|
|
||||||||
1NTT Communication Science Laboratories, Nippon Telegraph and Telephone Corporation, Atsugi, Kanagawa 243-0198, Japan; 2Massachusetts General Hospital, Nuclear Magnetic Resonance Center, Charlestown, Massachusetts 02129; 3Department of Radiology, Harvard Medical School, Boston, 02115; and 4Department of Psychology, Boston University, Boston, Massachusetts 02215
Submitted 18 July 2003; accepted in final form 7 August 2003
Psychophysical findings have revealed a functional segregation of processing for 1st-order motion (movement of luminance modulation) and 2nd-order motion (e.g., movement of contrast modulation). However neural correlates of this psychophysical distinction remain controversial. To test for a corresponding anatomical segregation, we conducted a new functional magnetic resonance imaging (fMRI) study to localize direction-selective cortical mechanisms for 1st- and 2nd-order motion stimuli, by measuring direction-contingent response changes induced by motion adaptation, with deliberate control of attention. The 2nd-order motion stimulus generated direction-selective adaptation in a wide range of visual cortical areas, including areas V1, V2, V3, VP, V3A, V4v, and MT+. Moreover, the pattern of activity was similar to that obtained with 1st-order motion stimuli. Contrary to expectations from psychophysics, these results suggest that in the human visual cortex, the direction of 2nd-order motion is represented as early as V1. In addition, we found no obvious anatomical segregation in the neural substrates for 1st- and 2nd-order motion processing that can be resolved using standard fMRI.
This article has been cited by other articles:
![]() |
K. Amano, T. Kimura, S. Nishida, T. Takeda, and H. Gomi Close Similarity Between Spatiotemporal Frequency Tunings of Human Cortical Responses and Involuntary Manual Following Responses to Visual Motion J Neurophysiol, February 1, 2009; 101(2): 888 - 897. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Ashida, A. Lingnau, M. B. Wall, and A. T. Smith fMRI Adaptation Reveals Separate Mechanisms for First-Order and Second-Order Motion J Neurophysiol, February 1, 2007; 97(2): 1319 - 1325. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Larsson, M. S. Landy, and D. J. Heeger Orientation-Selective Adaptation to First- and Second-Order Patterns in Human Visual Cortex J Neurophysiol, February 1, 2006; 95(2): 862 - 881. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Noguchi, Y. Kaneoke, R. Kakigi, H. C. Tanabe, and N. Sadato Role of the Superior Temporal Region in Human Visual Motion Perception Cereb Cortex, October 1, 2005; 15(10): 1592 - 1601. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |