Transcript Choice reaction time

Attention (Continued) & Memory
Lecture 4
October 3, 2007
Today’s Lecture
• What is speed of processing?
• What causes age-related slowing & what can
older adults do about it?
• Driving
• Language processing
• How does aging affect different types of memory?
• How does memory function in everyday
situations?
• How do older adults perceive their memory?
• What can older adults do to help their memory?
Article by May & Hasher (1998)
• Inhibition hypothesis: Originally presented
by Hasher & Zacks in 1988.
• Can you think of everyday situations in
which failing to inhibit information might
be problematic?
• Synchrony or time-of-day effects:
Differences in age.
• Testing these components on thought and
action, and on tasks that rely well-learned
vs.. new responses
Hasher & May article
•
•
•
•
•
•
•
•
What is a synchrony effect? How does it seem to be related to
inhibitory control?
How does the circadian rhythm of the average young adult and older
adult differ?
On a test of priming for sentence endings, what were the general
patterns of performance? Was the ability of young and old participants
to suppress non-target information different? Did testing at peak and
non-peak times have an effect?
How can researchers tell that failure in inhibition of irrelevant thoughts
rather than failure to activate the right thoughts seem to cause the
errors made? Is there any exception to that phenomenon?
On a test of motor activation and inhibition, how did the young and old
adults differ in their performance? Was it consistent? Was it across all
tasks that were given?
As the tone onset increased in the evening condition, what happened
to the performance of each group? Why is this an important finding?
What are the main conclusions of the article found in the general
discussion?
Can you think of any practical implication for these findings in how
older adults organize their daily activities?
Main Findings in Experiment 1
•
•
•
Performance of younger adults in the
morning (non-peak time) is similar to that
of older adults in the morning (peak
time).
Young adults are able to discard irrelevant
ideas at peak times, but not at off-times,
while older adults appear unable to do so.
How can researchers tell that failure in
inhibition of irrelevant thoughts rather
than failure to activate the right thoughts
seem to cause the errors made? Is there
any exception to that phenomenon?
Stroop Effect
black
green
red
blue
black
blue
green
blue
blue
yellow
green
yellow
black
red
red
blue
yellow
green
blue
yellow
red
blue
green
green
Stroop Effect
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
xxxx
Stroop Effect
green
black
blue
yellow
black
blue
black
green
red
blue
yellow
red
green
brown
black
blue
yellow
green
blue
red
black
green
blue
yellow
Main Findings Experiment 2
• Inhibitory efficiency in a motor test: Better
early in the day for older adults and later in
the day for young adults.
• Measure in morning: Often hard to
differentiate between the 2 groups.
• Same pattern seen in neuropsychological
tests tasks that rely on frontal functioning.
Main Conclusions
• Time of day has an effect on inhibitory
control, regardless of age.
• Seen for both a task involving verbal
material & motor types of tasks.
• When asked to perform tasks with welllearned information: Synchrony effect not
apparent.
• Can you think of any practical implication
for these findings in how older adults
organize their daily activities?
What Are Some Changes in Divided
Attention?
• Equalizing the amount of attention given
to the two tasks, can minimize agerelated differences (Somberg and
Salthouse, 1982).
• No differences on easy tasks, but as
complexity occur, differences occur.
• When extensive practice is allowed,
minimize age differences.
How Do Older Adults Perform on Tasks
of Sustained Attention?
• Vigilance performance appears to be affected by
age, while vigilance decrement is not.
• What accounts for differences?
– Fitness level important to older but not
younger adults
– Level of uncertainty affect older but not
younger adults’ performance
• What kinds of jobs rely on this kind of attention?
Should there be a mandatory age of retirement in
those professions?
What Is Speed of Processing?
• Shows how quickly and efficiently the brain
completes early information processing.
– Sensory memory & attention.
Long-Term
Memory
External
Stimuli
Processing
Forgetting
Retrieval
Sensory Memory
Short-Term
Memory
Rehearsal
Forgetting
Elaboration and
encoding
Initial
Response
How Can You Measure Speed of
Processing?
