# Adaptation and visual coding

> **NIH NIH R01** · UNIVERSITY OF NEVADA RENO · 2022 · $346,025

## Abstract

Project summary
Vision is a highly dynamic system that continuously adapts to changes in the stimulus properties of the
environment or the physiological properties of the observer. How these adaptation processes adjust to the
sensitivity limits of the observer is important for understanding normal visual function and the consequences of
visual deficits or disease. The proposed research examines basic mechanisms of adaptation and plasticity by
examining how color vision adjusts to losses in color sensitivity as a result of inherited color deficiencies. Color-
deficient observers with anomalous trichromacy have weaker sensitivity to reddish-greenish colors because of
alterations in the genes coding the medium and longwave photopigments. However, there is emerging
evidence that the perceptual experience of color in anomalous trichromats is stronger than their sensitivity
losses predict, potentially because the neural mechanisms encoding color amplify and thus compensate for the
reduced color signals available from their receptors. Color deficiencies provide an ideal model for exploring
these compensatory mechanisms, by comparing observers who differ because of well-defined and highly
stable properties of the initial receptors, for which they have had a lifetime to adapt. The proposed studies are
designed to assess the extent and mechanisms of these compensatory adjustments and how they are
manifest in and impact different aspects of color perception. The first aim will compare color perception and
contrast coding in normal and color-deficient observers across a battery of tasks designed to isolate different
levels and properties of color vision. The second aim will complement these behavioral assessments with
direct measures of cortical neural activity in normal and color-anomalous observers using functional magnetic
resonance imaging, electroencephalography, and adaptive optics to probe neural responses to color. The
results of these studies will serve to better characterize the neural and perceptual consequences of color
deficiencies, and more generally will characterize basic processes underlying human vision and how it adapts
in response to visual losses or their corrections.

## Key facts

- **NIH application ID:** 10399443
- **Project number:** 5R01EY010834-21
- **Recipient organization:** UNIVERSITY OF NEVADA RENO
- **Principal Investigator:** MICHAEL A WEBSTER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $346,025
- **Award type:** 5
- **Project period:** 1994-12-01 → 2024-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10399443

## Citation

> US National Institutes of Health, RePORTER application 10399443, Adaptation and visual coding (5R01EY010834-21). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10399443. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*