Samuel R. Rosenthal¹ (), Emma Megla¹, Wilma A. Bainbridge^1,2; ¹Department of Psychology, University of Chicago, Chicago, IL USA, ²Neuroscience Institute, University of Chicago, Chicago, IL USA

It is widely accepted that the activities performed between encoding and recall impact the quality of memory, with sleep better preserving memory (Ellenbogen et al., 2006). However, recent studies have challenged this idea, finding a lack of evidence for a sleep effect (Talamini et al., 2022). Additionally, measuring memory content through drawing has been shown to characterize memories beyond other behavioral methods (Bainbridge et al., 2021). In line with classical work, we hypothesized that sleeping for the duration of a delay period would result in greater recall accuracy in drawings than remaining awake. To test this, we recruited participants (N=190) on Prolific to encode four scene images before drawing them from memory after a 10- hour delay, with participants either awake or asleep over this interval. Additionally, to obtain a baseline of memory without a delay, each participant drew four additional images from memory immediately after seeing them. All drawings were then scored online by separate participants to determine the specific image recalled (N=311) and the number of objects in each drawing (N = 393). We found that participants recalled significantly fewer images after a delay than immediately after encoding, and that recalled images contained fewer objects. However, we found that actions taken between encoding and recall had no significant effect on the quality of memory, with no difference in the number of images remembered or their level of detail between sleep and wake conditions. We found Bayesian evidence for the null hypothesis, suggesting that a lack of difference between sleep and wake was not due to a lack of evidence, but instead a null effect. These results introduce new questions about the commonly accepted belief that sleep benefits memory and suggests that sleep may have minimal impact on the details we recall from a memory.