Beyond the eye: Cortical differences in primary visual processing in children with cerebral palsy

•Visual processing deficits are common in children with CP.•MEG was used to image multispectral cortical oscillations during visual processing.•Compared with controls, children with CP had weaker occipital oscillations.•Aberrant cortical oscillations likely impact early visual processing abilities. Despite the growing clinical recognition of visual impairments among people with cerebral palsy (CP), very few studies have evaluated the neurophysiology of the visual circuitry. To this end, the primary aim of this investigation was to use magnetoencephalography and beamforming methods to image the relative change in the alpha–beta and gamma occipital cortical oscillations induced by a spatial grating stimulus (e.g., visual contrast) that was viewed by a cohort of children with CP and typically-developing (TD) children. Our results showed that the high-contrast, visual gratings stimuli induced a decrease in alpha–beta (10 – 20 Hz) activity, and an increase in both low (40 – 56 Hz) and high (60 – 72 Hz) gamma oscillations in the occipital cortices. Compared with the TD children, the strength of the frequency specific cortical oscillations were significantly weaker in the children with CP, suggesting that they had deficient processing of the contrast stimulus. Although CP is largely perceived as a musculoskeletal centric disorder, our results fuel the growing impression that there may also be prominent visual processing deficiencies. These visual processing deficits likely impact the ability to perceive visual changes in the environment.