Journal of Physiological Anthropology

35:8 (2016) DOI 10.1186/s40101-016-0089-3

Ji-Woo Seok, Jin-Hun Sohn and Chaejoon Cheong

Abstract

Background: Sexual behavior is an important role for the survival of species. The advancement of brain imaging
methods has enabled the understanding of the brain mechanism related to sexual arousal. The previous studies
on the brain mechanism related to sexual arousal have mostly conducted on block design paradigm.
Methods: Despite its requirement for stricter experimental control, the event-related paradigm is known to be
more efficient in detecting instant emotional and cognitive responses. The paradigm also enables the observation
of hemodynamic responses through time. Therefore, this study used the event-related fMRI to examine the brain
activation in various areas associated with sexual arousal as well as changes in hemodynamic responses with time.
Results: Strong activations were observed in the various areas associated with sexual arousal comprised of various
factors: (1) activation areas related to cognitive factors: the occipital lobe and parietal lobe; (2) activation areas related
to emotional factors: the thalamus and amygdala; (3) activation areas related to motivational factors: the anterior
cingulate gyrus, orbitofrontal cortex, and insula; and (4) activation areas related to physiological factors: the precentral
gyrus, putamen, and globus pallidus. We also identified the activation of the putamen and globus pallidus that were
not well observed in previous block design studies. In the result of the hemodynamic response, the neural activity in
those areas showed more transient aspects of the hemodynamic responses relative to the neural activity of other areas.
Conclusions: These results suggested that the event-related paradigm is better at detecting the neural activity of the
brain regions, which tend to appear suddenly, but disappear soon.