The simultaneous coding of orientation and contrast in the responses of V1 complex cells.
The responses of 30 V1 complex cells were recorded using a complete set of transiently presented, oriented stimuli of different contrasts. A back-propagation neural network was used to predict the multivariate visual stimuli from the neuronal responses on a trial-by-trial basis. For single neurons, the strength of the response was much better at predicting the orientation of a visual stimulus than its contrast. Using the temporal modulation of the response improved the ability to predict the contrast of a stimulus without affecting the ability to predict the orientation. Removing stimulus latency from the responses, by time-shifting the individual responses an amount equal to the average latency, significantly reduced the ability to predict stimulus contrast, demonstrating that the response latency is reliable enough, even for a single neuron and a single trial, for it to be used to help determine stimulus contrast. Pooling the responses from a group of 11 neurons demonstrated that small groups of neurons can accurately represent multivariate stimuli in a single trial.
Gawne
T J
TJ
Department of Physiological Optics, University of Alabama at Birmingham, 35294, USA. Tgawne@icare.opt.uab.edu
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D015350:Contrast Sensitivity / Q000502:physiology*; D008253:Macaca mulatta; D009474:Neurons / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*