Visual perception in adults with CP - assessment and individual differences: An exploratory study

Visual perception is frequently impaired in individuals with cerebral palsy (CP). Little is known about the range of visual perceptual impairments that may occur in adults with CP, and few studies have investigated performance at the individual level. Here, we aim to characterize visual perceptual functions in a group of adults with CP.

21 participants with CP and 40 neurotypical control participants, aged 18-40 years, were assessed with a range of visual perceptual tests commonly used in neuropsychological practice. The tests were selected to make sure that individuals with all severities of CP would be able to take part in the study. The analyses were pre-registered prior to data collection on Open Science Framework: https://doi.org/10.17605/OSF.IO/S7KBE. Results were analyzed both at the group level and at an individual level using single case methodology.

Most participants with CP were able to complete the full test battery, despite some having severe motor impairments. The participants with CP performed worse than the control group on indexes of face recognition, reading and visuospatial functions, while there was no difference on an object recognition index. At the individual level, three participants were impaired on ≤ 1 test, while 18 of 21 participants with cerebral palsy were impaired on more than two tests (range: 3-15).

Overall, adults with CP can have a wide range of visual perceptual impairments, even when evaluated using screening tests. The participants with impaired visual perceptual functions showed signs of both dorsal and ventral stream dysfunction.