Keil Julian, Adenauer Hannah, Catani Claudia, Neuner Frank
Department of Psychology, University of Konstanz and Center for Psychiatry Reichenau, Konstanz, Germany.
BMC Neurosci. 2009 Jul 17;10:83. doi: 10.1186/1471-2202-10-83.
The affective and motivational relevance of a stimulus has a distinct impact on cortical processing, particularly in sensory areas. However, the spatial and temporal dynamics of this affective modulation of brain activities remains unclear. The purpose of the present study was the development of a paradigm to investigate the affective modulation of cortical networks with a high temporal and spatial resolution. We assessed cortical activity with MEG using a visual steady-state paradigm with affective pictures. A combination of a complex demodulation procedure with a minimum norm estimation was applied to assess the temporal variation of the topography of cortical activity.
Statistical permutation analyses of the results of the complex demodulation procedure revealed increased steady-state visual evoked field amplitudes over occipital areas following presentation of affective pictures compared to neutral pictures. This differentiation shifted in the time course from occipital regions to parietal and temporal regions.
It can be shown that stimulation with affective pictures leads to an enhanced activity in occipital region as compared to neutral pictures. However, the focus of differentiation is not stable over time but shifts into temporal and parietal regions within four seconds of stimulation. Thus, it can be crucial to carefully choose regions of interests and time intervals when analyzing the affective modulation of cortical activity.
刺激的情感和动机相关性对皮层加工有显著影响,尤其是在感觉区域。然而,这种大脑活动情感调制的时空动态仍不清楚。本研究的目的是开发一种范式,以高时空分辨率研究皮层网络的情感调制。我们使用带有情感图片的视觉稳态范式,通过脑磁图(MEG)评估皮层活动。将复杂解调程序与最小范数估计相结合,用于评估皮层活动地形图的时间变化。
对复杂解调程序结果的统计置换分析显示,与中性图片相比,呈现情感图片后枕叶区域的稳态视觉诱发电场振幅增加。这种差异在时间进程上从枕叶区域转移到顶叶和颞叶区域。
可以表明,与中性图片相比,情感图片刺激会导致枕叶区域活动增强。然而,差异焦点并非随时间稳定不变,而是在刺激后四秒内转移到颞叶和顶叶区域。因此,在分析皮层活动的情感调制时,仔细选择感兴趣区域和时间间隔可能至关重要。