RT Journal Article
SR Electronic
T1 Middle Temporal Visual Area Microstimulation Influences Veridical Judgments of Motion Direction
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 9530
OP 9540
DO 10.1523/JNEUROSCI.22-21-09530.2002
VO 22
IS 21
A1 Nichols, M. James
A1 Newsome, William T.
YR 2002
UL http://www.jneurosci.org/content/22/21/9530.abstract
AB Microstimulation of direction columns in the middle temporal visual area (MT, or V5) provides a powerful tool for probing the relationship between cortical physiology and visual motion perception. In the current study we obtained “veridical” reports of perceived motion from rhesus monkeys by permitting a continuous range of possible responses that mapped isomorphically onto a continuous range of possible motion directions. In contrast to previous studies, therefore, the animals were freed from experimenter-imposed “categories” that typify forced choice tasks. We report three new findings: (1) MT neurons with widely disparate preferred directions can cooperate to shape direction estimates, inconsistent with a pure “winner-take-all” read-out algorithm and consistent with a distributed coding scheme like vector averaging, whereas neurons with nearly opposite preferred directions seem to compete in a manner consistent with the winner-take-all hypothesis, (2) microstimulation can influence direction estimates even when paired with the most powerful motion stimuli available, and (3) microstimulation effects can be elicited when a manual response (instead of our standard oculomotor response) is used to communicate the perceptual report.