# Probing the time scales of perceptual readout with white noise optogenetic inhibition

> **NIH NIH R21** · UNIVERSITY OF CHICAGO · 2021 · $246,000

## Abstract

Project Abstract
During visually guided behaviors, only hundreds of milliseconds elapse between a sensory stimulus and its
ensuing action, yet spiking responses across sensorimotor circuits come to represent stimulus features and
guide forthcoming actions. Owing to the immense complexity of brain circuits, there is great uncertainty as to
which spikes (and in which brain areas) causally contribute to behavior. We need methods capable of resolving
how moment-to-moment fluctuations in spiking drive perception and action. A versatile tool for examining
relationships between sensory input and spiking or behavior is white noise analysis. A random, dynamic
stimulus is presented and these fluctuations can be leveraged to generate unbiased estimates of the stimulus
features that drive neuronal spiking (spike-triggered average) or the periods of sensory input that drive
perceptual decisions (psychophysical kernel). We have adapted white noise analysis for optogenetic
stimulation. We deliver random patterns of weak optogenetic inhibition to visual areas during behavior and
calculate the average optogenetic signal associated with perceptual reports (hits, misses). Our preliminary data
show that white noise optogenetic inhibition rapidly yields kernels that define the contribution of spiking in
specific neuronal populations to specific behaviors, with a resolution of a tens of milliseconds (optogenetic
behavioral kernel, OBK). Such precise timing information would be impractical to obtain with standard
optogenetic approaches (e.g., pulses or sustained inhibition). We will validate and apply this approach by
determining how OBKs measured in lower and higher visual areas depend on visual input and task demands,
and in doing so generate new observations that link patterns of spiking with perceptual decisions throughout
the visual brain. Mice will be trained to work reliably at threshold in perceptual tasks. In the first experiment,
visual information will arrive suddenly (super-threshold intensity, contrast steps) or gradually (near-threshold,
contrast ramps) and we will relate OBKs to changes in the distributions of stimulus-evoked spikes. In the
second experiment, mice will be required to respond to a target orientation and reject distractors. We will
measure OBKs in both cortical (striate and extrastriate visual areas) and subcortical (superior colliculus) visual
areas to determine the time course of their respective contributions to task performance. A subset of mice will
also be implanted with fixed-wire optrodes to facilitate concurrent electrophysiological recordings and
optogenetic perturbations during behavior. These data will relate moment-to-moment reductions in stimulus
and/or task-evoked spikes with perceptual reports and enable comparisons between population spiking and
OBKs. This work will provide unprecedented resolution into the periods of neuronal activity in cortical and
subcortical visual pathways that causally contribute to perception and b...

## Key facts

- **NIH application ID:** 10195009
- **Project number:** 1R21EY032650-01
- **Recipient organization:** UNIVERSITY OF CHICAGO
- **Principal Investigator:** Jackson Jordan Cone
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $246,000
- **Award type:** 1
- **Project period:** 2021-05-01 → 2023-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10195009

## Citation

> US National Institutes of Health, RePORTER application 10195009, Probing the time scales of perceptual readout with white noise optogenetic inhibition (1R21EY032650-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10195009. Licensed CC0.

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