Editing Working memory (section)

=== Aging ===
{{Original research section|reason=Refer to [[Talk:Working memory#Aging: pure original research]] to learn more.|date=April 2021}}
Working memory is among the cognitive functions most sensitive to decline in [[old age]].<ref name="Hertzog 2003">{{cite journal | vauthors = Hertzog C, Dixon RA, Hultsch DF, MacDonald SW | title = Latent change models of adult cognition: are changes in processing speed and working memory associated with changes in episodic memory? | journal = Psychology and Aging | volume = 18 | issue = 4 | pages = 755–769 | date = December 2003 | pmid = 14692862 | doi = 10.1037/0882-7974.18.4.755 }}</ref><ref name="Park, D. C. 2002">{{cite journal | vauthors = Park DC, Lautenschlager G, Hedden T, Davidson NS, Smith AD, Smith PK | title = Models of visuospatial and verbal memory across the adult life span | journal = Psychology and Aging | volume = 17 | issue = 2 | pages = 299–320 | date = June 2002 | pmid = 12061414 | doi = 10.1037/0882-7974.17.2.299 }}</ref> Several explanations for this decline have been offered. One is the processing speed theory of cognitive aging by Tim Salthouse.<ref>{{cite journal | vauthors = Salthouse TA | title = The processing-speed theory of adult age differences in cognition | journal = Psychological Review | volume = 103 | issue = 3 | pages = 403–428 | date = July 1996 | pmid = 8759042 | doi = 10.1037/0033-295X.103.3.403 }}</ref> 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.<ref name="Park, D. C. 2002" /><ref>{{cite journal | vauthors = Mayr U, Kliegl R, Krampe RT | title = Sequential and coordinative processing dynamics in figural transformations across the life span | journal = Cognition | volume = 59 | issue = 1 | pages = 61–90 | date = April 1996 | pmid = 8857471 | doi = 10.1016/0010-0277(95)00689-3 | s2cid = 25917331 }}</ref> Another proposal is the inhibition hypothesis advanced by [[Lynn Hasher]] and Rose Zacks.<ref>{{cite book | vauthors = Hasher L, Zacks RT | date = 1988 | chapter = Working memory, comprehension, and aging: A review and new view. | veditors = Bower GH | title = The psychology of learning and motivation | volume = 22 | pages = 193–225 | location = New York | publisher = Academic Press | isbn = 978-0-08-086373-3 | oclc = 476167241 }}</ref> 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<ref>{{cite book | vauthors = Hasher L, Zacks RT, May CP | date = 1999 | chapter = Inhibitory control, circadian arousal, and age. | veditors = Gopher D, Koriat A | title = Attention and Performance | pages = 653–675 | location = Cambridge, MA | publisher = MIT Press | isbn = 978-0-262-31576-0 | oclc = 1120891520 }}</ref> 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.<ref>{{cite journal | vauthors = West RL | title = An application of prefrontal cortex function theory to cognitive aging | journal = Psychological Bulletin | volume = 120 | issue = 2 | pages = 272–292 | date = September 1996 | pmid = 8831298 | doi = 10.1037/0033-2909.120.2.272 }}</ref> 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.<ref>{{cite journal | vauthors = Gao J, Zhang L, Zhu J, Guo Z, Lin M, Bai L, Zheng P, Liu W, Huang J, Liu Z | display-authors = 6 | title = Prefrontal Cortex Hemodynamics and Functional Connectivity Changes during Performance Working Memory Tasks in Older Adults with Sleep Disorders | journal = Brain Sciences | volume = 13 | issue = 3 | pages = 497 | date = March 2023 | pmid = 36979307 | pmc = 10046575 | doi = 10.3390/brainsci13030497 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Wu G, Wang Y, Mwansisya TE, Pu W, Zhang H, Liu C, Yang Q, Chen EY, Xue Z, Liu Z, Shan