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bioRxiv · 10.1101/2020.06.24.167213

Amplitude modulations of sensory responses, and deviations from Weber's Law in pulsatile evidence accumulation

Koay, S. A.·Thiberge, S. Y.·Brody, C. D.·Tank, D. W.
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Abstract

How do animals make behavioral decisions based on noisy sensory signals, which are moreover a tiny fraction of ongoing activity in the brain? Some theories suggest that sensory responses should be accumulated through time to reduce noise. Others suggest that feedback-based gain control of sensory responses allow small signals to be selectively amplified to drive behavior. We recorded from neuronal populations across posterior cortex as mice performed a decision-making task based on accumulating randomly timed pulses of visual evidence. Here we focus on a subset of neurons, with putative sensory responses that were time-locked to each pulse. These neurons exhibited a variety of amplitude (gain-like) modulations, notably by choice and accumulated evidence. These neural data inspired a hypothetical accumulation circuit with a multiplicative feedback-loop architecture, which parsimoniously explains deviations in perceptual discrimination from Weber-Fechner Law. Our neural observations thus led to a model that synthesizes both accumulation and feedback hypotheses.

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Koay, S. A., Thiberge, S. Y., Brody, C. D., Tank, D. W.. 2020-06-29. Amplitude modulations of sensory responses, and deviations from Weber's Law in pulsatile evidence accumulation. https://doi.org/10.1101/2020.06.24.167213

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