HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 90/6/3912    most recent 00219.2003v1 Alert me when this article is cited 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 Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Wang, G. Articles by Yunokuchi, K. Search for Related Content PubMed PubMed Citation Articles by Wang, G. Articles by Yunokuchi, K.

Representation of Cardinal Contour Overlaps Less With Representation of Nearby Angles in Cat Visual Cortex

¹ Department of Bioengineering, Faculty of Engineering, Kagoshima University, Kagoshima 890-0065 ² Department of Public Health, Faculty of Medicine, Kagoshima University, Kagoshima 890-8250, Japan

Submitted 6 March 2003; accepted in final form 13 August 2003

Extensive attempts have been made to explain the neurobiological basis of the greater sensitivity of the visual system to vertically or horizontally oriented information than to information presented at oblique angles. However, investigators have largely ignored the overlap of the representation of a given angle with the representation of nearby angles. Recordings based on intrinsic optical signals were obtained in area 17 from 12 adult cats during the presentation of contours in various orientations. A method investigating both amplitude and statistical significance of changes was proposed to evaluate the orientation tuning properties for cell populations in the central area retinotopically corresponding to 0–15° of visual field. Cardinal orientations were found to activate significantly greater areas in the exposed cortical area than the areas activated by oblique orientations. Areas activated by cardinal or oblique contours and those separated from them by 10° were compared. A significantly lower degree of overlap was seen between areas activated by presentation of cardinal contours and areas activated by neighboring orientations compared with those for oblique orientations which overlapped more extensively with neighboring orientations. In addition, areas activated only by cardinal contours were significantly larger than areas activated only by oblique contours. These results demonstrated in cell population level that more cells prefer horizontal or vertical orientations, and these cells are tuned more sharply than oblique selective cells.

This article has been cited by other articles:

				X. Xu, C. E. Collins, I. Khaytin, J. H. Kaas, and V. A. Casagrande Unequal representation of cardinal vs. oblique orientations in the middle temporal visual area PNAS, November 14, 2006; 103(46): 17490 - 17495. [Abstract] [Full Text] [PDF]