AGING AND MEMORY
• The aging of America
• Conventional wisdom on aging and
memory
• Neurobiological changes [demo]
– Neural mass decreases, 5-10% / decade
• Shrinkage; atrophy of “white matter”
• Frontal lobes particularly vulnerable
• Some atrophy, little cell loss, in
hippocampus
– Decreases in neurotransmitters
• Acetylcholine from basal forebrain
• Dopamine receptors in frontal lobes
– Decreased blood flow, metabolism
– Less “functional activation”
• Left anterior frontal during encoding
• Right anterior frontal during retrieval
HOW MEMORY CHANGES
• The myth of inevitable, global
decline
• Deficits may be due to other factors:
–
–
–
–
–
–
–
General health problems
Medication
Depression
Self-concept, sense of “efficacy”
Educational level
Motivation and task engagement
Specific disease (e.g., Alzheimer’s)
• Age-related declines seen . . .
More in
Than in
Kinds of memory:
declarative
procedural
explicit
implicit
episodic
semantic
recent
remote
Types of tasks:
complex
simple tasks
unfamiliar
familiar tasks
distractor
no distractor
divided
full attention
recall
recognition
• Processes that are especially
vulnerable:
– Speeded information processing (the
“general slowing hypothesis” of Salthouse)
– Effortful, strategic encoding, more so
retrieval (the “reduced resources
hypothesis” of Craik)
– Source monitoring and memory
– Executive function, elaborative
encoding and retrieval
Simon (1979): Cued recall
The farmer drove the truck
Free
Cued
Young
.50
.70
Old
.25
.25
(Cherry, et al. 1993): contextual cues
and “causal elaborations”
• The grimacing man held the cheese..
. . as he reached for a salt cracker.
(nonexplanatory context)
. . as the mousetrap caught his finger.
(explanatory context)
Type of context
nonexplanatory
explanatory
Base
Full
Base
Full
Young
.22
.47
.21
.76
Old
.06
.20
.10
.59
– Executive control in working memory
(Baddeley)
Salthouse & Babcock (1991) :
“computation span”
Mean Span
8
6
digit span
4
computation
span
2
0
20 yr
70 yr
Study Task
– Attentional allocation, inhibition of
potential distractors from task or
memory (Hasher & Zacks)
• Broader context-priming effects
• Greater stroop interference
• More PI intrusions
AGING AND MEMORY
• Taking the edge off aging
– Stay healthy and engaged
• Regular aerobic exercise
• Nonroutine, challenging daily activities
– Provide meaningful organization and
structure to tasks
– Allow adequate time for encoding and
retrieval
– Minimize distractions, keep tasks simple
– Provide extensive practice on new
tasks, continued practice on old skills
• Reminiscence in the elderly
– Seeing coherence in one’s life story
– Providing continuity over the
generations
Mental Exercise and
Mental Aging
• The “use it or lose it’ hypothesis
– Evidence of “protective function” of
mental activity Rutgers Newsletter
– Salthouse (06): the need for longitudinal
comparisons
Suggests that mental activity does not
Affect rate of decline with age
Alzheimer’s and Memory
• Demographics
– C. 4 million afflicted, accelerates with
aging (50% of 85 yr+)
– 3rd leading cause of death
– Costs approaching $100 billon annually
• Etiology
– Ultimate causes unknown
– Immediate cause is degeneration of
neural structure
• Loss of mass, neurons
• Impaired acetylcholine levels
• Plaques of neural debris
• Neurofibrillary tangles within neurons
• Early symptoms of dementia
– Memory loss: misplacing things,
forgetting to do things, disorientation,
repetition in converstation, retrieval of
familiar words and names
– Procedural memory: deficits in
performance of “simple” routine tasks;
dressing, cooking, etc
– Poor judgment: e.g., wrong clothes,
inappropriate social behavior
• Progressive Dementia
– Increasingly severe impairment in
cognitive functioning; semantic
memory, language, autobiographical
memory
– Loss of motor control
– Loss of self
– The challenge to families
fMRI and aging
Memory Retrieval (Miller, 03)
Top row: young adult (20 yr)
Bottom row: old adult (70 yr)
Source Memory Problems and
Aging
• Session 1:
• view nonfamous faces
• detect repetitions
• Session 2 (next week):
• view S1 faces, other famous and
nonfamous faces
• judge fame
Bartlett, et al (1991)
False fame judgments
Proportion false
"famous"
0.50
0.40
0.30
Old
Young
0.20
0.10
0.00
zero
One
Study exposures
Two
Episodic Memory Deficits in
Alzheimer’s Disease
La Rue, 1992: WMS loss (%)
Paired associate recall
Paired associate recognition
34
5
Memory for visual detail
65
Story memory
80