Susac Ana, Heslenfeld Dirk J, Huonker Ralph, Supek Selma
Department of Physics, Faculty of Science, University of Zagreb, Bijenicka 32, 10 000, Zagreb, Croatia,
Brain Topogr. 2014 Sep;27(5):648-51. doi: 10.1007/s10548-013-0340-8. Epub 2013 Dec 11.
Previous studies have reported a visual analogue of the auditory mismatch negativity (MMN) response that is based on sensory memory. The neural generators and attention dependence of the visual MMN (vMMN) still remain unclear. We used magnetoencephalography (MEG) and spatio-temporal source localization to determine the generators of the sensory-memory-based vMMN response to non-attended deviants. Ten participants were asked to discriminate between odd and even digits presented at the center of the visual field while grating patterns with different spatial frequencies were presented outside the focus of attention. vMMN was calculated as the difference between MEG responses to infrequent gratings in oddball blocks and the same gratings in equiprobable blocks. The peak latency of the vMMN response was between 100 and 160 ms. The neuromagnetic sources of the vMMN localized in the occipital cortex differed from the sources evoked by the equiprobable gratings and were stimulus-dependent. Our results suggest the existence of separate neural systems for pre-attentive memory-based detection of visual change and provide new evidence that the vMMN is feature-specific.
先前的研究报告了一种基于感觉记忆的听觉失匹配负波（MMN）反应的视觉类似物。视觉MMN（vMMN）的神经发生器和注意力依赖性仍不清楚。我们使用脑磁图（MEG）和时空源定位来确定基于感觉记忆的vMMN对未被注意的偏差刺激的反应的发生器。10名参与者被要求辨别呈现于视野中心的奇数和偶数数字，同时在注意力焦点之外呈现具有不同空间频率的光栅图案。vMMN被计算为在奇数球块中对罕见光栅的MEG反应与在等概率块中对相同光栅的MEG反应之间的差异。vMMN反应的峰值潜伏期在100至160毫秒之间。vMMN的神经磁源定位于枕叶皮质，与等概率光栅诱发的源不同，且依赖于刺激。我们的结果表明存在用于基于前注意记忆的视觉变化检测的独立神经系统，并提供了新的证据表明vMMN是特征特异性的。
