On older adults and cognitive ageing, interruptibility and distractibility

[Anderson 00]

Anderson JR. Cognitive Psychology and its Implications. 5th Edition. New York, NY, USA: Worth Publishers; 2000:531.

• changes in cognition occur throughout adulthood: cognitive ability does not uniformly increase with added years; [Salthouse 92] used WAIS-R intelligence tests (verbal intelligence: vocabulary and language comprehension - maintained throughout adulthood); dramatic decrease in performance component (reasoning and problem solving); such tests typically speeded (indicative of slower response time); this could be environmental (older adults do better at tests related to their daily work (accumulation of knowledge), while younger adults who are used to tests do better on speeded tests;
• age-related declines in brain function; brain cells gradually die and some areas are particularly susceptible; hippocampus (memory) loses 5% of its cells every decade; other cells shrink and atrophy; some evidence also for compensatory growth;
• peak of intellectual performance in one's mid-thirties [Lehman 53] studies of works of artists, scientists, philosophers;
• [Salthouse 92] claims loss of working memory w/ age; slower in information processing than younger adults, thus inhibiting ability to maintain information in working memory;

PSYC 322 notes

• theories of cognitive ageing
  • [Salthouse 96] - processing speed thoery
    • changes in PS underlie other cog. changes; we have a limited WM capacity regardless of age, ageing compromises processing efficiency (resources not smaller, longer processing time) takes longer to complete multi-step problems if earlier steps take longer, constraining later steps (simultaneity) - info from earlier steps may have decayed at later steps; exposed with timed tasks;
    • measures of PS: digit symbol coding, simple reaction time test (avg 210ms - slows with age), Ravan's progressive matrices (reasoning)
    • evidence for PS w/ longitudinal studies and negative correlation on these measures
  • [Craik 82] - working memory theory
    • self-initiated processing declines in older age, manifested in working memory
    • measures: backwards digit span, n-back test (verbal or auditory) (predicts WM, intelligence, school performance), Corsi block task (spatial task) (http://cognitivefun.net
    • is this a cohort effect? familiarity w/ computers and games?
    • responses to survey questions w/ age shows greater primacy and recency effects for MC questions;
    • relying on priming improves WM performance; additional context improves recall, complexity of sentences and sentence/picture combination improves recall (more info available) [Park 90], [Cherry 96]
  • [Hasher 88] - inhibition theory (distractibility and interruptibility)
    • ability to shield out distractions/irrelevant information w/ age (info gateway); displacement occurs - displacing what is to be remembered in STM (i.e. remembering phone number while someone shouts random #s at you)
    • go-no go test: more likely to make mistakes when distracted, must inhibit response; older adults less slow after inhibition, more likely to make errors, unable to suppress other factors, reduced impulse control; more likely to speak impulsively;
  • [Lindenberger 94] - sensory function
    • visual/auditory acuity drops > reduced processing speed, crude measure of brain integrity / cog. resource; higher education > higher cog. resource;
    • able to compensate w/ decline in resources; negative correlation w/ age: visual and auditory acuity and other declines: perceptual speed, reasoning, memory, knowledge, fluency, intelligence

• perception of time [James] - influence of memory and novel activities - good memory of activity > perception of time passing slowly, otherwise time is perceived as moving quickly;

• attention and distractibility
  • drops in divided but not necessarily sustained attention ; inhibition theory of memory relevant here; unable to suppress distractions and enhance foci; compromised attention influences PS and memory
  • enhancement and suppression [Gazzaley 05] study w/ places and faces; older adults less able to suppress, less able to enhance;
  • PFC responsible for enhancement and suppression, goal activation, attentional modulation - all change w/ age
  • [West 96] studied PFC change with age and effect on RM, PM, interference control/suppression of distractions, response inhibition (go/no-go), recall and recognition memory; evidence from patients with frontal lobe damage - neural correlates of distraction;
  • measures of distractibility: difficult to design studies to measure this; hard to design training programs for mitigating distractions;

more...

• Salthouse TA. The processing-speed theory of adult age differences in cognition. Psychological Review. 1996;103(3):403-28. Available at: http://www.ncbi.nlm.nih.gov/pubmed/8759042.

• Vance DE, Keltner NL, McGuinness T, Umlauf MG, Yuan Y. The Future of Cognitive Remediation Training in Older Adults. Journal of Neuroscience Nursing. 2010;42(5):255-264. Available at: http://content.wkhealth.com/linkback/openurl?sid=WKPTLP:landingpage&an=01376517-201010000-00004.