Chapter 13nalvarado/PSY335 PPTs/Baddeley... · 2015. 7. 21. · Memory as We Age An irony –comparing our own current memory with our past memory requires memory. People are less

+

Chapter 13

Memory and Aging

+Memory as We Age

An irony – comparing our own current memory with our past

memory requires memory.

People are less able to accurately report memory lapses as

they age.

Sunderland et al. (1986)

Complaints about memory in the elderly are more related to

depression than actual memory performance.

Rabbit and Abson (1990)

Impaired memory is the earliest and best predictor of the onset

of Alzheimer’s disease.

2

+Methods for Studying Aging

A representative sample of people tested

repeatedly over time

Advantages:

The effect of age can be determined on

an individual basis, helping to pinpoint

precursors of disease

Disadvantages:

Expensive

Time consuming

High dropout rate, often making the

sample less representative

Practice Effects:

Participants get better at taking the

same test with repeated testings

Different groups of people are sampled across

the age range, with each being tested once

Advantages:

No re-testing

Quicker and less expensive

Lower dropout rate

Disadvantages

Performance can’t be related to

earlier/future data

Cohort Effect:

People born at different times

differ due to:

Diet

Education

Number of siblings

Social factors (war,

economic depression)

Longitudinal Studies Cross-Sectional Studies

0 yrs +10 yrs +20 yrs

Test #1 Test #2 Test #3

20-year-

olds

0 yrs

20-year-

olds

30-year-

olds

Test #1

40-year-

olds

3

+Cohort Effects

Flynn Effect:

IQ has been rising across

generations (Raven’s matrices)

People have become taller and

more educated, while family

size has shrunk across

generations

From Rönnlund and Nilsson (2008). Copyright © Elsevier.

Reproduced with permission.

From Rönnlund and Nilsson (2008). Copyright © Elsevier.

Reproduced with permission.

4

+Methods for Studying Aging

Cross-sectional and longitudinal studies lead to different results

Cohort and practice effects can be quite influential

A Comparison

Memory Decline with Age

Longitudinal

Data

Cross-Sectional

Data

Based on Rönnlund et al. (2005).

5

+A Hybrid Method

Combine longitudinal and cross-sectional approaches

Add a new cohort at each test point

Comparison down the columns measures learning effects

e.g. 30-year-old cohort Test #1 to 20-year-old cohort Test #2

So both are then 30 years old at that point

Comparisons across a test point for each group measure cohort effects

e.g. 20-year-old cohort Test #1 to 30-year-old cohort’s Test #1

0 yrs +10 yrs +20 yrs

Test #2 Test #3

20-year-

olds

30-year-

olds

40-year-

olds

6

+Working Memory (WM) and Aging

Type of Memory Example Test General Findings

Verbal span Digit span Declines by < 1 item

Visual span Corsi block tapping Declines by < ½ an item

Verbal working

memory

Recalling words in

alphabetical order

Modest decline

Sentence span Small decline

WM span progressively declines with age

But it is a very small decline

Effects are larger when tasks involve speed of processing or episodic, long-term memory

May et al. (1999)

The WM decline may be due to a build up of proactive interference that older adults are less able to inhibit

7

+Working Memory and Aging

Hasher and Zacks’ (1988) Inhibition Deficit Hypothesis of Aging: A major cognitive effect of aging is the reduced capacity to inhibit irrelevant stimuli

Molander and Bäckman (1989):

Participants:

Older and younger mini-golf players, matched in skill

Task:

Make golf shots

Results:

Concentration (measured by heart-rate deceleration) increased in the younger under competition conditions and performance was maintained, in contrast to a decline in performance in the elderly. However, there were large individual differences.

In another study, Bäckman and Molander (1986) showed that competition decreased the accurate recall of specific shots, and increased irrelevant recall in the older golfers, but did not influence recall in the young.

Conclusion:

Older adults are less able to shut out potential distracters.

Inhibiting Interference

8

+Working Memory and Aging

Charness (1985):

Younger chess players scan

more possible moves.

Older chess players scan

fewer moves but in greater

depth.

May reflect increased

difficulty keeping track of

multiple sources of

information.

Divided Attention in Aging:

Dual-task performance is

worse in advanced age than

on the two separate tasks.

