Neuronal activity in MST and STPp, but not MT changes systematically with stimulus-independent decisions
A. Thiele & K.-P. Hoffmann
Neuroreport, 7:971-976, 1996
- Single units in the middle temporal area (MT), the middle superior temporal area (MST) and the upper part of
the superior temporal polysensory area (STPp) of the monkey's brain were recorded during the discrimination of
direction of visual motion near contrast threshold. In addition to stimulus-related decisions the monkeys often
made stimulus-independent decisions while stimuli were well below detection threshold (contrast < 0.01%), or
totally absent. During this condition MT neurones showed no systematic changes in their ongoing activity while
in the MST and STPp stimulus-independent decisions in the preferred direction of a given neurone were accompanied
by the highest ongoing activity. We take this as evidence for internally generated representations of direction
of motion in higher visual areas of the superior temporal sulcus. Neurones involved in the initiation of a decision
or action are described for the first time in area STPp.
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