Mind, Brain Imaging and Neuroethics Unit, University of Ottawa Institute of Mental Health Research (IMHR) , Ottawa, ON , Canada.
Front Hum Neurosci. 2013 Jul 29;7:437. doi: 10.3389/fnhum.2013.00437. eCollection 2013.
Previous studies suggest that there may be a distinct relationship between spontaneous neural activity and subsequent or concurrent self-specific stimulus-induced activity. This study aims to test the impact of spontaneous activity as recorded in an eyes-open (EO) resting state as opposed to eyes-closed (EC) on self-specific versus non-self-specific auditory stimulus-induced activity in fMRI. In our first experiment we used self-specific stimuli comprised of the subject's own name and non-self-specific stimuli comprised of a friend's name and an unknown name, presented during EO versus EC baselines in a 3 name condition × 2 baseline design. In Experiment 2 we directly measured spontaneous activity in the absence of stimuli during EO versus EC to confirm a modulatory effect of the two baseline conditions in the regions found to show an interaction effect in Experiment 1. Spontaneous activity during EO was significantly higher than during EC in bilateral auditory cortex and non-self-specific names yielded stronger signal changes relative to EO baseline than to EC. In contrast, there was no difference in response to self-specific names relative to EO baseline than to EC despite the difference between spontaneous activity levels. These results support an impact of spontaneous activity on stimulus-induced activity, moreover an impact that depends on the high-level stimulus characteristic of self-specificity.
先前的研究表明,自发神经活动与随后或同时的自我特定刺激诱导活动之间可能存在明显的关系。本研究旨在测试在 fMRI 中,与闭眼(EC)相比,睁眼(EO)静息状态下记录的自发活动对自我特定与非自我特定听觉刺激诱导活动的影响。在我们的第一个实验中,我们使用了自我特定的刺激,包括被试自己的名字,以及非自我特定的刺激,包括朋友的名字和一个不知名的名字,在 3 个名字条件 × 2 个基线设计中,在 EO 与 EC 基线期间呈现。在实验 2 中,我们在 EO 与 EC 期间直接测量没有刺激时的自发活动,以确认在实验 1 中发现的交互作用区域中,两种基线条件的调制效应。EO 期间的自发活动显著高于 EC,双侧听觉皮层中的自发活动显著高于 EC,而非自我特定的名字相对于 EO 基线产生更强的信号变化,而相对于 EC。相比之下,自我特定的名字相对于 EO 基线的反应与 EC 没有差异,尽管自发活动水平存在差异。这些结果支持自发活动对刺激诱导活动的影响,而且这种影响取决于自我特定性的高级刺激特征。