Behavioural & Clinical Neuroscience Institute, Department of Experimental Psychology, University of Cambridge, Downing Site, Cambridge, CB2 3EB, UK.
Behav Brain Funct. 2008 Jul 22;4:30. doi: 10.1186/1744-9081-4-30.
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.
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.
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).
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.
现有的通过呈现色情图片或电影片段来研究性唤起的脑成像研究主要使用了具有长刺激呈现时间的块设计。
为了阐明实验功能磁共振成像（fMRI）设计如何影响刺激引起的大脑活动，我们比较了 10 名男性志愿者中短时间的事件相关呈现与块呈现的色情与中性刺激。
仅在 10%的显示任务相关大脑活动的体素中，设计类型会导致大脑激活不同。在枕颞和颞区（Brodmann 区 19、37、48）、顶区（BA7、40）和额叶区（BA6、44）发现了块呈现和事件相关刺激呈现之间的差异。
我们的结果表明，当核心兴趣是检测与色情刺激的即时处理相关的网络时，事件相关设计可能是一种潜在的替代方案。此外，与事件相关的刺激呈现相比，块呈现允许出现和检测非特定的次要过程，如持续注意力、运动想象和性唤起的抑制。
