Excessive Neural Responses and Visual Discomfort

Spatially and temporally periodic patterns can look aversive to some individuals (Wilkins et al, 1984, Brain, 107, 989-1017), especially clinical populations such as migraine (Marcus and Soso, 1989, Arch Neurol., 46(10), 1129-32) epilepsy (Wilkins, Darby and Binnie, 1979, Brain, 102, 1-25). It has been suggested that this might be due to excessive neural responses (Juricevic, Land, Wilkins and Webster, 2010, Perception, 39(7), 884-899). Spatial frequency content has been shown to affect both relative and absolute discomfort judgements for spatially periodic riloid stimuli (Clark, O'Hare and Hibbard, 2013, Perception, ECVP Supp.; O'Hare, Clark and Hibbard, 2013, Perception ECVP Supplement). The current study investigated the possibility of whether neural correlates of visual discomfort from periodic stimuli could be measured using EEG. Stimuli were first matched for perceived contrast using a self adjustment task. EEG measurements were then obtained, alongside subjective discomfort judgements. Subjective discomfort judgements support those found previously, under various circumstances, indicating that spatial frequency plays a role in the perceived discomfort of periodic images. However, trends in EEG responses do not appear to have a straightforward relationship to subjective discomfort judgements