination thresholds are more than an order of magnitude less than simple cell orientation bandwidths), provides some understanding of the variety of 'complex-cell' properties found in visual cortex, and provides a plausible starting point for subsequent processing.

Date Created: 20021119 Date Completed: 20030106 Latest Revision: 20191106

20240627

10.1163/156856802320401892

12434822