This probably reflects

general difficulty handling

heavy cognitive loads,

however.

When tasks are made

easier, dual-task

performance is not

affected by age.

Concentration and Attention

9

+Aging and Long-Term Memory

Episodic memory declines steadily through the adult years, across

the board:

Recall and recollection tests

Verbal and visual materials

Rivermead Behavioural Memory Test (everyday memory situations)

Doors and People Test (people’s names, locations)

Memory for card hands

Memorizing passages

Memory for conversations

The magnitude of the decline depends on the nature of the task and

the method of testing (recall vs recognition).

Episodic Memory

10

+Declines in Episodic Memory

The overall decline in episodic memory is modulated by:

Processing capacity of the learner

Elderly take longer to perceive and process materials

Elderly are less likely to develop and use complex learning

strategies

Level of environmental support provided during retrieval

Age effects are largest in tests lacking external cues (e.g. free

recall)

Modulating Factors (Craik, 2005)

11


Naveh-Benjamin (2000)

Task:

A recognition test for word pairs that were either semantically related or not

Results:

The older group had difficulty for unrelated items, but not for related

Initial Conclusion:

Elderly are less able to form new associative links

Follow-up (Naveh-Benjamin et al., 2003):

Gave younger group a concurrent task, which resulted in impairment for both related and unrelated items—this didn’t match the elderly group’s results – so it isn’t that the elderly are just slower processing information.

Final Conclusion:

Associative Deficit Hypothesis: The differences between young and old are attributable to basic learning capacity, rather than to attentional or strategic differences related to processing speed.

Limited Attention or Capacity?

12


An age-related difficulty in binding together unrelated things

Simply recognizing old faces or names is unaffected by age

However, a concurrent task does reduce performance

Recalling which name went with a face, is diminished in the elderly, as this requires binding

This decline is even more pronounced than in the divided-attention condition

Self-Performed Task Effect:

Age effects are minimized by asking elderly to perform an action associated with a to-be-remembered item

This deepens encoding, providing auditory, visual, manual, and self-related codes for the memory

Associative Deficit Hypothesis

From Naveh-Benjamin et al. (2004b). Copyright © American

Psychological Association. Reprinted with permission.

13

―Break the match-stick.

Shake the pen‖


Age effects are clearest in recall tests, which lack external

cues, while recognition tends to be relatively preserved in the

elderly.

This difference may reflect a combination of:

Fewer retrieval cues in the recall task

A greater involvement of association in free recall

Whether recognition is impaired or not depends on the nature of

the task:

If familiarity (―knowing‖) is sufficient—no deficit

If recollection (―remembering‖) is necessary—some impairment

Level of Environmental Support at Retrieval

14


Recollection based

Involves remembering the

event in its context

Declines substantially with age

Does not represent a

difference in confidence

between young and old

Consistent with the

associative deficit hypothesis

of aging

Familiarity based

Able to recognize an item as

familiar, without being able to

recall the context

Relatively spared in the elderly

Remembering Knowing

Recognition: Remembering and Knowing

15


Prospective Memory:

Remembering to carry out an intended action in the future without explicit reminders

Test:

Participants perform an ongoing task and respond either

After a specified time

After a cue occurs

Results:

An age-related decrement for both time-based and event-based tasks

Prospective memory requires:

Encoding the action to be performed

Encoding the time when it should be

performed

Maintaining the information over a

delay

More difficult in real-life situations

with divided attention

Through rehearsal and/or periodic

retrieval from LTM

An external retrieval cue helps

Actually performing the task when

appropriate

Prospective Memory in the Laboratory

16


Unlike laboratory situations, in real-life prospective memory scenarios the elderly often perform better than younger adults.

Example Tasks:

Ask participants to make a telephone call or send a postcard at a specified time.

Rationale:

Older people are more aware of their memory limitations and compensate with various strategies, such as:

Diaries

Reminders

Older people live more ordered and structured lives, making it easier to form plans.

Older people may have been more motivated to perform well on a memory task; younger people can explain memory slips by ―being too busy‖.

Prospective Memory in Real Life

17

+Semantic Memory and Aging

Semantic memory does not decline with age

It actually expands with age in some areas:

Vocabulary

Historical facts

Speed of access (a more sensitive measure) does decline, however.

