NpgRJ_Nn_1991 1608..1614

In perceptual tasks, subjects attempt to rely on their most informative cues. Such strategic choices should be reflected in the types of sensory neurons that are used. We investigated this in a binocular-disparity discrimination task. Using psychophysical reverse-correlation, also known as image classification, we identified the perceptual strategies of two macaques (Macaca mulatta). Correlations between reported disparity signs and disparity noise samples for each trial yielded detection ‘filters’. Filter amplitude was greater at near disparities than at far disparities, indicating that the subjects relied more on near disparities. Recordings from both macaques’ disparity-selective V2 neurons showed a correlation between neuronal responses and perceptual judgment in near-preferring, but not far-preferring, units, mirroring the psychophysically measured strategy. After one monkey learned to weight near and far disparities equally, activity in its far-preferring neurons correlated with choice. Thus, the pattern of correlations between neuronal activity and perceptual reports indicates how subjects use their neuronal signals.