The role of anterior and posterior insula in male genital response and in visual attention: an exploratory multimodal fMRI study

Abstract

Several studies highlighted the role of insula on several functions and in sexual behavior. This exploratory study examines the relationships among genital responses, brain responses, and eye movements, to disentangle the role played by the anterior and posterior insula during different stages of male sexual response and during visual attention to sexual stimuli. In 19 healthy men, fMRI, eye movement, and penile tumescence data were collected during a visual sexual stimulation task. After a whole-brain analysis comparing neutral and sexual clips and confirming a role for the bilateral insulae, we selected two bilateral seed regions in anterior and posterior insula for functional connectivity analysis. Single-ROI-GLMs were run for the FC target regions. Single-ROI-GLMs were performed based on areas to which participants fixate: “Faces”, “Genitals,” and “Background” with the contrast “Genitals > Faces”. Single-ROI-GLMs with baseline, onset, and sustained PT response for the sexual clips were performed. We found stronger effects for the posterior than the anterior insula. In the target regions of the posterior insula, we found three different pathways: the first involved in visual attention, onset of erection, and sustained erection; the second involved only in the onset of erection, and the third limited to sustained erection.

Breath chemical markers of sexual arousal in humans

“…This interpretation is consistent with findings that sexual stimuli attract attention more than other emotional stimuli 35 , 36 . In addition, recent findings using eye-tracking measures indicated that individuals tend to have fewer but longer eye fixations during exposure to sexual films compared to neutral clips 37 , 38 , suggesting a stronger attentional focus to erotic cues that may be related to cognitive processing of sexual stimuli. Therefore, although breath isoprene can be a potentially useful marker of sexual arousal, caution is advised as it is also strongly dependent on hemodynamic and respiratory parameters such as cardiac output and pulmonary ventilation which in turn are highly variable depending on several factors (e.g.…”

“…The film was chosen from a database of the Portuguese SexLab based on the high levels of sexual arousal elicited in men and women. The film was successfully used in previous research to induce sexual arousal 37 and was primarily selected based on the findings of a pilot study where a sample of men and women rated the most sexually arousing clips from a total of 10. The anxiety-inducing film was a 10-min clip from the Russian roulette scene of The Deer Hunter (Cimino, 1978).…”

The reproductive functions of the human brain regions: A systematic review

“…Its outer grey-coloured surface (cerebral cortex) is responsible for the neuronal computations underlying complex phenomena, such as perception, thought, language, attention, episodic memory and voluntary movement. [ 29 ] The studies,[ 14 15 17 ] on the prospective roles of the cerebrum on the human reproductive system utilised neuronal stimulation of the cerebrum. Komisaruk et al [ 15 ] mapped the female genitals in the sensory cortex using functional magnetic resonance imaging.…”

“…[ 16 ] The insula (part of the cerebrum) was involved in controlling male genital response and visual attention. [ 17 ] The studies on melatonin supplementation affecting the pineal gland (body) reported improvements in oocyte and embryo quality,[ 18 19 ] re-balancing of intrafollicular oxidative stress level in infertile participants[ 20 ] and the prevention of maternal endothelial pro-oxidant injury. [ 21 ] A low level of melatonin was correlated with oxidative stress biomarkers, which could be involved in infertility.…”

The brain activation-based sexual image classifier (BASIC): a sensitive and specific fMRI activity pattern for sexual image processing

“…The posterior insula is held to be important for somatosensory representations, multisensory information, and pleasant touch ( Olausson et al. 2002 ; Cera et al. 2020 ).…”