# Functional connectivity in primary visual cortex

> **NIH NIH R01** · STATE COLLEGE OF OPTOMETRY · 2021 · $392,850

## Abstract

PROJECT SUMMARY
All animals that can form images in their retinas, from flies to humans, need ON and OFF brain pathways to
process light and dark features in visual scenes. The traditional textbook view is that these ON and OFF
pathways fully converge in visual cortex to make neurons selective to stimulus orientation but invariant to
stimulus polarity and spatial phase. Against this traditional view, our recent work demonstrates that ON and OFF
pathways segregate in visual cortex, specialize in different spatiotemporal functions, and process images
relatively independently from each other. In addition, our preliminary results indicate that ON and OFF cortical
pathways respond very differently to changes in luminance range, which varies continuously in our visual
environment from sunrise to sunset. Based on our results, we hypothesize that luminance perception originates
from the interaction between two separate and relatively independent ON and OFF pathways that are exquisitely
matched to the statistics of light and dark features in natural scenes. This new understanding of ON and OFF
cortical processing has important implications for human luminance perception, image brain processing analysis
and could help improve the diagnostic tools available to manage treatment in human visual disease. In this
proposal, we will investigate how ON and OFF cortical pathways interact to generate luminance perception, and
how these interactions vary with background luminance, luminance range and the rod/cone retinal ratio available
to sample the images. We will then use all these measurements to develop models that replicate human
luminance perception more accurately than in the past and new diagnostic tools that measure human ON and
OFF visual function in diseases that affect the retina (e.g. glaucoma) and visual cortex (e.g. amblyopia).

## Key facts

- **NIH application ID:** 10231146
- **Project number:** 5R01EY005253-35
- **Recipient organization:** STATE COLLEGE OF OPTOMETRY
- **Principal Investigator:** Jose Manuel Alonso
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $392,850
- **Award type:** 5
- **Project period:** 1983-07-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10231146

## Citation

> US National Institutes of Health, RePORTER application 10231146, Functional connectivity in primary visual cortex (5R01EY005253-35). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10231146. Licensed CC0.

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