MRI and retinotopic mapping show that LGN activity in deaf participants is biased toward peripheral vision, with no significant difference in LGN volume between deaf and hearing groups.

The findings are published in the Proceedings of the National Academy of Sciences, with plans for future work to disentangle genetic and non-genetic contributions to these plastic changes.

Researchers suggest the enhanced peripheral vision may serve as an early warning system for detecting peripheral hazards in environments lacking auditory cues.

The strongest peripheral-vision enhancement and central-vision trade-off appear most pronounced in deaf individuals who learned British Sign Language as their first language.

Findings imply neural differences could originate upstream at the retina and may involve genetic factors, with some participants genetically deaf and others with unknown etiologies.

The peripheral-vision bias in deaf individuals is linked to compensatory plasticity from reduced auditory processing and may trade off diminished central-vision representations.

Adults with early, profound deafness show greater reliance on peripheral vision than hearing peers, indicating early reorganization of the visual pathway beginning at the LGN.

The study analyzed 16 deaf and 16 hearing adults using structural and functional MRI for retinotopic mapping, with brain boundaries cross-validated against standard atlases.

In V1, total cortical volume is similar across groups, but deaf individuals show a shift in surface-area distribution favoring peripheral over central representations.