• Simple reaction time: Involves responding to
one stimulus as fast as possible
• Choice reaction time: Offer more than one
stimulus and require a response to each in a
different way
• Complex reaction time: Making many
decisions about when and how to respond
(driving tasks)
Choice Reaction Time
Slowing Down: The One Truth About
Aging
• Slowing is a generalized finding, but large
interindividual differences in performance.
• Variability across trials: Predictive of poorer
performance?
• Do all components of mental processing
slow equivalently? Is slowing generalized
or specific to a few processes?
Do all components of mental processing
slow equivalently?
• Or is slowing generalized or specific to a
few processes?
• Dominant age effect across processes that
tends to dwarf local effects so this general
effect needs to be parcelled out.
• Other important distinctions are now
studied:
– 1) Computational vs. control processes
– 2) Behind behaviour, there is always the brain.
– 3) Quantitative changes in speed, but also
changes in qualitative performance.
What Causes Age-Related Slowing?
• Neural Networks
– Computer analogy—the more
connections the slower the task.
• Information Loss
– Myerson et al. model based on four
assumptions.
• Do older adults have any skills to help
compensate for those attentional changes?
Driving In Older Adults
• 60% of Canadians older than 65 years old have a
driver’s license.
• Older drivers have the highest ratio of collisions
per travelled distance (Retchin & Anapolle, 1993).
• Useful Field of Vision (UFOV)
– Extent of field of vision available in a brief
glance
– UFOV predictor for 13% of accidents
• Highway Accidents
– Not age per se, but decreased skills
Driving and Highway Safety as
Information Processing
• Problems facing older drivers
– Trouble reading highway signs and instrument
panel
– Difficulty seeing the road
– Problems reaching for seatbelt
– Trouble backing up (range of neck motion)
– Changing lanes
– Noting signs and warnings
– Turning properly
– Yielding the right of way
Hogan, D.B. (2005). Which older adults are competent to drive? Approaches to officebased assessment. Canadian Family Physician, 51, 362-368.
How Is Language Comprehension
Affected By Age?
• Presbycusis
• Age-related decrements
– Speech recognition
– Speech discrimination
• Context is important to age-related speech
comprehension
What Is The Role of Language in
Language Processing?
• Richness and extensiveness of encoding
– Encoding - connecting what you hear
with what you know
• Encoding deficits
– No age differences in encoding basic
lexical information
– Older adults tend not to create
distinctive context-specific coding. They
use sentence context specific coding cues
Bilingualism and Aging
• Bilingualism appears to attenuate the
decrease in ability to inhibit irrelevant
stimuli experienced in aging (Bialystok et
al., 2004).
• This effect was seen in the Simon task,
which measures the ability to ignore an
irrelevant feature.
Simon Task
When you
see BLUE,
tap with
your left
hand.
When you
see RED,
tap with
your right
hand.
Results of the Simon Task
• Equated participants on simple reaction time.
• Older adults were overall slower than younger
adults but bilinguals were faster, particularly
in older adults.
• The more complicated the task, the more
payoff for bilinguals.
What Are The Characteristics of Working
Memory?
• Limited capacity.
• Critical in encoding, storage, and retrieval.
• Older adults, presented with multiple tasks,
do poorly compared to younger.
• Evidence that these differences relate to
performance on more complex cognitive
tasks.
Long-Term
Memory
External
Stimuli
Processing
Forgetting
Retrieval
Sensory Memory
Short-Term
Memory
Rehearsal
Forgetting
Elaboration and
encoding
Initial
Response
What Is Long-Term Memory?
• Ability to remember extensive amounts of
information from a few seconds to a few
hours to decades
• Explicit and implicit memory
• Episodic memory
– Recalling information from a specific event or
time
• Semantic memory
– Learning and remembering the meaning of
words and concepts
What Are The Age-Related Changes
Observed in Episodic Memory?
