Investigation of cue-based vertical and horizontal eye movements with electroencephalographic and eye-tracking data

OBJECTIVE This study investigates the influence of eye movement direction on patterns of brain activation. METHODS The processing of visual input was investigated by quantifying event-related desynchronization (ERD) in the electroencephalogram (EEG). Cue-based vertical and horizontal eye movements were measured with an eye tracker. Differences between vertical and horizontal eye movements in EEG and eye-tracking data were analyzed. RESULTS The results of this study indicate that vertical and horizontal eye movements result in different ERD and ERS patterns. During the execution of a saccade vertical eye movements are accompanied by a stronger ERS whereas the fixation of the cue is related to stronger ERD after horizontal eye movements. CONCLUSION The fact that eye movements are correlated with a desynchronization of activity in parietal and occipital areas is reasonable, since visual information processing and visual control of movements take place there. Stronger ERD in the alpha band could be related to the fact that information processing tasks like e.g. reading require mostly horizontal and not vertical eye movements. SIGNIFICANCE The differences in the ERD/ERS patterns in relation to the direction of the eye movement should be considered in future investigations and taken into account in the construction of paradigms.