Neurophysiological evaluation of the differential response model for orientation and spatial-frequency discrimination.
Recent models have attempted to reconcile low psychophysical orientation and spatial-frequency discrimination thresholds with relatively broad orientation and spatial-frequency tuning of cortical neurons. These models have relied on the ability of the neurons to convert small stimulus changes into reliable response changes. We have examined this ability in a sample of neurons from the cat's striate cortex. We present here data from two cells that reliably signaled the smallest orientation and spatial-frequency differences. Using receiver operating characteristic analysis, we find that these cells could reliably signal orientation differences of 1.84 deg and spatial-frequency differences of 0.073 octave. We compare these single-cell results to cat and human behavioral discrimination thresholds.
D000818:Animals; D002415:Cats; D004193:Discrimination Learning / Q000502:physiology*; D005074:Evoked Potentials, Visual; D009039:Motion Perception / Q000502:physiology; D009474:Neurons / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D011601:Psychophysics; D012684:Sensory Thresholds; D013028:Space Perception / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*