Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA.
J Neurophysiol. 2012 Sep;108(5):1335-48. doi: 10.1152/jn.00972.2011. Epub 2012 Jun 13.
It is well established that the prefrontal cortex is involved during memory-guided tasks whereas visually guided tasks are controlled in part by a frontal-parietal network. However, the nature of the transition from visually guided to memory-guided force control is not as well established. As such, this study examines the spatiotemporal pattern of brain activity that occurs during the transition from visually guided to memory-guided force control. We measured 128-channel scalp electroencephalography (EEG) in healthy individuals while they performed a grip force task. After visual feedback was removed, the first significant change in event-related activity occurred in the left central region by 300 ms, followed by changes in prefrontal cortex by 400 ms. Low-resolution electromagnetic tomography (LORETA) was used to localize the strongest activity to the left ventral premotor cortex and ventral prefrontal cortex. A second experiment altered visual feedback gain but did not require memory. In contrast to memory-guided force control, altering visual feedback gain did not lead to early changes in the left central and midline prefrontal regions. Decreasing the spatial amplitude of visual feedback did lead to changes in the midline central region by 300 ms, followed by changes in occipital activity by 400 ms. The findings show that subjects rely on sensorimotor memory processes involving left ventral premotor cortex and ventral prefrontal cortex after the immediate transition from visually guided to memory-guided force control.
已经证实，前额皮质在记忆引导任务中起作用，而视觉引导任务则部分由额顶网络控制。然而，从视觉引导到记忆引导的力控制的转换性质尚不清楚。因此，本研究检查了在从视觉引导到记忆引导的力控制的转换过程中大脑活动的时空模式。我们在健康个体进行握力任务时测量了 128 通道头皮脑电图 (EEG)。在去除视觉反馈后，事件相关活动的第一个显著变化发生在 300 毫秒时的左中央区域，随后是 400 毫秒时的前额皮质变化。低分辨率电磁断层成像 (LORETA) 用于将最强的活动定位到左腹侧运动前皮质和腹侧前额皮质。第二个实验改变了视觉反馈增益，但不需要记忆。与记忆引导的力控制相反，改变视觉反馈增益不会导致左中央和中线前额区域的早期变化。减少视觉反馈的空间幅度会导致 300 毫秒时中线中央区域的变化，随后是 400 毫秒时枕叶活动的变化。研究结果表明，在从视觉引导到记忆引导的力控制的直接转换后，受试者依赖于涉及左腹侧运动前皮质和腹侧前额皮质的感觉运动记忆过程。
