Philip Ko of Vanderbilt University in the US studied the age-related
differences on how memories are stored and retrieved and sheds light on how differences
in the behavioural and neural activity of younger and older adults control the
different generation’s capability to store and recall memories. Younger
people can retrieve memories in higher definition and not that they remember
more than old people.
A team of researchers led by Ko under mentorship of Dr.
Brandon Ally studied the virtual working memory of a person, i.e. ability to momentarily
retain a limited amount of visual information in the absence of visual stimuli.
This function is reduced as a person ages naturally and to reason it, multiple
stages of encoding, maintenance, and the retrieval of memorized information was
taken into account.
A
task called “'visual change
detection” was performed by 11 older
adults of around 67 years of age and 13 younger adults of approximately 23
years of age. This task consisted of memorizing the appearance of two, three or
four coloured dots after viewing them. These dots disappeared, and then after a
few seconds the participants were presented with a single dot appearing in one
of the memorized colours or a new colour. On the basis of accuracy their
responses: either same or different, it was analyzed how well they memorize the
colours. This exactness of response is referred to as 'behavioural measure.' A
neural measure of their memory capacity was also analyzed through the Electroencephalographic
data that was collected from the participants .
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Dr. Ko
found that while behavioural measures indicated a lower capacity in older
adults than younger adults to memorize items, the neural measure of memory
capacity was very similar in both groups. This suggested that, during the upholding
stage, both groups stored the same number of items. The study is the first to
show that the behavioural and electrophysiological correlates in the working
memory capacity of older adults can be dissociated. The older adults stored the
objects at a lower resolution than younger adults, resulting in impaired
recollection. The consequence of these differences in resolution were apparent
during retrieval from visual working memory. However, younger adults were able
to use perceptual implicit memory, a different kind of visual memory, to enhance their retrieval of the stored
information.
Ko says that reason
why older adults perform poorly when their neural activity suggests their
memory capacity is intact, may be either due to poor retrieval of memories or
poor quality of storing memory, i.e. , their memory of each item might be 'fuzzier'
than that of younger adults.
