The last few years have seen an increasing
literature on the relationship between sleep,
memory and learning capacity (e.g. Ref.9). Recent
findings have shown that sleep plays an important
role in learning processes and memory consolidation,
10,11 although no direct relationships were
found between different kinds of memory, such as
procedural or declarative memory, and different
sleep stages, such as REM or NREM sleep.12 These
studies clearly show that sleep deprivation can
impair learning and memory for both motor
procedural (e.g. Ref.10) and declarative memory
systems (e.g. Ref.13).
It is well known that the integrity of learning and
memory processes are fundamental in school
achievement and academic performance, particularly
in individuals like children and adolescents
who are in a particular developmental phase.14–18
At this stage in life, adolescents suffer from
increasing school, family and social pressure and
from an environmentally induced delay of sleep
timing,19–21 together with changes of intrinsic
regulatory (both circadian and homeostatic) processes.
22 Taken together, these altered sleep
patterns lead to a marked increase in sleepiness23
that usually facilitates cognitive, emotional, behavioural
and academic failure.22 Surprisingly, not
much data exists regarding the specific effects of
inadequate sleep and sleepiness on daytime functioning
in children.17 Nevertheless, some experimental
evidence reinforces the common belief that
disrupted or poor sleep is usually followed by
inefficient daytime behaviour and variability in
performance. Within these activities, academic
performance and/or school achievement should
be carefully taken into consideration. As recently
pointed out in some literature reviews,24–26 learning
abilities and consequent academic performance
are particularly dependent on sleep patterns and
sleepiness levels. These impairments in neurocognitive
functioning can be observed in several kinds
of learners: from school to university students