Top-Down Inputs Enhance Orientation Selectivity in Neurons of the Primary Visual Cortex during Perceptual Learning
Figure 5
Stimulus specificity of tuning curve changes.
A. Training the model with stimulus A strengthened the feedforward and feedback connections between stimulus-specific populations of V1 and V2 neurons. B. A test stimulus B (green) activated population of neurons in V1 and V2 that included some neurons with the modified synapses. The red circle shows where the trained stimulus A was presented to the model. C. Another test stimulus C (purple) activated populations of V1 and V2 neurons that did not include neurons with modified synapses. D. Before training, the strength of the feedback inputs was equal for any applied stimulus (grey dashed line). After training, the strength of feedback inputs depended on the applied stimulus (black solid line). E. Stimulus specificity of changes to tuning curves. Peaks of tuning curves did not change, but amplitudes and widths of the tuning curves changed depending on the distance from the trained orientation.