Time-of-day-induced priming effects on verbal and nonverbal dichotic tasks in male and female adult subjects.

Abstract

Normal adults (32 males and 32 females) were tested for time-of-day related shifts in laterality and priming on two dichotic listening tasks using consonant-vowel combinations (CVs) and musical melodies. The predicted time-of-day effect on melodies was due to males showing low report in the morning, but not the afternoon, suggesting increased right hemisphere involvement in the afternoon. A time-of-day-induced priming effect on the laterality index for CVs differentiated males and females. Males tested morning-first were more lateralized than females, who in turn were more lateralized when tested afternoon-first. A time-of-day-induced priming effect on the laterality index for music indicated those tested afternoon-first showed an overall left ear advantage (LEA), whereas those tested morning-first showed an overall right ear advantage (REA). On raw music scores a sex-linked, time-of-day-induced priming effect was due to the prior presentation of CVs--that is, cognitive priming. Other priming effects on music were evident for order of stimulus presentation and order of ear attended. Implications for theory, research and pedagogy are discussed.