Selective benefits of caffeine after sleep deprivation

Sleep deprivation negatively affects our thinking, but it is not clear which cognitive processes are directly impacted. This study tested whether the cognitive performance issues caused by sleep deprivation derive from deficits in focused attention, and how caffeine might help overcome these deficits. Sleep-deprived participants performed two tests – a reaction time test that relied on sustained attention, and a “placekeeping” test that did not heavily rely on sustained attention.

As expected, sleep deprivation impaired performance on both tests. Caffeine, which is known to enhance attention after sleep deprivation, improved performance on the reaction time test but not the placekeeping test. The authors conclude that sleep deprivation negatively affects a range of cognitive processes, not limited to attention, but that caffeine selectively benefits attention-related cognitive processes.

Stepan et al. (2021) Caffeine selectively mitigates cognitive deficits caused by sleep deprivation. Journal of Experimental Psychology: Learning, Memory and Cognition 47(9): 1371-1382 DOI: http://dx.doi.org/10.1037/xlm0001023

The hippocampus creates a narrative structure for memory

The hippocampus is known to use location and time to anchor and link memories. In this study, researchers show that the human hippocampus also gives memories a narrative structure, integrating linked events to help memory recall.

Using fMRI, the authors found that two events linked into a coherent narrative produced more similar activity patterns in the hippocampus during memory encoding, as compared to events in a non-coherent narrative. At recall, activity in the hippocampus was more similar to encoding activity for coherent versus non-coherent narratives, and this similarity helped recall.

Cohn-Sheehy et al. (2021) The hippocampus constructs narrative memories across distant events. Current Biology DOI: https://doi.org/101016/jcub.2021.09.013

Good habits to help learning and mental well-being

In this short review, the authors analyzed research published in the past 20 years regarding how ‘good habits’ might promote learning and well-being. These habits included healthy eating, exercise, rest and sleep, optimism, stress management, social interaction, variety and challenge, and looking to learn new things. The authors suggest each of these can help brain health or learning via effects on cognitive processes like attention, memory, cognitive flexibility, and problem solving. Importantly, each of these good habits can be readily targeted by students for self-improvement, potentially protecting against adolescent anxiety and depression.

Ekman et al. (2021) A flourishing brain in the 21^st century: a scoping review of the impact of developing good habits for mind, brain, well-being, and learning. Mind, Brain, and Education DOI: https://doi.org/10.1111/mbe.12305

Putting a positive spin on negative memories

Recalling negative memories – things we’d rather forget – can take an emotional toll. If we then stew on these memories, we make ourselves more prone to mental health concerns including anxiety and depression. In this study, researchers show that by intentionally focusing on positive aspects of a negative memory, a person can update the memory’s contents. When the memory is recalled at a later date, the emotional associations are then less negative. This reframing of a negative memory lasted at least 2 months (the longest time-point tested), and evidence for it could be seen in changes to brain activity.

Speer et al. (2021) Finding positive meaning in memories of negative events adaptively updates memory. Nature Communications 12: 6601 DOI: https://doi.org/10.1038/s41467-021-26906-4