Resting-state functional connectivity within the reward system mediates subcortical integration during erotic stimulus processing.

Abstract

Objectives: Erotic stimuli lead to activations in various brain regions, including the reward system. Several neuroimaging studies have investigated neurofunctional activations during visual erotic stimulation. Little research has investigated whether these functional activations are characterised by an intrinsic network architecture in the resting-state.

Methods: We therefore examined 37 healthy male heterosexual subjects by combining resting-state and task-related fMRI. In task-related fMRI, we used an established video clip task (erotic and non-erotic video clips). Vectors comprising different neuronal activations during the processing of visual erotic stimuli were then correlated with the strength of resting-state functional connectivity between two core regions of the human reward system (NAcc and midbrain).

Results: We observed an increase in neurofunctional activations in cortical and subcortical regions previously described in task-based fMRI studies during visual erotic stimulation. Increased rs-FC between midbrain and NAcc was associated with higher differential neuronal responsiveness in subcortical regions, particularly in the hypothalamus, thalamus and periaqueductal grey.

Conclusion: Our results support the role of the mesolimbic reward pathway in the processing of erotic stimuli. In particular they show that a higher rs-FC between midbrain and NAcc facilitates the simultaneous activation of subcortical brain regions that are relevant for the integration of processes in sexual behaviour.