Response Modulation of V1 Neurons by Spatiotemporal Sequence of Oriented Stimuli

Spike activity of V1 neurons in response to natural scene (Vinje and Gallant, 2002; Montemurro et al., 2008; Haider et al., 2010) is surprisingly consistent across repeated trials. While it is clear that these responses are not explained by classical receptive field (cRF) properties, it is not known how surround interaction increases the selectivity of V1 response. Put more generally, we do not completely understand the mapping rules between elementary features of visual scene and V1 activity. In the current study we examined the possibility that V1 neurons are selective for spatiotemporal sequence of oriented stimuli. We will describe a novel response property of monkey V1 neurons that visual response was modulated depending on the stimulus onset asynchrony (SOA) in the range of tens of milliseconds between two sequentially presented Gabor stimuli. The preceding stimulus (S1) was presented outside cRF and the following one (S2) inside cRF. S1 alone did not evoke spike response but modulated cell's response to S2. Spike response to S2 was not constant across SOA, and the SOA associated with maximal response modulation varied with the position of S1. These results suggest that V1 neurons are selective for spatiotemporal sequence of oriented stimuli based on surround interaction