Conjugated lateral eye movements and EEG: a study on schizophrenic and depressive patients

Body asymmetry affects conjugate lateral eye movement

A. H. Baker (1989) and A. H. Baker and A. I. Ledner (1990) reported that asymmetrical visual stimulation affects conjugate lateral eye movement (CLEM). In the present article, the authors explored whether asymmetrical body position similarly affects CLEM. The authors assessed CLEMs twice in a counterbalanced design. In the control (symmetric) condition, each participant sat in a completely symmetrical position facing a wall devoid of any asymmetrical features. In the experimental (asymmetrical) condition, half the participants rotated their heads 68 degrees clockwise relative to their bodies to face the experimenter, and the other half rotated their heads 68 degrees counterclockwise, also to face the experimenter. CLEM was predominantly toward the body's position in the asymmetrical condition rather than toward the body's position in the symmetrical condition.

Generality and specificity of emotion-recognition deficit in schizophrenic patients with positive and negative symptoms

Schizophrenic patients with positive and negative symptoms, as well as non-patient control subjects, were asked to recognize emotional stimuli of happy, sad, and neutral facial expressions. Dependent measures were the percentage of correct responses, and the incorrect use of an emotion category owing to false recognition. Schizophrenic patients with negative symptoms exhibited a generalized emotion-recognition deficit, and their use of emotion categories during false recognition was random. Schizophrenic patients with positive symptoms showed a deficit in their recognition of 'sad' emotion and were 'positively biased' to the category 'happy' as reflected by its most frequent usage during false recognition.

Task-specific conjugate lateral eye movements

Conjugate lateral eye movements induced by task-specific reflective thought were examined in 10 dextral men. Verbal and spatial stimuli designed to activate reflective thought in the left (verbal) and right (spatial) cerebral hemispheres of the brain were presented tachistoscopically in a darkened environment. Eye movements during reflective thought were monitored and scored using an infrared eye-tracking device. Reflective thought induced by the spatial task produced significantly more leftward conjugate lateral eye movement. The verbal task tended to produce more rightward and upward movements. The results are viewed as consistent with a task-specific brain-hemispheric activation model of contralateral conjugate eye movements during reflective thought.