Figure 9. Emergent Visual Stimulus Selectivity in Cortical Visual Area mt following Paired Association Learning.

Subjects learned to associate up and down motions with up and down arrows. (A) Neurophysiological data are shown from a representative mt neuron. The top row illustrates responses to four motion directions. Each of the four plots in this row contains a spike raster display (in which each tic mark indicates the occurrence of an action potential) of the neuronal response obtained for each presentation of the stimulus. Each plot also contains a function that represents the average neuronal response rate as a function of time relative to stimulus onset (time = 0). For each plot, the vertical dashed lines correspond from left to right to stimulus onset, motion onset, and stimulus offset. The gray rectangle indicates the analysis window. The cell was highly directionally selective. The responses to downward and leftward motion were far greater than the responses to upward and rightward motion. The bottom row of plots illustrates responses to four static arrows. Plotting conventions are the same as in the upper row. As a consequence of learning, the cell became highly selective for arrow direction. Responses to the downward and leftward arrows are greatest.

(B) Mean responses of the neuron shown in panel A to motion directions (dashed curve) and corresponding static arrow directions (solid curve), indicated in polar format (polar angle corresponds to stimulus direction and radius corresponds to neuronal response rate). Preferred directions for the two stimulus types (dashed and solid vectors) are nearly identical.

Source: Anja Schlack and Thomas D. Albright, “Remembering Visual Motion: Neural Correlates of Associative Plasticity and Motion Recall in Cortical Area mt,” Neuron 53 (2007): 881–890.