A deficit in the ability to form new human memories without sleep

Abstract

Evidence indicates that sleep after learning is critical for the subsequent consolidation of human memory. Whether sleep before learning is equally essential for the initial formation of new memories, however, remains an open question. We report that a single night of sleep deprivation produces a significant deficit in hippocampal activity during episodic memory encoding, resulting in worse subsequent retention. Furthermore, these hippocampal impairments instantiate a different pattern of functional connectivity in basic alertness networks of the brainstem and thalamus. We also find that unique prefrontal regions predict the success of encoding for sleep-deprived individuals relative to those who have slept normally. These results demonstrate that an absence of prior sleep substantially compromises the neural and behavioral capacity for committing new experiences to memory. It therefore appears that sleep before learning is critical in preparing the human brain for next-day memory formation-a worrying finding considering society's increasing erosion of sleep time.

Chronology and Chronicity of Altered Resting-State Functional Connectivity after Traumatic Brain Injury

“…For example, studying the effects of sleep deprivation, Yoo and colleagues found that activation in unique regions of the frontal lobe predicting memory encoding in the experimental group was accompanied by nonspecific hippocampal-subcortical hypersynchronicity. 82 These findings bear notable resemblance to observations in our longitudinal TBI sample, where attentional performance at both time points was significantly and positively associated with antiphase synchrony between the left hippocampus and right dlPFC at the subacute stage. The same relationship did not hold at the chronic time point, and in our larger analyses between chronic TBI and controls, antiphase synchrony between left hippocampus and diffuse task-positive areas in both hemispheres was decreased in TBI.…”

Sleep deprivation increases formation of false memory

“…While sleep loss can potentially perturb memory at both encoding and retrieval phases, the observation that poorer recognition can persist even after recovery sleep (Yoo et al ., 2007) suggests it is weaker encoding that increases one's susceptibility to retroactive interference.…”

“…This would provide a second opportunity to encode information that, if source‐misattributed, could inflate veridical memory score. Indeed, when declarative materials are presented only once obviating re‐learning, sleep deprivation at encoding can result in poorer memory recognition (Yoo et al ., 2007). …”

Sleep Deprivation in the Dark Period Does Not Impair Memory in OF1 Mice

“…Thus, spatial memory was impaired in rats when a 6 h SD preceded acquisition in a water maze task (Guan et al 2004), and in humans, a retention deficit was found when a night without sleep was scheduled before encoding of new episodic memories (Yoo et al 2007). In our experiment memory seemed to be more labile in those mice which learned the task at dark offset, i.e.…”

“…Thus, 6 h SD preceding acquisition of a water maze task impaired spatial memory in rats tested 24 h later, although it had not affected the learning curve during acquisition (Guan et al 2004), and a 10 h SD preceding a spontaneous alternation test impaired spatial working memory in mice (Pierard et al 2007). In human subjects a night of SD prior to learning, caused a deficit in the ability to encode new episodic memories, resulting in a worsening in retention (Yoo et al 2007). …”