# Neural mechanisms of long-term plasticity in human visual cortex

> **NIH NIH F32** · UNIVERSITY OF MINNESOTA · 2021 · $52,224

## Abstract

Summary
Neuroplasticity is key to rehabilitation from visual deficits. Yet, visual neural plasticity in adults
remains poorly understood. This is especially true in primary visual cortex (V1), where methods for
producing long-lasting adult neural plasticity have yet to be thoroughly established. The proposed
research aims to overcome this roadblock by investigating the neural bases of the McCollough Effect
(ME), a visual illusion produced by viewing colored, oriented patterns that causes black and white
patterns to appear colorful. The ME can endure for weeks, indicating that it produces long-lasting
changes in the visual system. The neural loci and mechanisms producing it remain under debate,
however. Behavioral work suggests that the ME likely arises at a very early level of visual processing.
However, past neuroimaging results have failed to support this claim, and the specific neural
subpopulations that produce ME have yet to be identified. The current proposal contains a
comprehensive investigation of the ME using fMRI to clarify its poorly understood neural bases. In
Aim 1, multivariate pattern analysis will test whether neural populations underlying the ME are located
in V1. A classifier will be trained to distinguish patterns of activity in V1 arising from black and white
vs colorful patterns, using data gathered prior to induction of the ME. If V1 is the locus of the ME, then
following its induction, the same classifier should categorize responses to black and white patterns as
colorful, matching perception. Aim 2 will use ultra-high-resolution fMRI to test whether effects of an
ME induced in one eye localize to ocular dominance columns containing neurons selective for that
eye, as suggested by behavioral work. The high-resolution data will be further characterized using a
forward modeling technique that disentangles the relative responses and gain changes of different
color-sensitive neural populations. Together, these experiments will test the hypothesis that the
McCollough Effect arises from gain changes in populations of eye- and color- selective
neurons in V1, demonstrating feed-forward neural plasticity in adult primary visual cortex. This
work is part of a research training and career development plan for Dr. Katherine E.M. Tregillus,
conducted at the University of Minnesota under the co-sponsorship of Dr. Stephen Engel and Dr.
Cheryl Olman. The work is a logical extension of previous research from the three investigators, and
the University of Minnesota provides an ideal environment for carrying it out. The proposed research
will advance understanding of neuroplasticity and provide the basis for the applicant’s independent
career, where she intends to translate her work on long-term adaptation to clinical applications. For
example, paradigms similar to the ME could be developed to balance the gain of the two eyes in
amblyopia, or to improve the gain of color-opponent signals in color anomalous observers.

## Key facts

- **NIH application ID:** 10226856
- **Project number:** 5F32EY031178-02
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** Katherine Elizabeth Mussell Tregillus
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $52,224
- **Award type:** 5
- **Project period:** 2020-08-26 → 2022-05-03

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10226856

## Citation

> US National Institutes of Health, RePORTER application 10226856, Neural mechanisms of long-term plasticity in human visual cortex (5F32EY031178-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10226856. Licensed CC0.

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