Fig. 7: Relationship between MT pattern-motion sensitivity and choice-related activity in the plaid segmentation task.
From: A neural correlate of perceptual segmentation in macaque middle temporal cortical area
a Schematic illustration of pattern-component tuning stimuli and hypothetical grating (left) and plaid direction tuning curves (right) (see Materials and Methods). Briefly, if a cell integrates across plaid components to signal pattern motion, then one would expect tuning curves to be identical for single grating and plaid stimuli (last column, solid curve). Conversely, if a cell did not integrate component directions to signal pattern motion, one would expect a bi-lobed tuning curve, with a peak for each direction of plaid motion that translates a single component in the unit’s preferred direction (final column, dashed curve). b (left) Sine grating direction tuning curves for the unit shown in Figs. 3 and 4 (top row – unit from Figs. 3a, b and 4a, b (top); bottom panel – unit from Figs. 3c, d and 4a, b (bottom)). (middle) Pattern and component predictions calculated from the grating tuning profiles. (right) Plaid tuning for these units. The unit in the top (bottom) panel was classified as a pattern (component) cell. Note that there is not a one-to-one correspondence between pattern-component classification and a cell’s coherent/transparent motion preference (cf. textured plaid responses for these units in Fig. 4a). c The z-scored pattern partial correlation coefficient (ordinate) is plotted versus the z-scored component partial correlation coefficient (abscissa) for all cells recorded from monkey N (left) and S (right). Thick lines represent significance criteria used to classify cells. d Grand choice probability (ordinate) is plotted versus pattern index (Zp – Zc) (abscissa). Data in the left (right) panel are from monkey N (S). Black circles highlight data from the example units. In both animals, there was a significant correlation between grand choice probability and pattern index, indicating a greater perceptual correlation for cells that signal pattern direction in stimuli with multiple component directions.
