Task effects and individual differences in the study of lateral eye movements

Twenty-nine males and 29 females (all right-handed) participated in this study. The effects of question type (numerical, verbal, spatial) and experimenter position (in front of or behind the subject) on direction of lateral eye movements (LEMs) were tested. Also the relation between dominant LEM direction and other individual traits was investigated. The percentage of LEMs (tonic changes) as well as the first LEM (phasic changes) in the reflective period was scored. Results were identical for both methods; there were no task-specific effects demonstrated, nor was a relation found between dominant LEM direction and imagery, extraversion, neuroticism, sensation seeking, impulsiveness, and amount of somatic and psychic complaints. It appeared that the extent to which subjects gazed away varied with the amount of stress that was induced, while the direction of glance depended on the individual habit of the subject. The conclusion was that LEMs are subject specific rather than task specific and that this individual specificity is strengthened under stress conditions.