Does erotic stimulus presentation design affect brain activation patterns? Event-related vs. blocked fMRI designs

Mira Bühler¹^,2 , Sabine Vollstädt-Klein² , Jane Klemen³ and Michael N Smolka⁴

¹Behavioural & Clinical Neuroscience Institute, Department of Experimental Psychology, University of Cambridge, Downing Site, Cambridge, CB2 3EB, UK

²Central Institute of Mental Health, Department of Addictive Behavior and Addiction Medicine, J5, 68159, Mannheim, Germany

³NeuroImage Nord, Department of Systems Neuroscience, University Medical Centre Hamburg Eppendorf, Martinistr, 52, 20246, Hamburg, Germany

⁴Section of Systems Neuroscience, Department of Psychiatry and Psychotherapy, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Germany

author email corresponding author email

Behavioral and Brain Functions 2008, 4:30doi:10.1186/1744-9081-4-30


Published:	22 July 2008

Abstract

Background

Existing brain imaging studies, investigating sexual arousal via the presentation of erotic pictures or film excerpts, have mainly used blocked designs with long stimulus presentation times.

Methods

To clarify how experimental functional magnetic resonance imaging (fMRI) design affects stimulus-induced brain activity, we compared brief event-related presentation of erotic vs. neutral stimuli with blocked presentation in 10 male volunteers.

Results

Brain activation differed depending on design type in only 10% of the voxels showing task related brain activity. Differences between blocked and event-related stimulus presentation were found in occipitotemporal and temporal regions (Brodmann Area (BA) 19, 37, 48), parietal areas (BA 7, 40) and areas in the frontal lobe (BA 6, 44).

Conclusion

Our results suggest that event-related designs might be a potential alternative when the core interest is the detection of networks associated with immediate processing of erotic stimuli.

Additionally, blocked, compared to event-related, stimulus presentation allows the emergence and detection of non-specific secondary processes, such as sustained attention, motor imagery and inhibition of sexual arousal.