Cognitive Theories

Cognitive Theories

1. Classic Profile (Salthouse, 2004)

   • Increase in general knowledge/vocab until 60s (crystallised)
   • Linear decline in speed, reasoning and recall memory (fluid)
   • Synonym vocal, pattern comparison, raven's progressive matrices, recall memory
   • Age related effects are quite large
   • No increase in between-person variability

2. Ageing & Memory

   • Recognition vs. Recall
     • Park, Puglisi & Smith (1986): varied pictorial detail, no age difference independent of simple/complex details = recognition memory
     • Craig, Byrd & Swanson (1987): lack of environment support, 4 p groups, CR+CL, FR+CL, FR+FL, FR+FL, young did better but old as good when both CR + CL- support can eliminate ageing effects
   • Craig & McDowd (1987): self-initating encoding, recall/recognition same level of difficulty, visually presented words, cued recall: heard AD, recognition: auditory + distractors, overcompensated recall but still worse in old people, old did better in recognition
   • Explicit vs. Implicit
     • Park & Shaw (1992): stem completion task: explicit= with a word you studied, implicit: any word that comes to mind, implicit in tact = no effortful memory search

3. Reduced Working Memory Capacity (WMC) = STM + executive control

   • Stoltzfus et al., (1996): Limited capacity, individual differences, differences are a function of age
   • Complex Span task: sentences + remember letter (Daneman & Carpenter, 1980): Age affect complex more than simple (Park & Payer, 2006)
   • Poor inhibitory ability a result of decreased WMC, keeping task-relevant active, inhibiting irrelevant
   • Predicts differences in remembering disorganised scenes (Frieske & Park, 93) + reasoning performance (Salthouse, 1993)
   • Problems: WMC is broad construct, which part is limited?, no age differences (Hartley, 1986), 2nd to processing speed? (Salthouse, 1996)

4. Processing Speed Theory

   • Reduction in the speed which cognitive operations can be executed (Salthouse, 1996)
     • Problems: depends on methodology used; cross-sectional = 71% age-related processing speed + memory changes, Lemke & Zimprich (2005): 37% in longitudinal, Sliwinski & Buschke (1999): cross= 70-100, long: 6-29% but task practice in longitudinal (Salthouse, 2010)
   • Raven's matrices after controlling speed = no age differences
     • Limited time mechanism: later tasks affected by time to do earlier
     • Simultaneity mechanism: products of early tasks lost by the time gets to later task (relevant info gone)

5. Inhibitory Deficit Account

   • Impairment of processes that control the contents of WM (Stoltfuz, Hasher & Sacks, 1996)
   • Inhibition: access to WM, delete not relevant info, suppresses pre potent = stroop task
   • Poor performance in WMC tasks = poor inhibitory ability
   • Connelley, Hasher & Zacks (1991): passage of text, only italics = older adults struggle
   • Gazzallley et al. (2015): fMRI, suppress one scene/faces, BOLD signal = boosted and suppressed activity in younger people vs. passive control, older = not suppress
   • May, Hasher & Keane (1999): reading span task, big to small or small to large, low = 4/5, high lowered proactive interference - as well as young adults
   • Healey, Ngo & Hasher (2014): words followed by a cue, 1: produce a relevant word, 2: unrelated word = 2nd condition harder
   • Problems: boosting relevant the problem, different types of inhibition?, difference not independent of those on other measures (Salthouse & Meinz, 1995)

6. Sensory Functioning (sensory-cognitive function)

   • Cognitive functioning mediated by sensory functioning
   • Lindenberger & Baltes (1994): V+A acuity= 93% variance on 14 tests of cognition
   • Problems: something underlying both e.g expression of ageing brain, Lindenberger & Ghisletta (2009):moderate correlations not strong between sensory + cognitive function

7. Paradox of Cognitive Ageing

   • Not more obvious in real world?
     • Not fully aware unless pathological
     • CEOS in 60s/70s
     • Not only factor of functioning successfully
     • Lab study: memory processes isolated, pushed to the max
     • People adapt to age changes - set ways to carry out tasks when older (Salthouse, 2004)