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.

Key Words:

• Time-of-day
• circadian rhythms
• dichotic listening
• music
• priming effects
• neuropsychology