Institute of Clinical Psychology and Psychotherapy, Department of Psychology, Technische Universität Dresden, Dresden, Germany.
PLoS One. 2013 Aug 15;8(8):e72576. doi: 10.1371/journal.pone.0072576. eCollection 2013.
It has been repeatedly shown that functional magnetic resonance imaging (fMRI) triggers distress and neuroendocrine response systems. Prior studies have revealed that sympathetic arousal increases, particularly at the beginning of the examination. Against this background it appears likely that those stress reactions during the scanning procedure may influence task performance and neural correlates. However, the question how sympathetic arousal elicited by the scanning procedure itself may act as a potential confounder of fMRI data remains unresolved today. Thirty-seven scanner naive healthy subjects performed a simple cued target detection task. Levels of salivary alpha amylase (sAA), as a biomarker for sympathetic activity, were assessed in samples obtained at several time points during the lab visit. SAA increased two times, immediately prior to scanning and at the end of the scanning procedure. Neural activation related to motor preparation and timing as well as task performance was positively correlated with the first increase. Furthermore, the first sAA increase was associated with task induced deactivation (TID) in frontal and parietal regions. However, these effects were restricted to the first part of the experiment. Consequently, this bias of scanner related sympathetic activation should be considered in future fMRI investigations. It is of particular importance for pharmacological investigations studying adrenergic agents and the comparison of groups with different stress vulnerabilities like patients and controls or adolescents and adults.
已经反复证明，功能磁共振成像（fMRI）会引发痛苦和神经内分泌反应系统。先前的研究表明，交感神经兴奋增加，特别是在检查开始时。在此背景下，扫描过程中的这些应激反应似乎可能会影响任务表现和神经相关性。然而，扫描过程本身引起的交感神经兴奋如何可能成为 fMRI 数据的潜在混杂因素，这个问题至今仍未解决。37 名未经扫描的健康受试者进行了简单的提示目标检测任务。在实验室访问期间的几个时间点获取唾液样本，评估唾液α淀粉酶（sAA）水平，作为交感活动的生物标志物。sAA 在扫描前和扫描结束时增加了两倍。与运动准备和定时以及任务表现相关的神经激活与第一次增加呈正相关。此外，第一次 sAA 增加与额区和顶区的任务诱导去激活（TID）有关。然而，这些影响仅限于实验的第一部分。因此，在未来的 fMRI 研究中，应该考虑与扫描仪相关的交感神经激活的这种偏差。对于研究肾上腺素能药物的药理学研究以及比较具有不同应激易感性的组，如患者和对照组或青少年和成年人，这一点尤为重要。
