The Journal of Neuroscience, November 2, 2005, 25(44):10299-10307; doi:10.1523/JNEUROSCI.3036-05.2005
Previous Article | Next Article 
Behavioral/Systems/Cognitive
Dynamically Modulated Spike Correlation in Monkey Inferior Temporal Cortex Depending on the Feature Configuration within a Whole Object
Toshiyuki Hirabayashi and
Yasushi Miyashita
Department of Physiology, The University of Tokyo School of Medicine, Bunkyo-ku, Tokyo 113-0033, Japan
The mechanism underlying the processing of spatially separated multiple local features to form a unique whole object is an important issue in visual object recognition. We tested whether, in behaving monkeys, the spike correlation between pairs of inferior temporal (IT) neurons dynamically changes depending on the spatial configuration of the local features within a whole object. We prepared more than 60,000 face-like objects (FOs) and their corresponding non-face-like objects (NFOs) that consisted of random arrangements of the same set of local features as those in FOs. The spike correlation between a pair of neurons was quantified by the peak height of the shift predictor-subtracted cross-correlogram. For both neurons of the pair, the local features in a whole object were determined so that they elicited as high a response as possible to enable a reliable cross-correlation analysis. We found that the FOs thus constructed elicited neuronal activities that were more strongly correlated than the corresponding NFOs. Firing rates of the same neurons did not show such a consistent bias depending on the feature configuration. Furthermore, receiver operating characteristic analysis revealed that this FO dominance of spike correlation was robust enough to discriminate between different feature configurations at the population level. Spike correlation of the cell pairs exhibited significant FO dominance within 300 ms after stimulus onset. The present results suggest that feature configuration within a unique whole object can be reflected in the rapid modulation of spike correlation among a population of neurons in the IT cortex.
Key words: cross-correlation analysis; cell assembly; visual object recognition; inferior temporal cortex; macaque monkey; neurophysiology
Received July 22, 2005;
revised September 28, 2005;
accepted September 28, 2005.
This article has been cited by other articles:

|
 |

|
 |
 
J. M. Samonds
Feature Configuration Modulates Effective Connectivity
J. Neurosci.,
April 5, 2006;
26(14):
3621 - 3623.
[Full Text]
[PDF]
|
 |
|