Some students believe they can skip sleep ahead of exams and spend that time cramming. Since sleep loss is believed by scientists to be detrimental to memory formation, this can be an inefficient learning technique; particularly if you will need to retain that memory for future work, such as the medical boards or actual practice.

However, as will all generalizations, your mileage may vary: A new study shows that sleep loss affects memory formation differently depending on differences in the brain structure of individuals.
As written up by Science Magazine last week:

Sleep loss is bad for memory formation; however, it affects some of us more than others. Saleti et al. combined memory tests, brain imaging, and sleep EEG recordings to study the interaction between brain structure, sleep loss, and cognitive performance. Individual differences in the anatomy of the human hippocampus explained many of the differences in learning impairment after sleep loss.

These structural differences also predicted the subsequent EEG slow-wave activity during recovery sleep and the restoration of learning after sleep.

The anatomical structure of the brain may thus represent a biomarker that predicts vulnerability to sleep loss and how easily an individual will recover.

If you find you retain memories well despite getting less than your normal amount of sleep, perhaps you are the exception to the rule. However, there are many other negative aspects associated with poor sleep hygiene, such as mood disorders and weight gain.

[Illustration from Michigan Daily]