Moving random lines are better stimuli for far extrastriate brain areas.
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Moving random lines are better stimuli for far extrastriate brain areas.
Neuroscience abstract 2003
Moving random lines are better stimuli for far extrastriate brain
areas.
K. Denys
1
, W. Vanduffel
1,2
, F. Phillips
3
, J.T. Todd
4
and G.A. Orban
1
1
Laboratorium voor Neuro- en Psychofysiologie, K.U.Leuven, Medical School.
2
MGH/MIT/HMS Athinoula A. Martino’s Center for Biomedical Imaging ctr., Boston,
USA.
3
Department of Psychology, Skidmore College, Saratoga Springs, New York
4
Department of Psychology, Ohio State University, Ohio, USA.
The aim of the present fMRI study was to investigate the previous incidental
observations (Sunaert et al., 2000; Vanduffel et al., 2001) suggesting that moving
random lines elicit stronger MR responses than moving random dots in human visual
cortex.
The stimuli consisted of randomly positioned straight lines and randomly positioned
dots, each presented moving and stationary, and each at 2 densities. The number of
pixels for both types of stimuli were matched. We compared the motion effect
(moving minus stationary condition) of the random lines with the motion effect of the
random dots. In a group analysis of 10 human subjects, hMT/V5+, a region in the STS
and regions in the parietal cortex (POIPS, DIPSM, DIPSA) were more sensitive to the
moving line stimuli than to the moving dots. On the other hand, areas V1 and V2
responded more to the moving random dot stimuli than to the moving lines.
To test the hypothesis that the difference between random lines and random dots is
due to a larger amount of structure in the moving random lines, we compared low to
high spatial frequency stimuli and random contour stimuli to their phase scrambled
counterparts. Each stimulus was presented either moving or stationary. Contrasting
the motion effect of these stimuli revealed only early regions and V3A.
The present results indicate that moving random lines are more potent stimuli for
human visual cortex than random dots and that this effect does not reflect low level
structure.
Moving random lines are better stimuli for far extrastriate brain
areas.
K. Denys
1
, W. Vanduffel
1,2
, F. Phillips
3
, J.T. Todd
4
and G.A. Orban
1
1
Laboratorium voor Neuro- en Psychofysiologie, K.U.Leuven, Medical School.
2
MGH/MIT/HMS Athinoula A. Martino’s Center for Biomedical Imaging ctr., Boston,
USA.
3
Department of Psychology, Skidmore College, Saratoga Springs, New York
4
Department of Psychology, Ohio State University, Ohio, USA.
The aim of the present fMRI study was to investigate the previous incidental
observations (Sunaert et al., 2000; Vanduffel et al., 2001) suggesting that moving
random lines elicit stronger MR responses than moving random dots in human visual
cortex.
The stimuli consisted of randomly positioned straight lines and randomly positioned
dots, each presented moving and stationary, and each at 2 densities. The number of
pixels for both types of stimuli were matched. We compared the motion effect
(moving minus stationary condition) of the random lines with the motion effect of the
random dots. In a group analysis of 10 human subjects, hMT/V5+, a region in the STS
and regions in the parietal cortex (POIPS, DIPSM, DIPSA) were more sensitive to the
moving line stimuli than to the moving dots. On the other hand, areas V1 and V2
responded more to the moving random dot stimuli than to the moving lines.
To test the hypothesis that the difference between random lines and random dots is
due to a larger amount of structure in the moving random lines, we compared low to
high spatial frequency stimuli and random contour stimuli to their phase scrambled
counterparts. Each stimulus was presented either moving or stationary. Contrasting
the motion effect of these stimuli revealed only early regions and V3A.
The present results indicate that moving random lines are more potent stimuli for
human visual cortex than random dots and that this effect does not reflect low level
structure.
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