Stimulus-dependent relationships between behavioral choice and sensory neural responses

Understanding perceptual decision-making requires linking sensory neural responses to behavioral choices. In two-choice tasks, activity-choice covariations are commonly quantified with a single measure of choice probability (CP), without characterizing their changes across stimulus levels. We provide theoretical conditions for stimulus dependencies of activity-choice covariations. Assuming a general decision-threshold model, which comprises both feedforward and feedback processing and allows for a stimulus-modulated neural population covariance, we analytically predict a very general and previously unreported stimulus dependence of CPs. We develop new tools, including refined analyses of CPs and generalized linear models with stimulus-choice interactions, which accurately assess the stimulus- or choice-driven signals of each neuron, characterizing stimulus-dependent patterns of choice-related signals. With these tools, we analyze CPs of macaque MT neurons during a motion discrimination task. Our analysis provides preliminary empirical evidence for the promise of studying stimulus dependencies of choice-related signals, encouraging further assessment in wider data sets.

Automated summary

This study investigates the perceptual decision-making process by exploring the stimulus dependencies of activity-choice covariations. The authors provide theoretical conditions for understanding how sensory neural responses are linked to behavioral choices, and develop new tools to assess the stimulus-driven signals of each neuron accurately. The analysis on macaque MT neurons during a motion discrimination task offers preliminary empirical evidence for studying the stimulus dependencies of choice-related signals, encouraging further research in wider data sets.