Naturalistic, longitudinal diary study (Kemper, 1990) revealed:

Older adults tend to use sentences that demand less working memory.

But they also write ―better‖ and ―more interesting‖ sentences.

Baddeley et al.’s (1992) Speed and Capacity of Language Processing (SCOLP) Test:

Spot-the-word vocabulary test:

Participants pick the real word from the pseudo-word

Highly resistant to age and disease

Semantic processing test:

Participants verify sentences as quickly as possible

High accuracy rates

Reaction times are very sensitive to age and other factors

18

+Implicit Learning and Memory

Results are mixed, due to the

wide range of implicit processes

Moderately impaired with

advanced age:

Priming tasks involving

response production (e.g.

stem completion)

Small/no impairment in the

elderly:

Identification tasks (e.g.

lexical decision/word

fragment)

Stronger implicit effects in the elderly

False Fame Effect:

Participants first see unfamiliar names

Then are asked to mark names that are famous

Previously processed, unfamiliar names are judged as more famous

Especially true for elderly participants

Due to impaired recollection, forcing them to rely on familiarity

The elderly may be more susceptible to false information and leading questions

19


Motor performance declines with age

Speed of perception and movement decline

Leads to slower learning rate on time-based tasks

The rate of motor learning need not decline with age, however

Young and old adults show comparable rates when learning:

A sequence of motor movements

New stimulus–response mappings

To make serial responses to a number of stimuli under self-paced

conditions

To navigate a computer maze

Motor Skills

20


Generally:

When the response is

obvious and performance is

measured in terms of speed

improvements

The elderly perform well

When the response is non-

obvious, novel associations

must be learned

Older adults are impaired

This is often the case for

learning about new

technologies

Wilson, Cockburn, and

Baddeley (1989)

Task:

Patients learn a simple

process of entering the

time/date into a handheld

computer

Results:

Rate of learning was

extremely sensitive to

episodic memory deficits

21

+Resisting Age Effects

Factors tending to correlate with resistance to memory impairment:

Good physical health

Appropriate diet

Regular exercise

Continued mental activity

But rates of decline don’t differ across professors/blue-collar workers (Christensen et al., 1997)

Meaningful material may allow the active learner to compensate for declining episodic memory (Shimamura et al., 1995)

Explicit memory training (e.g. mnemonics) can help

But young participants gain substantially more from training than the elderly

An enriched environment (at least it works for rats …)

Better to be safe than sorry:

Follow the tips, even though evidence is still lacking in some respects

22

+Resisting Age Effects

Ball et al. (2002)

Participants:

2,832 older adults, divided into four groups

6-week Training Program:

Group 1: Strategy training; practice on words and shopping lists

Group 2: Practice on verbal reasoning tasks

Group 3: Speed training on visual search and divided attention tasks

Group 4: Controls (no training)

Final testing all the task types and on everyday tasks

Results:

Groups 1 to 3 improved on the skills trained

Despite being tested on novel materials

No change occurred for untrained skills, however

Improvements did not generalize to everyday tasks either

Conclusion:

Only specific skills can be trained; no generalization

It’s possible that training had some protective effects

Memory Training Programs—Worth It?

23

+Theories of Aging

Many of the cognitive effects of

aging are caused by reduced

processing speed

Based on extensive

correlational data

Digit Symbol

Substitution Test (DSST)

is a good predictor of age

deficits

The rest of the decline could

be caused by a more general

decline in cognitive

functioning (Salthouse &

Becker, 1998)

Problems with the theory:

Measures that correlate with age

deficits aren’t pure speed tests

DSST also involves strategy and

working memory

Many other physical and cognitive

capacities that decline with age

could have a causal effect

Speed measures don’t always

explain the most variance

Grip strength is an even better

predictor!

Baltes and Lindenberger

(1997)

Speed Theory -- Salthouse (1996)

24

+Theories of Aging

Reduced processing resources

Dividing young participants’ attention can mimic performance of older adults

However, this isn’t always true

e.g. Naveh-Benjamin et al. (2003; 2004)

Episodic deficits are more like amnesia than an attentional limitation

Conclusion:

Probably one of many factors

Reduced ability to inhibit

irrelevant information (Hasher,

Zacks, & May, 1999)

Problems:

Why would this influence

free recall?

