User:Kihis/Working memory

Aging
Working memory is among the cognitive functions most sensitive to decline in old age. Several explanations for this decline have been offered. One is the processing speed theory of cognitive aging by Tim Salthouse. Drawing on the finding that cognitive processes generally slow as people grow older, Salthouse argues that slower processing leaves more time for working memory content to decay, thus reducing effective capacity. However, the decline of working memory capacity cannot be entirely attributed to slowing because capacity declines more in old age than speed.

Another proposal is the inhibition hypothesis advanced by Lynn Hasher and Rose Zacks. This theory assumes a general deficit in old age in the ability to inhibit irrelevant information. Thus, working memory should tend to be cluttered with irrelevant content that reduces effective capacity for relevant content. The assumption of an inhibition deficit in old age has received much empirical support but, so far, it is not clear whether the decline in inhibitory ability fully explains the decline of working memory capacity.

An explanation on the neural level of the decline of working memory and other cognitive functions in old age has been proposed by West. She argues that working memory depends to a large degree on the prefrontal cortex, which deteriorates more than other brain regions as we grow old. The prefrontal cortex hemodynamics also play an important role in the impairment of working memory through a prevalence of sleeping disorders that many older adults face but it is not the only region that is influenced since other brain regions have demonstrated an output of influence within Neuroimaging studies. Within the studies of fMRI, a connection between sleep deprivation was observed through a reduction of performance on the prefrontal cortex and an overall decrease in working memory performance. Age-related decline in working memory can be briefly reversed using low intensity transcranial stimulation (TUS) to synchronize rhythms in prefrontal and temporal areas. These stimulations include noninvasive techniques that use acoustic energy to induce changes in neuronal activity.