第29回日本神経科学大会(京都)
平成18年7月19日〜21日
Program Number: PS3A-G107 Presentation Time: Friday, July. 21, 11:00 - 12:00

Neural correlates of stimulus shape detection in monkey inferior temporal cortex

Taijiro Doi1

1Lab. Cogn., Neurosci., Osaka Univ., Japan, 2Lab. Cogn. Neurosci., Osaka Univ., Japan

We searched for a neural "correlate" of conscious perception of shape by recording neuronal activities from inferior temporal (IT) cortex while a monkey performed a 3-choice shape detection task. The monkey was required to judge whether or not a sample stimulus was presented immediately after a forward masking stimulus. When there was, the monkey was required to select the stimulus identical to the sample from three targets, two shapes and one small dot. Trial-to-trial variation of firing rates of many IT neurons correlated with the monkey's seen vs. not-seen choices. The mean choice probability (CP) of IT neurons was 0.58, a value significantly larger than the chance level. Neurons with stronger visual responses exhibited larger CPs. We also searched for temporal firing patterns within the spike train from a single neuron or across 2-3 simultaneously recorded neurons, but failed to find any temporal structure related to the monkey's behavioral choice. The results indicate a link between the firing rates of IT neurons with conscious perception of stimulus shape.

Keywords: PERCEPTION, INFERIOR TEMPORAL CORTEX

Reserch Funds: Supported by MEXT grant (17022025).