Typ & Atyp - Week 8 - Cognitive Ageing

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Types of Memory

Short term and Working Memory - 30 seconds or less: Passive holding area for visual / verbal information

Relatively small declines in short term memory with age

Tested with strings of numbers for example, forwards

Active processing of short term information using working memory however are affected with age

Tested with saying strings of numbers backwards for example

i.e. anything where you have to process, organise, manipulate or do work on a

task….

This can have implications across a whole range of tasks: . following instructions, reading, mental

arithmetic etc.

Long Term - 30 seconds or more: also divided into Declarative memory (Episodic & Semantic) and Procedural memory (inc. Implicit memory)

Procedural memory is relatively well preserved with age, e.g. tasks such as swimming, tying a knot

However, older adults are often impaired at acquiring new motor skills - depending on the task

- See Breitenstein et al (1996) Eye tracking tasks

Implicit memory (sub heading of procedural) is without conciousness and can be measured by priming

Studies such as Light

& Singh (1987) have found that implicit memory is retained in older adults but explicit memory (conscious

recollection of previous event or experience - sub heading of declarative) is not so well retained

Declarative is memory with awareness, Procedural memory is not

Episodic - explicit memory impairments will also affect a person's ability to:

Recall specific details of a story

Recall lists of words or sentences

Remember where and when a particular event took place - SOURCE MONITORING, i.e. Did I read that in the newspaper, or did someone tell me?

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Source Monitoring & Self Generated Events

Older people less able to distinguish between different sources of self-generated events, e.g. whether they thought something or said it outloud

Anecdotal evidence for this comes from the fact that older people tend to repeat themselves / tell the same story over and over again

See - Koriat, Ben-Zur & Sheffer (1988) word repetition task: Older people remember less words in this task and repeat what they remember more

Older people also struggle to remember whether they have repeated a specific action or just imagined it

These types of problems are attributed to 'source amnesia'

Actions of Others

Older people are also less likely to remember the actions of other people accurately

See Kersten et al (2008) - old and new pairings get muddled

& Mitchell et al (2003) - re eye witness testimony

This has implications for older people being used as witnesses as not only are they more susceptible to suggestive influence after an event has occurred and inaccurate representations, inaccurate source attribution, but they are also likely to be more confident in their errors

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Free Recall vs Recognition

¨Free recall =

‘tell me all the words you can remember’

¨

¨Recognition

= ‘have you seen this word before or not?’

¨Cued recall =

e.g. Encode:

shoe – tree;

Test: shoe – ?

Age

differences are often greater for free recall tests than for recognition

They are also greater on free recall than cued recall tasks - cued recall is more spared with age

Craik (1986) – major theory

Craik stated that memory tasks differ to the extent in which they provide EXTERNAL SUPPORT (external information or cues which can guide memory at encoding or retrieval level)

For example, a recognition test provides a prompt for retrieval: "Which of these words were on the last list?"

A free recall test provides very little support, e.g. "Tell me all the words you can remember beginning with s" a person has to work harder to recall and there is a greater need for self-initiated processing

1.Self-initiated processing demands attentional resources

2.Older adults have reduced attentional resources and are less

able to carry out self-initiated processing

Craik says: “A supportive task environment that facilitates

elaborate encoding or that guides retrieval can offset the effects of reduced attentional

resources”

(See below for order of difficulty)

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Prospective Memory

- Remembering INTENTIONS

e.g. Take the bin out, post the letter, call a friend

This comes at the TOP of Craik's hierarchy....

STAGES

Encode what you need to do: "I want to post my letter"

When you need to do it, (and include retrieval cue): "I will post it on the way to the bank, when I pass the letter box by the Coop"

Retention interval - period of time between during which you do other things: phone conversation, gardening, shopping etc...

Retrieval of intention: You pass the Coop and remember you have something to do (HIGH LEVEL OF SELF INITIATED PROCESSING)

Initiate and carry out action: Post the letter in the letter box

Field Studies:

Participants go about their daily life and asked to remember something, e.g. call experimenter on a certain day

Lab Studies:

Participant occupied with an activity, e.g. word rating / general knowledge asked to make response (press button when cue word appears) when cue word arrives need to interrupt activity and perform intention without any explicit reminder

Older adult's performance depends on key distinction between: TIME BASED and EVENT BASED tasks

Time based - have to remember to check the time in the retention interval (low on external support, high on demand for self-initiated processing) - very difficult

Event based - perform a particular action when an external even occurs (cue to prompt retrieval, less need for self initiated processing) easier to do

See - Einstein

et al. (1995)

Little age difference on event based task, both groups find time based harder, but older adults especially so

Lab evidence broadly consistent with Craik’s

general theory, but not all PM tasks demand self-initiated processing , so not all not all PM tasks belong at the top of his hierarchy

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Real World Evidence

However, when it comes to real world tasks, older adults tend to perform aswell as younger people, if not better

Older people are more adjusted to have real world strategies for remembering / organisation

They are more likely to:

Remember to call experimenter on particular day

Send a postcard to experimenter on time

Log the time on a personal organiser

This could be due to routine, motivation or conscientiousness that they perform better than young people in the real world

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Semantic Memory

Long term memory for facts, world knowledge, word meaning etc...

Generally well preserved, or even enhanced in healthy ageing population

Older adults experience more 'tip of the tongue' states than younger adults (difficulty with word retrieval) with names presenting as particularly challenging

This could be due to impaired activation of phonological information

e.g. Maylor (1990) showed young and older people pictures of famous faces and gave 50 secs to name who it was

They found that people in their 50’s had TOT effect but still get the answer correct, people in their 60’s are mid way and people in their 70’s are just as likely to be in TOT as get

it correct.