Modulation of V1 spike response by temporal interval of spatiotemporal stimulus sequence

PLoS One. 2012;7(10):e47543. doi: 10.1371/journal.pone.0047543. Epub 2012 Oct 16.

Abstract

The spike activity of single neurons of the primary visual cortex (V1) becomes more selective and reliable in response to wide-field natural scenes compared to smaller stimuli confined to the classical receptive field (RF). However, it is largely unknown what aspects of natural scenes increase the selectivity of V1 neurons. One hypothesis is that modulation by surround interaction is highly sensitive to small changes in spatiotemporal aspects of RF surround. Such a fine-tuned modulation would enable single neurons to hold information about spatiotemporal sequences of oriented stimuli, which extends the role of V1 neurons as a simple spatiotemporal filter confined to the RF. In the current study, we examined the hypothesis in the V1 of awake behaving monkeys, by testing whether the spike response of single V1 neurons is modulated by temporal interval of spatiotemporal stimulus sequence encompassing inside and outside the RF. We used two identical Gabor stimuli that were sequentially presented with a variable stimulus onset asynchrony (SOA): the preceding one (S1) outside the RF and the following one (S2) in the RF. This stimulus configuration enabled us to examine the spatiotemporal selectivity of response modulation from a focal surround region. Although S1 alone did not evoke spike responses, visual response to S2 was modulated for SOA in the range of tens of milliseconds. These results suggest that V1 neurons participate in processing spatiotemporal sequences of oriented stimuli extending outside the RF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Macaca mulatta
  • Male
  • Neurons / physiology*
  • Physical Stimulation
  • Visual Cortex / physiology*
  • Visual Perception / physiology*

Grants and funding

This research was supported by the Cognitive Neuroscience Research Program of the Korean Ministry of Education, Science and Technology, and the Brain Fusion Program of the Seoul National University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.