Affiliations: Centre de Neurosciences de la Cognition and Department
of Psychology, Université du Québec à Montréal, Canada | Department of Psychology, Université du Québec à
Trois Rivières, Canada
Abstract: Brain topographical studies of normal men have have shown that
sexual excitation is asymmetric in the brain hemispheres. Group studies of
patients with unilateral epileptic foci and other studies of patients with
unilateral brain lesions have come to the same conclusion. The present study
reviewed previously published single case reports of patients with frank hypo
or hypersexuality subsequent to a unilateral brain lesion. Hyposexual patients
tended to have left hemisphere lesions (primarily of the temporal lobe), and
hypersexual patients tended to have right hemisphere lesions (primarily of the
temporal lobe) (p < 0.05). We interpret this double dissociation as part of
a more general phenomenon of psychic tone similarly dissociated with
regard to hemispheric control, including mood, psychomotor baseline, speech
rate, and even immunity. The behavioral significance of this psychic tone
is to modulate approach versus avoidance behavior.
