It is well established that certain types of memory are consolidated during sleep. Now Nature News reports on findings presented at the Federation of European Neuroscience Societies Forum in Geneva last weekend, which suggest that sleep loss can lead to the formation of false memories:
Susanne Diekelmann in Jan Born‘s lab at the University of Lubeck, Germany, and her colleagues asked volunteers to learn lists of words, each list relating to a particular topic. For example, they might learn the words ‘white’, ‘dark’, ‘cat’ and ‘night’ — all of which can be linked to the word ‘black’ — but black itself would not be part of the list.
The researchers then tested their subjects’ memories after a night’s sleep or a night spent awake. They showed them the list of words again, having added a few extra words, and asked them to recall whether the words had been in the original list. The sleep-deprived group gave more false responses than the group allowed to sleep.
As is pointed out in the comments at the bottom of the article, these findings have obvious implications for the use of sleep deprivation in interrogation, at least when accurate information – as opposed to a false confession – is sought from the suspect being interrogated.
The findings also suggest that false memories are consolidated at the time of retrieval, rather than during periods of sleep deprivation; when participants who had remained awake overnight were allowed to catch up on lost sleep the following night, they produced the same number of false memories as those who had not been deprived of sleep at all.
Diekelmann and Born also found that those sleep deprived participants who were given coffee in the morning produced 10% fewer false memories than those who weren’t, and suggest that this is due to caffeine’s effects on the prefrontal cortex, one of the brain regions whose function is affected by sleep deprivation.