Neural mechanisms underlying the formation of visual saliency in the macaque posteriot parietal cortex

2014 Fiscal Year Final Research Report

• Project/Area Number: 23500391
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Neuroscience in general
• Research Institution: Kyoto University
• Principal Investigator: OGAWA Tadashi 京都大学, 医学(系)研究科(研究院), 准教授 (50311197)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Keywords: 注意 / 眼球運動 / 視覚探索 / サル / サッカード / visual saliency

Outline of Final Research Achievements

The neuronal processes that underlie visual searches can be divided into two stages: target discrimination and saccade preparation/generation. This predicts that the length of time of the pre-discrimination stage varies according to the search difficulty across different stimulus conditions, whereas the length of the latter post-discrimination stage is stimulus-invariant. To address this hypothesis, we recorded single-neuron activity in the lateral intraparietal area (LIP) when monkeys performed a visual search task using different stimulus conditions. The results revealed that post-discrimination intervals varied across stimulus conditions. Further analysis revealed that the post-discrimination interval may vary with stimulus luminance. A computer simulation using an accumulation-to-threshold model suggested that the luminance-related difference in visual response strength at the discrimination time could be the cause of the different post-discrimination intervals.

Free Research Field

神経生理学