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Author (up) Dunbar, R.I.M.
Title Male and female brain evolution is subject to contrasting selection pressures in primates Type Journal Article
Year 2007 Publication BMC Biology Abbreviated Journal BMC Biol
Volume 5 Issue Pages 21
Keywords Animals; *Brain/physiology; *Evolution; Female; Humans; Male; *Selection (Genetics); *Sex Characteristics
Abstract The claim that differences in brain size across primate species has mainly been driven by the demands of sociality (the “social brain” hypothesis) is now widely accepted. Some of the evidence to support this comes from the fact that species that live in large social groups have larger brains, and in particular larger neocortices. Lindenfors and colleagues (BMC Biology 5:20) add significantly to our appreciation of this process by showing that there are striking differences between the two sexes in the social mechanisms and brain units involved. Female sociality (which is more affiliative) is related most closely to neocortex volume, but male sociality (which is more competitive and combative) is more closely related to subcortical units (notably those associated with emotional responses). Thus different brain units have responded to different selection pressures.
Address British Academy Centenary Research Project, School of Biological Sciences, University of Liverpool, Liverpool, UK. rimd@liv.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1741-7007 ISBN Medium
Area Expedition Conference
Notes PMID:17493267 Approved no
Call Number Serial 2100
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Author (up) Scheumann, M.; Zimmermann, E.
Title Sex-specific asymmetries in communication sound perception are not related to hand preference in an early primate Type Journal Article
Year 2008 Publication BMC Biology Abbreviated Journal
Volume 6 Issue 1 Pages 3
Keywords
Abstract BACKGROUND:Left hemispheric dominance of language processing and handedness, previously thought to be unique to humans, is currently under debate. To gain an insight into the origin of lateralization in primates, we have studied gray mouse lemurs, suggested to represent the most ancestral primate condition. We explored potential functional asymmetries on the behavioral level by applying a combined handedness and auditory perception task. For testing handedness, we used a forced food-grasping task. For testing auditory perception, we adapted the head turn paradigm, originally established for exploring hemispheric specializations in conspecific sound processing in Old World monkeys, and exposed 38 subjects to control sounds and conspecific communication sounds of positive and negative emotional valence.RESULTS:The tested mouse lemur population did not show an asymmetry in hand preference or in orientation towards conspecific communication sounds. However, males, but not females, exhibited a significant right ear-left hemisphere bias when exposed to conspecific communication sounds of negative emotional valence. Orientation asymmetries were not related to hand preference.CONCLUSION:Our results provide the first evidence for sex-specific asymmetries for conspecific communication sound perception in non-human primates. Furthermore, they suggest that hemispheric dominance for communication sound processing evolved before handedness and independently from each other.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1741-7007 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5369
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