# Causal testing of the role of a place code for global-scale visual features in primate V1 using patterned optogenetics

> **NIH NIH F31** · UNIVERSITY OF TEXAS AT AUSTIN · 2021 · $37,718

## Abstract

Humans are highly sensitive to the overall shape of objects—a critical step in object identification. One hypothesis
is that the brain uses the shape of the spread of stimulus-evoked activity across the surface of visual cortex in
order to process shape, exploiting retinotopy—the well-documented organization of neurons as a projection of the
visual field across the surface of the cortex. Prior work from our group has found that the shape of activity across
the cortex holds information that can be used to decode the overall shape of a stimulus, but whether the brain
actually uses this information is as of yet unknown. The current proposal aims to test the hypothesis that the
shape of activity across the cortex can encode shape in vision by seeing if the perception of shape can
be brought about by artificially evoking shaped activity in visual cortex.
I will evoke this shaped neuronal activity using optogenetics, a technique for artificially exciting neurons using
light. By controlling the pattern of excitation light, I can control the shape of the activity I evoke. If I can use this
optogenetic stimulation to bias macaque monkeys performing a shape discrimination task to report seeing the
shapes corresponding to the artificially inserted activity, it would indicate that the brain relies on the retinotopic
shape of activity across the cortex to process shape in vision.
Experiments in Aim 1 will describe the behavior of macaques performing a simplified shape discrimination task
and the neuronal signals recorded as they perform the task, with detailed computational modeling of potential
neuronal strategies. Aim 2 will be focused on the development of the pipeline necessary for precise shaping
of optogenetically evoked activity. Aim 3 will be an experiment in which optogenetics will be used to introduce
artificial activity of a specific shape into the visual cortex of macaques performing the shape discrimination task.
I will see if behavior, and thus likely perception, is systematically affected by the addition of artificial neuronal
activity that only contains information by virtue of the shape of its spread across the cortex. The proposed work
will be an important contribution to our understanding of how shape is processed in vision and will have broad
implications for the utility of patterned optogenetic stimulation in translational contexts such as for use in cortical
neuroprostheses for restoring vision.

## Key facts

- **NIH application ID:** 10157768
- **Project number:** 1F31EY032423-01
- **Recipient organization:** UNIVERSITY OF TEXAS AT AUSTIN
- **Principal Investigator:** Shun Kobayashi
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $37,718
- **Award type:** 1
- **Project period:** 2021-01-16 → 2024-01-15

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10157768

## Citation

> US National Institutes of Health, RePORTER application 10157768, Causal testing of the role of a place code for global-scale visual features in primate V1 using patterned optogenetics (1F31EY032423-01). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10157768. Licensed CC0.

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