Department of Neurology, Columbia University New York, NY, USA.
Front Hum Neurosci. 2011 Aug 17;5:81. doi: 10.3389/fnhum.2011.00081. eCollection 2011.
Cognitive remediation involves task practice and may improve deficits in people suffering from schizophrenia, but little is known about underlying neurophysiological mechanisms. In people with schizophrenia and controls, we used magnetoencephalography (MEG) to examine accuracy and practice-related changes in parameters indexing neural network structure and activity, to determine whether these might be useful assays of the efficacy of cognitive remediation. Two MEG recordings were acquired during performance of a tone discrimination task used to improve the acuity of auditory processing, before and after ∼2.5 h of task practice. Accuracy before practice was negatively correlated with beta-band cost efficiency, a graph theoretical measure of network organization. Synthetic aperture magnetometry was used to localize brain oscillations with high spatial accuracy; results demonstrated sound and sensorimotor modulations of the beta band in temporo-parietal regions and the sensorimotor cortex respectively. High-gamma activity also correlated with sensorimotor processing during the task, with activation of auditory regions following sound stimulation, and activation of the left sensorimotor cortex preceding the button press. High-gamma power in the left frontal cortex was also found to correlate with accuracy. Following practice, sound-induced broad-band power in the left angular gyri increased. Accuracy improved and was found to correlate with increased mutual information (MI) between sensors in temporal-parietal regions in the beta band but not global cost efficiency. Based on these results, we conclude that hours of task practice can induce meso-scale changes such as increased power in relevant brain regions as well as changes in MI that correlate with improved accuracy.
认知矫正包括任务练习，可能会改善精神分裂症患者的缺陷，但对其潜在的神经生理机制知之甚少。我们使用脑磁图（MEG）检查了索引神经网络结构和活动的参数在准确性和与练习相关的变化，以确定这些是否可以作为认知矫正效果的有用指标，在精神分裂症患者和对照组中进行了研究。在执行用于提高听觉处理敏锐度的音调辨别任务期间，进行了两次 MEG 记录，分别在约 2.5 小时的任务练习之前和之后进行。练习前的准确性与β频段成本效率呈负相关，β频段成本效率是一种网络组织的图论度量。合成孔径磁强计用于以高空间精度定位脑振荡；结果表明，β频段在颞顶区域和感觉运动皮层中存在声音和感觉运动调制。高γ活动也与任务期间的感觉运动处理相关，听觉区域在声音刺激后激活，左感觉运动皮层在按钮按下之前激活。还发现左额前皮质的高γ活动与准确性相关。练习后，左角回的声诱导宽带功率增加。准确性提高，并且发现与颞顶区域β波段中传感器之间的互信息（MI）增加相关，而与全局成本效率无关。基于这些结果，我们得出结论，数小时的任务练习可以引起与练习相关的大脑区域中功率增加以及与准确性提高相关的 MI 变化等中尺度变化。
