蔡安庭
Although the negative effects of sleep deprivation on learning, memory and executive function are well-known, an increasing number of studies have put forward that these impairments are mainly due to a disturbance in sleep-dependent memory consolidation rather than fatigue alone. This paper investigates the connection between sleep and memory and cognition, examines how the brain processes information during sleep to promote learning, and enhances high-order thinking skills. Currently, it has been shown that memories formed in a waking state are organised during sleep through cooperation among the hippocampus, neocortex and prefrontal cortex. Meanwhile, there is temporal coupling between the cortical slow oscillations, thalamocortical sleep spindles and hippocampal sharp-wave ripples which collectively promote hippocampal replay and cortical plasticity and drive a redistribution of newly acquired information through long-term cortical networks. Synaptic homeostasis which keeps the brain efficient and prevents the loss of learning capability also mentioned in this review. All the above mechanisms are disrupted when sleep is lost, there is an impact on the communication between the hippocampus and cortex and memory and executive function are reduced. Finally, behaviour and neuroscience-based interventions to enhance sleep-dependent memory consolidation and thus improve cognitive functioning are discussed. Overall, the available evidence suggests that sleep primarily affects cognition via modulation of memory processes, and better understanding of the physiology of sleep can help improve cognitive function and contribute to new therapeutic approaches.