BHS 499-07Memory and Amnesia

Memory & Development

Memory Changes

Memory is not stable or static.• Every experience we have changes our ability

to remember, distorts some info while making other info easier to remember.

People’s ongoing development affects memory.• Infancy and childhood – skills get better.

• Old age – some skills decline but others improve.

Infancy

Testing infant memory is difficult because they cannot understand or produce language.

Nonverbal behavior is studied to see how it changes as a result of some remembered experience.• The meaning of these behaviors must be

inferred, so some findings are controversial.

Four Methods

Looking method – infants stare at the novel, look away from the familiar.

Nonnutritive sucking – infants suck more slowly when bored (seeing the familiar).

Conjugate reinforcement – mobile kicking under different conditions.

Elicited imitation – recall of how to assemble a toy or do some task.

Components in Infancy

Different memory components develop at different rates based on readiness of the brain to support them.

Semantic memory – infants can create and use categories.• Ability to make some basic distinctions at 3-4

months, superordinate at 14 mo, subordinate not until 2 years.

Components in Infancy (Cont.)

Episodic memory – using conjugate reinforcement:• Infants 3 mo remember to kick after 1 week

• Rate of kicking varies with context (crib liner) Using a new mobile in between makes it

less likely they will kick to the old one. The length of time an imitated action can

be retained lengthens with age.

Components in Childhood

The brain continues to develop, so development continues into adulthood.

Semantic memory – children develop complex networks in areas of interest (dinosaurs).

Schemas & scripts appear around age 3. Categories begin to be used differently.

Components in Childhood (Cont)

Episodic memory – Older children infer implicit associations (coffee stirred with a spoon).

Older children tend to use structure more often to remember (organizing furniture by room).

Strategies for remembering emerge.

Other Childhood Changes

Working memory – rate and effectiveness of rehearsal increases.

Capacity increases because speed of processing increases (longer words retained).

Bigger knowledge base increases retention. Better able to inhibit irrelevant information –

directed forgetting increases with age up to 10 years old.

More Childhood Changes

Metamemory – steadily increases with time.• Serial position – young children do not report

recent items, but older ones do.

Young children do not understand how their memories work, but acquire knowledge.• Test taking strategies develop.

Problems with Studying Elderly

Longitudinal vs cohort studies.• Cohorts differ in level of education.

• Longitudinal studies difficult to carry out.

Health problems distort results.• Most elderly are healthy but those who are

not may have problems affecting memory.

Use it or lose it – decline in mobility parallels cognitive decline.

Changes in Old Age

Neurological changes – decline in neural conduction speed produces slowdown, especially for complex tasks.

Declines in frontal lobes – dorsolateral prefrontal lobes affected most.• This is the area where working memory and

the central executive are found.

• Decline in dopamine system.

Old Age Changes (Cont.)

Temporal lobe – older adults show global problems with learning and retrieving information.

Lateralization decreases – perhaps older adults need to recruit more cells to do the same job, decreasing specialization.

Imaging studies show that older adults use their brains differently than younger.

Theories of Decline

Speed theory – speed affects memory because some information is forgotten during the stream of thought.• Older adults process at 1.5 speed of younger.

Reduced working memory – reduced attentional capacity.• Light & Capps manipulated where a pronoun

appeared in a short story. The further from the name, the more forgetting.

More Theories of Decline

Inhibition theory – related but irrelevant info clogs the stream of thought.• Difficulty doing directed forgetting task.

• Unable to suppress info from previous tasks.

Self-initiated processing – less able to monitor their own memory processes.• Recall more affected than recognition, so

problem may be retrieval and metamemory.

Components in Old Age

Episodic memory – decline in the quantity of information remembered.• Organization of the info stays the same.

• Impact of positive info increases, negative info decreases, increase in mood congruency effects.

• More susceptible to retroactive interference, larger fan effects.

Reliance on Schemas

Due to declines in remembering, reliance on schemas is greater for older adults.• More likely to make predictions using

schemas. Episodic memory for details most likely

to be forgotten.• Semantic memory is stable or improves.

• More likely to report semantic autobiographical information, not episodic.

Source Monitoring Problems

Older adults are less effective at source monitoring.• Reliance on internal feelings instead of

memory for perceptual details leads to greater reality monitoring failures.

• Confuse perceptually similar sources (photos)

• More willing to produce false memories.

• Less likely to use environmental cues to aid recall (less able to self-initiate).

Metamemory Problems

Prospective memory – worse than younger people at both time-based and event-based tasks.• Self-initiated processing worse (take cookies

out of oven).

• Not caused by inability to make a plan.

Better in real life because alternative strategies are used.

Metamemory (Cont.)

JOLs & FOKs less accurate than for younger people.• Similar to younger people in ability to adjust

accuracy based on the info to be learned.

If a person thinks memory will be worse, it declines.• Activation of age-related stereotypes affects

performance of elderly but not young.

Strengths in Old Age

Semantic memory – little decline and knowledge accumulates.• Older adults outperform younger ones on

general knowledge tests.

• Priming effects do not change.

Real-world knowledge is an advantage.

More Strengths

Episodic memory – some aspects remain strong and even improve.• Quantity vs quality – quantitative decline but

qualitative improvement.

• Organization stays the same or improves.

Higher-level memory – mental models improve. Better at remembering content of news stories & sources.