Four Pitfalls in Sleep and Memory Research and How to Avoid Them

Understanding the complex relationship between sleep and memory is one of the biggest challenges in neuroscience. Thousands of studies on memory consolidation suggest that sleep triggers offline memory processes, resulting in less forgetting in declarative memory and performance improvement in non-declarative memory. However, an increasing number of contradictory findings reveal potential issues with how research is conducted in this field, that weaken the reliability of these results. Here we describe four methodological pitfalls with respect to experimental designs and statistical analyses that should be avoided in order to unveil the true effect of sleep on memory consolidation: non-optimal experimental designs, task complexity, fatigue effect in repetitive tasks, and data analysis and availability. We then offer solutions that can be used in future research of sleep-dependent consolidation and also more broadly in memory research.