Scarpelli Serena, D'Atri Aurora, Gorgoni Maurizio, Ferrara Michele, De Gennaro Luigi
Department of Psychology, Sapienza University of Rome , Rome, Italy.
Department of Life, Health and Environmental Sciences, University of L'Aquila , L'Aquila, Italy.
Front Psychol. 2015 May 7;6:605. doi: 10.3389/fpsyg.2015.00605. eCollection 2015.
Dreaming represents a peculiar form of cognitive activity during sleep. On the basis of the well-known relationship between sleep and memory, there has been a growing interest in the predictive role of human brain activity during sleep on dream recall. Neuroimaging studies indicate that rapid eye movement (REM) sleep is characterized by limbic activation and prefrontal cortex deactivation. This pattern could explain the presence of emotional contents in dream reports. Furthermore, the morphoanatomical measures of amygdala and hippocampus predict some features of dream contents (bizarreness, vividness, and emotional load). More relevant for a general view of dreaming mechanisms, empirical data from neuropsychological and electroencephalographic (EEG) studies support the hypothesis that there is a sort of continuity between the neurophysiological mechanisms of encoding and retrieval of episodic memories across sleep and wakefulness. A notable overlap between the electrophysiological mechanisms underlying emotional memory formation and some peculiar EEG features of REM sleep has been suggested. In particular, theta (5-8 Hz) EEG oscillations on frontal regions in the pre-awakening sleep are predictive of dream recall, which parallels the predictive relation during wakefulness between theta activity and successful retrieval of episodic memory. Although some observations support an interpretation more in terms of an intraindividual than interindividual mechanism, the existing empirical evidence still precludes from definitely disentangling if this relation is explained by state- or trait-like differences.
做梦代表了睡眠期间一种特殊形式的认知活动。基于睡眠与记忆之间的已知关系，人们对睡眠期间人类大脑活动对梦境回忆的预测作用越来越感兴趣。神经影像学研究表明，快速眼动（REM）睡眠的特征是边缘系统激活和前额叶皮质失活。这种模式可以解释梦境报告中情感内容的存在。此外，杏仁核和海马体的形态解剖学测量可以预测梦境内容的一些特征（离奇性、生动性和情感负荷）。对于做梦机制的总体观点而言，神经心理学和脑电图（EEG）研究的实证数据支持这样一种假设，即在睡眠和清醒状态下，情景记忆的编码和提取的神经生理机制之间存在某种连续性。有人提出，情绪记忆形成的电生理机制与REM睡眠的一些特殊EEG特征之间存在显著重叠。特别是，觉醒前睡眠中额叶区域的θ波（5-8赫兹）脑电振荡可预测梦境回忆，这与清醒状态下θ波活动与情景记忆成功提取之间的预测关系相似。尽管一些观察结果支持一种更多基于个体内部而非个体间机制的解释，但现有的实证证据仍然无法确定这种关系是由状态或特质样差异所解释。
