Spiral motion selective neurons in area MSTd contribute to judgments of heading.

Self-motion generates patterns of optic flow on the retina. Neurons in the dorsal part of the medial superior temporal area (MSTd) are selective for these optic flow patterns. It has been shown that neurons in this area that are selective for expanding optic flow fields are involved in heading judgments. We wondered how subpopulations of MSTd neurons, those tuned for expansion, rotation or spiral motion, contribute to heading perception. To investigate this question, we recorded from neurons in area MSTd with diverse tuning properties, while the animals performed a heading-discrimination task. We found a significant trial-to-trial correlation (choice probability) between the MSTd neurons and the animals' decision. Neurons in different subpopulations did not differ significantly in terms of their choice probability. Instead, choice probability was strongly related to the sensitivity of the neuron in our sample, regardless of tuning preference. We conclude that a variety of subpopulations of MSTd neurons with different tuning properties contribute to heading judgments.