Spatial computation performed by simple and complex cells in the visual cortex of the cat.
Simple and complex cells have been tested with drifting sine-wave and square-wave gratings. Despite the known differences in the response pattern of each cell type to drifting sine-wave gratings, the tuning curves for square-wave gratings for both cell types show a similar secondary response band peaking at one-third the preferred spatial frequency as determined from sine-wave studies. These results establish that both cell types respond predominantly to the third harmonic of square-wave gratings in this frequency range. At the simple cell stage, all the information required to specify the amplitude and phase for channel at a given orientation, direction and spatial frequency can be conveyed by four cells for a given subsection of visual space. At the complex cell stage, the cell's mean firing rate appears to represent the amplitude of a local Fourier coefficient, but phase information is not conveyed in the action potential code.
D000818:Animals; D002415:Cats; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation / Q000295:instrumentation / Q000379:methods; D013028:Space Perception / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*