| | |
Summary: Segmentation by Color Influences Responses of Motion-Sensitive
Neurons in the Cortical Middle Temporal Visual Area
Lisa J. Croner1 and Thomas D. Albright1,2
1Vision Center Laboratory, and 2Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla,
California 92037
We previously showed that human subjects are better able to
discriminate the direction of a motion signal in dynamic noise
when the signal is distinguished (segmented) from the noise by
color. This finding suggested a hitherto unexplored avenue of
interaction between motion and color pathways in the primate
visual system. To examine whether chromatic segmentation
exerts a similar influence on cortical neurons that contribute to
motion direction discrimination, we have now compared the
discriminative capacity of single MT neurons and psychophys-
ical observers viewing motion signals with and without chro-
matic segmentation. All data were obtained from rhesus mon-
keys trained to discriminate motion direction in dynamic stimuli
containing varying proportions of coherently moving (signal)
and randomly moving (noise) dots. We obtained psychophysi-
cal and neurophysiological data in the same animals, on the
|