• Age differences in episodic memory: Recall vs.
Recognition
• Overall, older adults perform worse than
younger on tests of episodic memory recall
• On recognition tests, the differences are
smaller because provide more context to
support recall.
What Are The Age-Related Changes
Observed in Semantic Memory?
• Fairly well-preserved until mid 80s
• Minimal change related to age in processes
such as language comprehension,
knowledge structure, and general
knowledge activation
• There is age-related decline in accessibility
and speed of retrieval
• Tip of the Tongue (TOT) experiences
What is Remote Memory?
• Information kept for a very long time in
memory is termed remote memory.
– e.g: Asking someone who is 80 years old about
his/her wedding day, first day of school or names
of celebrities in the 40s.
What is Autobiographical Memory?
• Often seen as a form of episodic memory
related to self.
• Information that must be kept for a very
long time, and allows us to look at remote
memory.
• Autobiographical memory
– Remembering information and events from
one’s own life: If become semantic, easier to
recall.
– Flashbulb memories
What is Implicit Memory?
• Change in task performance that is
attributable to having been exposed to
information at an earlier time but does not
involve active, explicit memory
• Slight age differences that, if present, favour
younger adults
• Distinctions in perceptually and conceptually
based tests
Encoding and Retrieval in Aging
• Rehearsal
– Making connections between incoming
information and information already known
• Research has shown complex relation
between elaboration at encoding and age.
– Task variables could affect encoding or
retrieval, such as divided attention
– Emotional content
• Use of strategies
– Organize
– Establish links
Encoding and Retrieval in Aging
• Cognitive neuroscience & imaging have
provided a lot of possible paths to find
answers...
• Hemispheric asymmetry reduction in older
adults (HAROLD model)
• Research is important for three reasons:
1.Age-related decrements are complex.
2.Not due to changes in a single process.
3.Theories must take individual differences into
account.
Is Memory Always Accurate?
• Older adults seem more vulnerable to
generate false memories. e.g.: The false
fame experiment.
• Older adults are less apt to remember the
source of information they have learned,
making them more vulnerable to effects of
familiarity.
• However, one caveat to that finding is
presented in the Rahhal et al. (2002) paper.
Are There Sources Older Adults Can
Remember?
• Perceptual (voice) vs. Conceptual (truth,
value statement about the person in
photograph) information
• Young adults were more reliable when it
came to voice source, but there was no age
difference for truth/value statement.
• Older adults are better at remembering
affective, value-based details than
perceptual ones.
More About Source Memory
• May & Rahhal (2005) found further evidence that
only emotional conceptual information supports
recall (e.g. remembering if food is rotten or not at
a wedding reception), while percepetual and nonemotional conceptual do not (e.g.: remembering
the location of food items or temperature at
which food should be served.)
• Same for remember car information: colour
(perceptual) vs. class (non-emotional conceptual)
vs. safety (emotional conceptual).
Can The Presentation of a Memory Task
Influence Performance?
• In older adults, instructions make a big
difference.
• Rahhal et al. (2001): Instructions which
emphasized the memory nature of a task led
to a poorer performance than when it did
not… Why?
• Generating better strategies?
Memory for Text
• Text clearly organized: Fewer age-related
differences. Why?
• Rapid presentation, highly unpredictable or
unorganized material, and densely presented
material have adverse effects.
• Differences disappear when speed of
presentation is controlled.
• Personal beliefs or knowledge influence recall.
Example- Logical Memory Subtest of WMS
Memory for Situation Models
• Younger and older adults are similar in ability
to construct and update situation models
– Exception: older adults take longer to memorize
maps and have slower reading times
• Older adults use integrative or interpretive
style for non-fables, whereas younger adults
use more literal or text-based style
• No age differences are found for fables
• Benefits of prior knowledge is similar for older
and younger adults
• Social context matters in the way stories are
retold—for older adults, it depends on the
listener.