Unilateral forced nostril breathing affects dichotic listening for emotional tones Deborah M. Saucier, * Farzana Karim Tessem, Aaron H. Sheerin, and Lorin Elias Department of Psychology, University of Saskatchewan, Saskatoon, Sask., Canada S7N 5A5 Accepted 12 February 2004 Available online 13 April 2004 Abstract Unilateral forced nostril breathing (UFNB) through the left nostril is associated with enhanced spatial abilities, whereas UFNB through the right nostril is associated with enhanced verbal abilities. However, the effects of UFNB on standard tasks of laterality (e.g., dichotic listening) are unknown. This study employed dichotic listening for word targets, which typically exhibits a right ear advantage (REA), and dichotic listening for emotional targets, which typically exhibits a left ear advantage (LEA). Participants were asked to breathe either through their dominant nostril (congruent UFNB) or to breathe through their non-dominant nostril (in- congruent UFNB) for the entire testing session. There was a significant three-way interaction between the type of dichotic listening task, nostril dominance, and nostril assignment, with the expected REA for word targets and the expected LEA for emotional targets—with one exception. Right nostril dominant participants assigned to the congruent condition exhibited an LEA for emo- tional targets (p <:05). The other three groups exhibited the expected LEA/right hemisphere advantage for the detection of emotional targets and all groups exhibited the expected REA/left hemisphere advantage for detection of word targets. As such, possible bias induced by tactile stimulation of the contralateral face cannot account for these results. Thus, our data are consistent with a selective enhancement of right hemispheric lateralized functions by right nostril UFNB. Ó 2004 Elsevier Inc. All rights reserved. 1. Introduction Breathing solely one nostril or the other, referred to as unilateral forced nostril breathing (UFNB), may af- fect cognitive ability. For instance, breathing through the left nostril is associated with enhanced spatial abil- ities, whereas breathing through the right nostril is as- sociated with enhanced verbal abilities (Jella & Shannahoff-Khalsa, 1993). These effects have been ob- served for a variety of spatial and verbal tasks (e.g., Block, Arnott, Quigley, & Lynch, 1989) and as such, are thought to reflect a contralateral relationship between nostril and hemispheric function (Werntz, Bickford, & Shannahoff-Khalsa, 1987). Further, it is suggested that lateralized cognitive function can be enhanced by con- tralateral UFNB (Werntz et al., 1987). To date, no study of UFNB has examined the effects of UFNB on standard tasks of laterality (e.g., dichotic lis- tening). To investigate whether UFNB can affect lateral- ized cognitive ability, we conducted the following experiment using tasks with demonstrated lateralized hemispheric dominance—dichotic listening for word tar- gets, which typically exhibits a right ear advantage (REA), and emotional targets, which typically exhibits a left ear advantage (LEA; Bryden & MacRae, 1988). Further, most studies of UFNB may have inadvertently introduced some type of attentional bias, by forcibly oc- cluding their non-dominant contralateral nostril resulting in tactile stimulation of the contralateral side of the face. To investigate whether or not contralateral tactile stim- ulation affects the relationship between UFNB and lat- erality, approximately half of our participants performed UFNB with their non-dominant nostril. 2. Methods 2.1. Participants Sixty-seven participants (age M ¼ 20:73, SD ¼ 5:055) were recruited from the Department of PsychologyÕs * Corresponding author. Fax: +1-306-966-6630. E-mail address: deb.saucier@usask.ca (D.M. Saucier). 0278-2626/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.bandc.2004.02.059 Brain and Cognition 55 (2004) 403–405 www.elsevier.com/locate/b&c