Brain plasticity in amblyopia – ‘lazy eye’

Using high-resolution functional MRI, this study reveals that brain regions responsible for visual processing operate under a competitive, "use-it-or-lose-it" dynamic known as developmental rivalry.

In typical vision, cortical territory is balanced across specialized modules that process depth (binocular disparity), colour, and motion. However, in individuals with amblyopia (‘lazy eye’), the brain area dedicated to processing 3D depth vision shrinks significantly due to impaired input.

Rather than leaving this cortical space inactive, the neighbouring modules for motion and colour expand into the underutilised territory while preserving their overall structural layout. A similar inverse relationship between depth-processing area and colour or motion-processing area was observed even in individuals with normal vision.

These findings demonstrate that early visual pathways actively compete for brain real estate during development, allowing undamaged sensory capabilities to take over regions originally reserved for compromised functions.

Publication

Nasr, S., Skerswetat, J., Kennedy, B., Schmidt, M. E., Gaier, E. D., Morland, A. B., Bex, P., & Hunter, D. G. (2026). Mesoscale developmental rivalry in the human extrastriate visual cortex. Proceedings of the National Academy of Sciences of the United States of America, 123(28), e2600746123.

Lead researcher

Professor Tony Morland, Department of Psychology