RT Journal Article
SR Electronic
T1 Does primate motion perception depend on the magnocellular pathway?
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 3422
OP 3429
DO 10.1523/JNEUROSCI.11-11-03422.1991
VO 11
IS 11
A1 WH Merigan
A1 CE Byrne
A1 JH Maunsell
YR 1991
UL http://www.jneurosci.org/content/11/11/3422.abstract
AB This study examined the importance of the primate magnocellular retinocortical pathway in the perception of moving stimuli. A portion of the magnocellular pathway was permanently and selectively interrupted by ibotenic acid injections in the LGN of macaque monkeys. We then tested contrast sensitivity for detecting moving stimuli, as well as two indices of motion perception, contrast sensitivity for opposite direction discrimination and speed difference thresholds, in the affected portion of the visual field. Magnocellular lesions greatly reduced detection contrast sensitivity at high temporal and low spatial frequencies and had a similar effect on contrast sensitivity for opposite direction discrimination under these same stimulus conditions. Consequently, opposite direction discriminations could be made at contrast threshold, suggesting that magnocellular lesions reduced the visibility of stimuli used to test direction perception, but did not act directly on direction perception. Magnocellular lesions also elevated speed difference thresholds under some stimulus conditions. However, this deficit was reduced or eliminated by raising the contrast of the test stimulus. Together, these findings suggest that magnocellular lesions reduce the visibility of stimuli used to test motion perception but that they do not appear to alter motion perception otherwise.