Evidence of hemispheric specialization in marmosets (Callithrix penicillata) using tympanic membrane thermometry

Abstract

Recent studies have employed tympanic thermometry to assess lateralization of cognitive and emotional functions in primates. However, no studies using this technique have investigated the possibility of hemispheric specialization in New World monkeys. Therefore, the aim of the present study was to investigate tympanic membrane (TM) temperature asymmetries and their possible correlation with stress responses in marmosets (Callithrix penicillata). Infrared TM thermometry was completed bilaterally in 24 animals (14 males and 10 females) during a stressful situation of capture and restraint. There were no significant differences between gender. A significant negative correlation was observed between TM temperature of the right ear and the number of captures (r = -0.633; P<0.001). Subjects with a more frequent previous history of captures (5 to 9 captures; N = 11) showed lower TM temperature when compared to those with fewer previous captures (1 to 4 captures; N = 13). No differences were observed for the left TM temperature. These results suggest that under intense emotional challenge (capture and restraint) there is a stronger activation of the neural structures situated in the right brain hemisphere. Taken together, the data reveal for the first time evidence of hemispheric specialization in emotional physiological processing in a New World monkey.

Comparison between tympanic and anal temperature with a clinical infrared ray thermometer in dogs

“…As it was suggested, the tympanic temperature reflects with confidence the degree of ipsilateral brain metabolism (Meiners and Dabbs, 1977;Boyce et al, 2002;Tomaz et al, 2003). However, it is not known to the certainty whether the gradient of the tympanic membrane temperature is related to an increased or diminished cerebral metabolism, due vasodilatation effects of the CO 2 (carbon dioxide) metabolism, and NO (nitric oxide) from the autonomic vascular reflex (Tomaz et al, 2003). Whatever be the interpretation, in dogs, seems to be sufficiently reliable the measurement of the anal temperature with a thermometer of emission of infra-red rays to evaluate the central body temperature.…”

Laterality as an indicator of emotional stress in ewes and lambs during a separation test

“…A strong directionality was found, especially in lambs, reflecting a dominance of one brain hemisphere over the other in decision-making processes. Previous studies have reported that the right hemisphere has a dominant role in processing responses to acute stress (Tomaz et al 2003;Mazzotti and Boere 2009). Handling and social isolation, both being common farm practices, are known to be a stressful event for gregarious animals such as sheep (Boissy et al 2005).…”

Dominance and stress signalling of carotenoid pigmentation in Arctic charr (Salvelinus alpinus): Lateralization effects?

“…For instance, in sheep social isolation stress is reduced by familiar faces and leads to increased activity in the right hemisphere [51], and strongly lateralized mothers had higher stress response than weakly lateralized mothers following separation from their young [52]. Further, stress induced temperature elevation in the right ear, corresponding to the right hemisphere, has been reported in marmosets [53] and cats [54]. Chronic stress causes neural damage in the right hemisphere in rats [55], and in humans suffering of major depressive disorders there is also a right hemisphere balance [56].…”