Lateral Orientation, Eye Movements and Dichotic Listening

Pas, studies have found that lateral orientation (eye or head turn) may influence hemispheric asymmetry on the dichotic listening task. The present work studied the effects of forced head and eye turn on a consonant-vowel dichotic test. Spontaneous conjugate lateral eye movements (CLEM) in response to questions were also measured. The subjects were 29 male and 25 female right-handed university students. The dichotic test was administered using a forced-attention method rather than free recall in order to control for attentional bias. As predicted, right lookers on the CLEM test, showed an enhanced right ear advantage while left lookers showed a diminished right ear advantage. This suggests that characteristic hemispheric arousal may enhance or inhibit asymmetry on perceptual laterality tests. No relationship was found between dichotic listening and forced head or eye turning. It was noted that past experiments may have failed to control for the attentional bias introduced by having the head or eyes turned to one direction.