Department of Neurology, University of Lübeck, Lübeck, Germany.
PLoS One. 2010 Feb 26;5(2):e9442. doi: 10.1371/journal.pone.0009442.
Solving a task with insight has been associated with occipital and right-hemisphere activations. The present study tested the hypothesis if sleep-related alterations in functional activation states modulate the probability of insight into a hidden abstract regularity of a task.
State-dependent functional activation was measured by beta and alpha electroencephalographic (EEG) activity and spatial synchronization. Task-dependent functional activation was assessed by slow cortical potentials (SPs). EEG parameters during the performance of the Number Reduction Task (NRT) were compared between before sleep and after sleep sessions. In two different groups, the relevant sleep occurred either in the first or in the second half of the night, dominated by slow wave sleep (SWS) or by rapid eye movement (REM) sleep.
Changes in EEG parameters only occurred in the early-night group, not in the late-night group and indicated occipital and right-hemisphere functional alterations. These changes were associated with off-line consolidation of implicit task representations and with the amount of SWS but they did not predict subsequent insight. The gain of insight was, however, independently associated with changes of spectral beta and alpha measures only in those subjects from the two sleep groups who would subsequently comprehend the hidden regularity of the task. Insight-related enhancement of right frontal asymmetry after sleep did not depend on sleep stages.
It is concluded that off-line restructuring of implicit information during sleep is accompanied by alterations of functional activation states after sleep. This mechanism is promoted by SWS but not by REM sleep and may contribute to attaining insight after sleep. Original neurophysiologic evidence is provided for alterations of the functional activation brain states after sleep. These alterations are associated with a decrease in controlled processing within the visual system and with an increase in the functional connectivity of the right hemisphere, and are supported by SWS in the first half of the night.
具有洞察力地解决任务与枕叶和右脑的激活有关。本研究检验了一个假设，如果睡眠相关的功能激活状态改变会影响洞察任务隐藏抽象规则的概率。
通过β和α脑电图（EEG）活动和空间同步测量状态依赖的功能激活。通过慢皮质电位（SP）评估任务相关的功能激活。比较了在睡眠前后执行数字减少任务（NRT）期间的 EEG 参数。在两个不同的组中，相关的睡眠分别发生在夜间的前半段或后半段，主要是慢波睡眠（SWS）或快速眼动（REM）睡眠。
只有在夜间早期组中，EEG 参数才会发生变化，而夜间晚期组中不会发生，这表明枕叶和右脑功能发生了改变。这些变化与隐性任务表现的离线巩固有关，与 SWS 的量有关，但它们不能预测随后的洞察力。然而，洞察力的获得与频谱β和α指标的变化独立相关，仅在那些来自两个睡眠组的受试者中，他们随后会理解任务的隐藏规律。睡眠后右侧额叶不对称性的洞察力相关增强并不依赖于睡眠阶段。
睡眠期间隐性信息的离线重构伴随着睡眠后功能激活状态的改变。这种机制是由 SWS 促进的，而不是由 REM 睡眠促进的，可能有助于睡眠后获得洞察力。为睡眠后大脑功能激活状态的改变提供了原始的神经生理证据。这些改变与视觉系统内受控处理的减少有关，与右脑功能连接的增加有关，并得到夜间前半段 SWS 的支持。