Why is performance on the

Peterson task not

influenced by age?

After all, forgetting on

this task is assumed to

be caused by built up

proactive interference

Reduced WM Capacity – Inhibition Theory

25

+Theories of Aging

The frontal lobes atrophy with advanced age

Tasks thought to be supported by the frontal lobe also tend to

decline with age

These tasks typically rely on the executive component of working

memory and/or inhibition

However, the correlation between frontal lobe atrophy and age-

related cognitive decline is weak and the theory is not well-specified

currently

Frontal Lobe Deficits

26

+The Shrinking Brain

Region As we age, this region …

Overall brain Shrinks

Ventricles Expands

Frontal lobes Shrinks most rapidly

Temporal lobes Shrinks slowly

Hippocampus

Shrinks slowly, then accelerates

(possibly due to disease)

Loses 20–30% of its neurons by

age 80

Occipital lobes Shrinks slowly

The latency of Evoked Response Potentials (ERP) increases with age

The P300 increases at an average of 2 ms/year

The rate of slowing becomes more dramatic in dementia

27

+The Aging Brain

Broader activations in the elderly:

WM and visual attention yield bilateral activation in the elderly (Cabeza et al., 2004)

It is strongly lateralized in young participants

Autobiographical memory activation in the hippocampus is bilateral in the elderly (Maguire & Frith, 2003)

It is left lateralized in young participants

Use of other brain structures is thought to compensate for overload of one brain component

Reduced activations in the elderly:

Elderly don’t show occipito-temporal activation that younger participants do in a complex visual memory task (Iidaka et al., 2001)

Suggests the elderly aren’t using visual imagery

Elderly benefited less from a visual mnemonic strategy

With complex tasks, the elderly are no longer able to compensate and so rely on simpler strategies

Neuroimaging Studies

28

+The Aging Brain

Dopamine

Related to numerous cognitive functions

Agonists (e.g. bromocriptine) improve spatial working memory

Antagonists (e.g. haloperidol) diminishes spatial working memory

Levels correlate with episodic memory performance (Bäckman et al., 2000)

R2 = 38% on word recognition

R2 = 48% on face recognition

Decreases 5–10% per decade of life

According to both post-mortem and PET studies

Depletion is associated with cognitive deficits in Parkinson’s and Huntington’s diseases

Covarying out dopamine level nearly eliminates the effect of age on memory performance (Erixon-Lindroth et al., 2005)

Neurotransmitters

29

+Normal Changes with Aging

Normal changes with age:

Slower thinking.

Difficulty paying attention.

Need more cues - like words,

pictures, smell, etc. - to recall

information.

Using fewer memorization

skills like visualization and

organization.

Associations are more

difficult.

Decline in vision and hearing.

Common causes:

Health related:

High blood pressure

Prescription drugs

Bad nutrition

Low Blood Sugar or diabetes

Depression

Anxiety

Taking multiple prescriptions

Lifestyle – lack of sleep, lack of activity, stress

http://www.alz.org/alzheimers_disease_10_signs_of_alzheimers.asp



+Alzheimer’s Disease (AD)

Prevalence:

Accounts for over 50% of senile dementia cases

Occurs to 10% of the population over age 65

The rate of occurrence increases with age

Diagnosis:

Requires memory impairment plus two other deficits

Language, action control, perception, or executive function

Difficult to diagnose early

Ultimate diagnosis typically requires post-mortem examination finding dense

Amyloid plaques

Neurofibrillary tangles

Warning signs (Petersen et al., 2001):

Memory loss affecting job skills

Difficulty performing familiar tasks

Language problems

Disorientation in time and place

Poor/decreased judgment

Problems with abstract thinking

Misplacing things

Changes in mood/behavior

Changes in personality

Loss of initiative

Primary feature:

Defective episodic memory

31


Medial Temporal Lobes & Hippocampus

• Initial memory problems

Temporal & Parietal Lobes

Other Brain Regions

Disease Progression

32


Garrard et al. (2005) studied the progression of AD in

Murdoch’s writings.

