Eye fixation related potentials in a proof reading task

The eye fixation related potential (EFRP) associated with the occurrence of fixation pauses can be obtained by averaging EEGs at termination of saccad es. EFRP is a kind of ERP measurable at the eye movement situation. Variati ons of EFRP were examined during a proof reading task for a long time. Two paragraphs of sentences were presented on the left and the right sides of a CRT. The paragraph on one side had some irrelevant words. Ten subjects wer e asked to detect the irrelevant words. The task started at 09.20 h and fin ished at 16.00 h and consisted of five blocks. The duration of each block w as I-h task and 10-min rest including a lunch (70 min). EEG and EOG were re corded during the task. EEGs were averaged at termination of saccades to ob tain EFRP. EFRP showed little changes during the morning blocks. However, t he mean amplitude between 100 and 200 ms of the positive component in the l ast two blocks decreased significantly compared with other blocks. The erro r rate, the performance and the score of fatigue increased at the end of th e task. EFRP would reflect decline of mental concentration (i.e. carelessne ss) caused by visual fatigue. (C) 2001 Elsevier Science B.V. All rights res erved.