Many studies in recent years have confirmed that sleep is conducive to learning and memory. Not only does sleep after learning has the function of memory consolidation, but sleep before learning is also necessary for subsequent learning. After long-term wakeful learning, synaptic connections in the brain increase, Enhancement saturates the synaptic gap and hinders subsequent learning. The role of sleep is to weaken the connection of synapses to the basic level, providing sufficient space and energy for subsequent learning and memory. Which of the following, if true, would best support a researcher's point of view? ['Synapses in the brain stop working during sleep.', 'Synaptic connection activities require space and energy.', 'Learning and memory must be performed in wakefulness.', 'Basal metabolic activity in the body will slow down during sleep.']