Linguistic problems increased as the disease progressed

Difficultly coming up with specific words

Spelling deteriorated

Sentences became shorter and used fewer

low-frequency words

This was probably a compensatory strategy

Semantic difficulties

Major problems in defining words appropriately

Naming pictures became difficult

Difficulty generating items from a semantic category

A Case Study: Novelist and Philosopher Iris Murdoch

33

http://en.wikipedia.org/wiki/File:Iris_poster.jpg


Deficits in/for:

Recall

Recognition

Verbal materials

Visual materials

Everyday memory

Recency is relatively preserved (like amnesic syndrome)

At late stages, recency also tends to decline

Performance on earlier items is grossly impaired

Episodic Impairments

Data from Greene et al. (1996).

34


Although AD patients have great difficulty acquiring new

information, forgetting rates match those of normal elderly

Kopelman (1985):

Task:

Matched picture recognition performance to normals’ (at a 5-

minute delay) by increasing exposure time

Re-tested picture recognition after 24 hours

Results:

Equivalent performance for AD patients and control elderly

individuals

Forgetting

35


Hodges, Patterson, and Tyler (1994) found that the degree of temporal lobe atrophy predicts deficits in semantic memory, as measured by a battery testing:

Picture (objects or animals) naming

Picture–name matching

Describing characteristics of named/pictured objects

Verifying sentences about objects

The semantic deficits in AD are not as severe as they are for semantic dementia, in which:

Episodic memory is relatively spared

Atrophy primarily occurs in the left temporal lobe

Damage in AD tends to be more medial

Semantic Difficulties

36


Study Task Finding

Heindel et al. (1989) Motor skill:

Pursuit rotor

•AD patients were worse to

begin with

•Yet, they improved at the

usual rate

Moscovitch (1982) Skill learning:

Mirror reading

Negligible impairment in

improvement rate for AD

patients

Fleischman et al. (1997) Priming:

Lexical decision

Normal priming

Fleischman et al. (1997) Priming:

Stem completion

Impaired priming, unlike in

classic amnesia syndrome

Beauregard et al. (2001) Priming:

Stem completion

• Normal priming with shallow

processing

• Reduced priming with deep

processing

Salmon et al. (1988) Semantic priming:

Cued associate

Reduced priming

Implicit Memory

37


Working memory is relatively less impaired than episodic memory;

however, there are modest deficits in:

Digit span

Corsi block tapping (visuo-spatial memory)

AD patients can maintain small amounts of material over unfilled

delays, so long as they can use the phonological loop to rehearse

Articulatory suppression causes rapid forgetting

Normal elderly individuals are only affected by intellectually demanding

filler tasks (e.g. counting backward by threes)

The capacity for sustained attention is not significantly compromised

Working Memory

38


Baddeley et al. (1986)

Task:

Matched digit load to

normal performance

Also matched secondary,

nonverbal rotary pursuit

task

Had to perform digit span

task either:

Alone

Simultaneously with the

tracking task

Results:

Young and normal elderly:

A slight performance decrease in dual-task condition

AD patients:

Showed a drastic decrease in the dual-task condition

Deficits increase as disease progresses (Baddeley et al., 2001)

All three groups behave similarly:

In the single-task condition, regardless of difficulty level

Working Memory

39


Donepezil, Rivastigmine, and

Galantamine

Inhibit cholinesterase

Prevents the breakdown of

acetylcholine

A neurotransmitter that normally

is depleted in AD

In the disease’s early stages:

Rely on preserved procedural and implicit memory to teach skills

Errorless learning

Fading cues

Remember: ―JOHNNY‖

Fill in ―JOH_ _ Y‖

Fill in ―J_H_ _ Y‖

Fill in ―J_ _ _ _Y‖

Use simple memory aids like

Message boards

Calendars

Modify the environment to make it clear where things should go

Pharmacological Behavioral

Treatment

40


Spector et al. (2000)

Improved performance on specific areas trained

Does not generalize to everyday memory performance

Reduced depression

Reality Orientation Training (ROT)

Helps the patient orient in time and place

Reminiscence Therapy

Helps patients maintain a sense of personal identity

Incorporates photographs and other reminders of their past life

Can have them construct a personal life-story book

Can be done in groups

Facilitates patient–therapist interactions

Training Programs

41

Chapter 13nalvarado/PSY335 PPTs/Baddeley... · 2015. 7. 21. · Memory as We Age An irony –comparing our own current memory with our past memory requires memory. People are less

Documents