Sleep does not facilitate insight in older adults

• We tested the effect of sleep on insight problem solving in young and older adults.
• Sleep does not potentiate insight in problem solving in older adults.
• We confirm that sleep promotes insight in problem solving in young adults.
• Implicit knowledge in the task before consolidation did not enhance the gain of insight in older adults.
• Implicit knowledge before sleep potentiated the emergence of insight in young adults.

Sleep has been shown to foster the process of insight generation in young adults during problem solving activities. Aging is characterized by substantial changes in sleep architecture altering memory consolidation. Whether sleep might promote the occurrence of insight in older adults as well has not yet been tested experimentally. To address this issue, we tested healthy young and old volunteers on an insight problem solving task, involving both explicit and implicit features, before and after a night of sleep or a comparable wakefulness period. Data showed that insight emerged significantly less frequently after a night of sleep in older adults compared to young. Moreover, there was no difference in the magnitude of insight occurrence following sleep and daytime -consolidation in aged participants. We further found that acquisition of implicit knowledge in the task before sleep potentiated the gain of insight in young participants, but this effect was not observed in aged participants. Overall, present findings demonstrate that a period of sleep does not significantly promote insight in problem solving in older adults.