QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, October 21, 2009, 29(42):13210-13221; doi:10.1523/JNEUROSCI.1995-09.2009

This Article Full Text Full Text (PDF) Supplemental Material Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Yokoi, I. Articles by Komatsu, H. PubMed PubMed Citation Articles by Yokoi, I. Articles by Komatsu, H.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Relationship between Neural Responses and Visual Grouping in the Monkey Parietal Cortex

Isao Yokoi^1,2 and Hidehiko Komatsu^1,2

¹Division of Sensory and Cognitive Information, National Institute for Physiological Sciences, Okazaki 444-8585, Aichi, Japan, and ²Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan

Correspondence should be addressed to Dr. Hidehiko Komatsu, Division of Sensory and Cognitive Information, National Institute for Physiological Sciences, Myoudaiji, Okazaki, 444-8585, Aichi, Japan. E-mail: Email: komatsu{at}nips.ac.jp

Visual grouping through the binding of multiple discrete elements is an important component of object perception, and neurological studies have shown that the posterior parietal cortex plays a vital role in that process. To study the neural mechanisms underlying visual grouping, we recorded neuronal activity from the lateral bank of the intraparietal sulcus (L-IPS) of monkeys while they performed a task that required them to discriminate among rapidly presented visual patterns composed of five black or white dots arranged in a cross. The monkeys had to detect the patterns in which dots with the same contrast were arranged either horizontally or vertically (target). Visual grouping was necessary for detection of the target, and we surmised that if L-IPS neurons are involved in visual grouping, they may selectively respond to the grouped objects. In addition, we manipulated the monkeys' attention to the grouping of the elements. We found that many L-IPS neurons showed selectivity for the orientation of the target stimuli, and that selectivity was enhanced by the top-down attention. Moreover, the selectivity correlated with behavioral performance. These results provide the first physiological evidence that L-IPS neurons make a crucial contribution to visual grouping by combining visual and attentional signals so as to bind discrete visual elements together.

---

Received April 27, 2009; revised Aug. 18, 2009; accepted Sept. 11, 2009.

Correspondence should be addressed to Dr. Hidehiko Komatsu, Division of Sensory and Cognitive Information, National Institute for Physiological Sciences, Myoudaiji, Okazaki, 444-8585, Aichi, Japan. E-mail: Email: komatsu{at}nips.ac.jp

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help