“Apart from dreams, researchers says learning also takes
place while people sleep.”
Unlike the long-held belief that people are dormant while
asleep, a study says they may be learning while they are sleeping instead. This
has been explained as an unconscious form of memory that is still not well
understood, according to a study by Michigan State University researchers.
The findings were published in the Journal of Experimental Psychology
on September 7.
Assistant Professor of Psychology and lead researcher,
Kimberly Fenn, Says the research is different from the conventional memory
system, “we speculate that we may be investigating a separate form of memory, distinct
from traditional memory systems. There is substantial evidence that during
sleep, your brain is processing information without your awareness and this
ability may contribute to memory in a waking state” he says.
The researchers in the study of more than 250 people suggest
that people derive vastly different effects from the “sleep memory” ability,
with some memories improving dramatically and others not at all. This ability,
they say, is a new, previously undefined form of memory.
“You and I could go to bed at the same time and get the same
amount of sleep, but while your memory may increase substantially, there may be
no change in mine.” Fenn says.
She adds that this potential separate memory ability is not
being captured by traditional intelligence and aptitude tests such as the SAT
and ACT. According to her, this is the first step to investigate whether or not
this potential new memory construct is related to outcomes such as classroom
learning.
The researchers say the study also reinforces the need for a
goodnight’s sleep, “simply improving your sleep could potentially improve your
performance in the classroom.”Fenn says.
An earlier study on sleep and its effects reported that sleep
strengthens the memory. In other words, sleep not only protects memories from
outside interferences, but it also strengthens them.
The study was presented at the American Academy of
Neurology’s 59th Annual Meeting held in Boston. It looked at memory
recall and without interference. Forty-eight people, between the ages of 18 and
30, took part in the study. According to the report, all the participants had
normal, healthy sleep routines and were not taking any medications. They were
divided evenly into four groups-a wake group with our interference, a wake
group with interference, a sleep group without interference and a sleep group
with interference. All groups were taught the same pairs of words in the
initial training session.
The study notes that the wake groups were taught the word
pairings at 9am and then tested on them at 9pm-after 12 hours of being awake.
The sleep groups were taught the word pairs at 9pm and go tested on them
(words) at 9am after a night of sleep.
Prior to testing, the interference groups were given a
second list of word pairs to remember. The first word in each pair was the same
on both lists, but the second word was different, testing the ability of the
brain to handle competing information, known as interference. The interference
groups were then tested on both lists.
The study discovers that peple who slept after learning the
information performed better by successfully recalling more words. Those in the
sleep group without interference were able to recall 12 percent more word pairings
from the first list than the wake group without interference. With
interference, the recall rate was 44 per cent higher for the sleep group.
A fellow of the American Academy of Neurology, Jeffery
Ellenbogen, who led the research, says the study was the first to show that
sleep protects memories from interference.
“These results provide important insights into how the
sleeping brain interacts with memories: it appears to strengthen them. Perhaps,
then, sleep disorders might worsen memory problems seen in dementia,” he says.
HEALTH :SLEEP: An
emotional regulator.
In another report
presented at the 23rd Annual Meeting of the Associated Professional
Sleep Societies, sleep may be important in regulating emotional responses. As
study discovered sleep selectively preserves memories that are emotionally
salient and relevant to future goals when it follows soon after learning and
the effects persist for as long as four months after the memory is created.
The study indicates that the sleeping brain seems to calculate
what is important about an experience and selects only what is adaptive for
long term storage.
According to lead author, a professor at Harvard Medical
School, Boston, Jessica Payne, it was surprising that in addition to seeing the
enhancement of negative memories over neautral scenes, there was also
selectivity withing the emotional scences with sleep only consolidating what is
most relevant, adaptive and useful about the scenes.
She also says it was more surprising that the selectivity
lasted for a full day and even months later if sleep came soon after learning,
“it may be that the chemical and physiological aspects of sleep underltying
memory consolidation are more effective if a particular memory is ‘tagged’
shortly prior to sleeping.’ Payne says.
