Pavlova Marina, Birbaumer Niels, Sokolov Alexander
Institute of Medical Psychology and Behavioral Neurobiology, MEG-Center, University of Tübingen, Gartenstrasse 29, 72074 Tübingen, Germany.
Cereb Cortex. 2006 Mar;16(3):321-7. doi: 10.1093/cercor/bhi108. Epub 2005 May 18.
Processing of biological motion represented solely by a set of lights on the joints of a human body is traditionally viewed as largely independent of attention. Here, by manipulating attention-related task demands, we assess changes in the neuromagnetic cortical response to a point-light walker. Irrespective of task demands, biological motion evokes an increase in oscillatory gamma activity over the left parieto-occipital region at 80 ms post-stimulus. Only an attended walker, however, yielded further peaks over the right parietal (120 ms) and temporal (155 ms) cortices. By contrast, the magnetoencephalographic (MEG) response to an ignored walker is restricted to the left parieto-occipital region. In addition, peaks in oscillatory activity occur in response to both attended (canonical and scrambled) configurations at 180-200 ms from stimulus onset over the right fronto-temporal regions, most likely reflecting maintenance of the target configuration in working memory. For the first time, we demonstrate that the time course and topographic dynamics of oscillatory gamma activity in response to biological movement undergoes top-down influences and can be profoundly modulated by the withdrawal of attention.
传统上认为，仅由人体关节上的一组光点所代表的生物运动的处理在很大程度上与注意力无关。在此，我们通过操纵与注意力相关的任务需求，评估了对光点行走者的神经磁皮层反应的变化。无论任务需求如何，生物运动在刺激后80毫秒会引起左顶枕区振荡伽马活动增加。然而，只有被关注的行走者在右顶叶（120毫秒）和颞叶（155毫秒）皮层产生进一步的峰值。相比之下，对被忽视的行走者的脑磁图（MEG）反应仅限于左顶枕区。此外，在刺激开始后180 - 200毫秒，振荡活动的峰值出现在右额颞区，对被关注的（标准和打乱的）构型均有反应，这很可能反映了工作记忆中目标构型的维持。我们首次证明，对生物运动的振荡伽马活动的时间进程和地形动力学受到自上而下的影响，并且可以通过注意力的撤离而受到深刻调节。