B | display-authors = 6 | title = Effective connectivity of the posterior cingulate and medial prefrontal cortices relates to working memory impairment in schizophrenic and bipolar patients | journal = Schizophrenia Research | volume = 158 | issue = 1–3 | pages = 85–90 | date = September 2014 | pmid = 25043264 | doi = 10.1016/j.schres.2014.06.033 | s2cid = 36643966 }}</ref> Within the studies of fMRI, a connection between sleep deprivation was observed through a reduction of performance on the prefrontal cortex and a overall decrease in working memory performance.<ref>{{cite journal | vauthors = Guo Z, Jiang Z, Jiang B, McClure MA, Mu Q | title = High-Frequency Repetitive Transcranial Magnetic Stimulation Could Improve Impaired Working Memory Induced by Sleep Deprivation | journal = Neural Plasticity | volume = 2019 | pages = 7030286 | date = 2019-12-12 | pmid = 31915432 | pmc = 6930796 | doi = 10.1155/2019/7030286 | doi-access = free }}</ref> Age-related decline in working memory can be briefly reversed using low intensity transcranial stimulation to synchronize rhythms in prefrontal and temporal areas.<ref>{{Cite news |url= https://www.theguardian.com/science/2019/apr/08/scientists-use-electrical-pulses-reverse-memory-decline-ageing|title=Scientists reverse memory decline using electrical pulses| vauthors = Devlin H |date=2019-04-08|work=The Guardian|access-date=2019-04-09|language=en-GB|issn=0261-3077}}</ref>

The neurobiological bases for reduced working memory abilities has been studied in aging macaques, who naturally develop impairments in working memory and the executive functions.<ref>{{cite journal |last1=Morrison |first1=John H. |last2=Baxter |first2=Mark G. |title=The ageing cortical synapse: hallmarks and implications for cognitive decline |journal=Nature Reviews Neuroscience |date=April 2012 |volume=13 |issue=4 |pages=240–250 |doi=10.1038/nrn3200 |pmid=22395804 |pmc=3592200 }}</ref> Research has shown that aged macaques have reduced working memory-related neuronal firing in the dorsolateral prefrontal cortex, that arises in part from excessive cAMP-PKA-calcium signaling, which opens nearby potassium channels that weaken the glutamate synapses on spines needed to maintain persistent firing across the delay period when there is no sensory stimulation.<ref>{{cite journal |last1=Wang |first1=Min |last2=Gamo |first2=Nao J. |last3=Yang |first3=Yang |last4=Jin |first4=Lu E. |last5=Wang |first5=Xiao-Jing |last6=Laubach |first6=Mark |last7=Mazer |first7=James A. |last8=Lee |first8=Daeyeol |last9=Arnsten |first9=Amy F. T. |title=Neuronal basis of age-related working memory decline |journal=Nature |date=August 2011 |volume=476 |issue=7359 |pages=210–213 |doi=10.1038/nature10243 |pmid=21796118 |pmc=3193794 |bibcode=2011Natur.476..210W }}</ref> Dysregulation of this process with age likely involves increased inflammation with age.<ref>{{cite journal |last1=Arnsten |first1=Amy F. T. |last2=Datta |first2=Dibyadeep |last3=Wang |first3=Min |title=The genie in the bottle-magnified calcium signaling in dorsolateral prefrontal cortex |journal=Molecular Psychiatry |date=August 2021 |volume=26 |issue=8 |pages=3684–3700 |doi=10.1038/s41380-020-00973-3 |pmid=33319854 |pmc=8203737 }}</ref> Sustained weakness leads to loss of dendritic spines, the site of essential glutamate connections.<ref>{{cite journal |last1=Morrison |first1=John H. |last2=Baxter |first2=Mark G. |title=The ageing cortical synapse: hallmarks and implications for cognitive decline |journal=Nature Reviews Neuroscience |date=April 2012 |volume=13 |issue=4 |pages=240–250 |doi=10.1038/nrn3200 |pmid=22395804 |pmc=3592200 }}</ref>