Brain activation and sexual arousal in healthy, heterosexual males -- Arnow et al. 125 (5): 1014 -- Brain
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Summary
Introduction
Material and methods
Results
Discussion
References
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Despite
the brain’s central role in sexual function, little is known about relationships between
brain activation
and sexual response. In this study, we employed functional MRI (fMRI) to examine relationships between
brain activation
and sexual
arousal in a group
of young, healthy, heterosexual males. Each subject was exposed to two sequences
of video material consisting
of explicitly erotic (E), relaxing (R)
and sports (S) segments in an unpredictable order. Data on penile turgidity was collected using a custom-built pneumatic pressure cuff. Both traditional block analyses using contrasts between sexually arousing
and non-arousing video clips
and a regression using penile turgidity as
the covariate
of interest were performed. In both types
of analyses, contrast images were computed for each subject
and these images were subsequently used in a r
andom effects analysis. Strong activations specifically associated with penile turgidity were observed in
the right subinsular region including
the claustrum, left caudate
and putamen, right middle occipital/ middle temporal gyri, bilateral cingulate gyrus
and right sensorimotor
and pre-motor regions. Smaller, but significant activation was observed in
the right hypothalamus. Few significant activations were found in
the block analyses. Implications
of the findings are discussed. Our study demonstrates
the feasibility
of examining
brain activation/sexual response relationships in an fMRI environment
and reveals a number
of brain structures whose activation is time-locked to sexual
arousal.
Keywords:
brain activation
and sexual response; functional MRI; right insula/subinsular region; claustrum; striatum
Abbreviations: BA= Brodmann area; MNI = Montreal Neurological Institute; rCBF = regional cerebral blood flow; SPM99 = statistical parametric mapping (1999 s
oftware version)