Sleep-learning Impairs Subsequent Awake-learning

Although we can learn new information while asleep, we cannot consciously remember the sleep-formed memories because learning occurred in an unconscious state. Here, we ask whether sleep-learning expedites the subsequent awake-learning of the same information. To answer this question, we reanalyzed data (Züst et al., 2019, Curr Biol) from napping participants, who learned new semantic associations between fake foreign-words and translation-words (guga-ship) while in slow-wave sleep. They retrieved sleep-formed associations unconsciously on an implicit memory test following awakening. Then, participants took five runs of paired-associative learning to probe carry-over effects of sleep-learning on awake-learning. Surprisingly, sleep-learning diminished awake-learning when participants learned semantic associations that were congruent to sleep-learned associations (guga-boat). Yet, learning associations that conflicted with sleep-learned associations (guga-coin) was unimpaired relative to learning new associations (resun-table; baseline). We speculate that the impeded wake-learning originated in a deficient synaptic downscaling and resulting synaptic saturation in neurons that were activated during both sleep-learning and awake-learning.

Implicit and Explicit Memory in Junior High and College Students

This study compared the performance of 25 seventh and eighth grade boys and girls on tests of implicit and explicit memory to that of 34 men and women in college. The latter performed significantly better on the explicit memory test. Young adolescents showed a significant priming effect on the implicit memory test; college students did not. Findings suggest a ceiling effect for college students. The results support the distinction between implicit and explicit memory.