1. PSY 368 Human Memory
Development of Memory

2. Development of Memory infancy childhood adulthood elderly
Our focus so far
This Week

3. Development of Memory Outline for this week
Studying infants & children
Basic Processes and Capacities
Methodological issues
Memory in the Elderly
What abilities decline?
Why do they decline?
Recognition and Recall
Implicit and Explicit memory
Episodic memory
Standard Model
Sensory
STM/WM
LTM

4. Development of Memory Outline for this week
Studying infants & children
Basic Processes and Capacities
Methodological issues
Memory in the Elderly
What abilities decline?
Why do they decline?
How do we test infants?
Non-Nutritive Sucking
Habituation/Dishabituation
Conditioning

5. Development of Memory Outline for this week
Studying infants & children
Basic Processes and Capacities
Methodological issues
Memory in the Elderly
What abilities decline?
Why do they decline?
Will cover next time

6. Studying Infants Recognition Memory in infants
Non-Nutritive Sucking method (infants will adjust sucking rate to get preferred stimuli)
DeCasper & Spence (1986)
Had mothers read stories everyday to fetuses during final 6 weeks of pregnancy
After babies were born tested to see if babies preferred familiar story over novel one
Results: babies recognized and preferred the familiar stories
(most-likely the prosody, of the story)
Unlikely that this was based on the 4 days of experience

7. Studying Fetuses Recognition Memory in the womb
We experience language before we are even born
DeCasper, et al (1994)
Fetal heart monitor

8. Studying Fetuses Recognition Memory in the womb
We experience language before we are even born
DeCasper, et al (1994)
Fetal heart monitor
Had mothers read rhymes everyday to fetuses during weeks of pregnancy
After 38th week, two rhymes were played to the fetuses (but mom couldn’t hear it)
Same rhyme
Different rhyme

9. Studying Fetuses Recognition Memory in the womb
We experience language before we are even born
DeCasper, et al (1994)
Fetal heart monitor
Had mothers read rhymes everyday to fetuses during weeks of pregnancy
After 38th week, two rhymes were played to the fetuses (but mom couldn’t hear it)
Same rhyme
Different rhyme

10. Studying Fetuses Recognition Memory in the womb
We experience language before we are even born
DeCasper, et al (1994)
Had mothers read rhymes everyday to fetuses during weeks of pregnancy
After 38th week, two rhymes were played to the fetuses (but mom couldn’t hear it)
Fetal heart monitor
Decreased fetal
heart-rate
Same rhyme
Different rhyme
Baby learned something about the rhyme before it was born!

11. Studying Infants Recognition Memory in infants
2 weeks post-habituation: 2-month-olds prefer to look at a novel scene or object
Habituation technique

12. Studying Infants Habituation technique Habituation/Dis-habituation:
familiarize with A
then present A or B
if infant dis-habituates to B, then infant remembers A and can discriminate between A and B
Preference for novelty:
familiarize with A
then present A and B together
if infant shows a preference for B, then infant remembers A and prefers B because it is a novel stimulus
The basic idea is that if the infant prefers, or responds differently to the novel stimulus, it remembers the original stimulus.

13. Studying Infants Recognition
Strauss & Cohen (1978): 5-month-olds’ ability to habituate to size, color, form & orientation
5-month-olds were habituated to a large, black arrow pointing down
shown new object, e.g., large white arrow pointing down (measure preference/looking time)
Results:
Immediate: remembered all 4 attributes;
15 minutes later: remembered form and colour;
24 hours later: remembered only the form
Thus, infants have a fairly durable memory of the object seen but other properties less enduring

14. Studying Young Kids Recognition
Perlmutter & Lange (1978) - 2 year olds – recognition of pictures was better than adults
Brown & Scott (1971) – 4-year-olds’ picture memory was at 100% accuracy; even 25 items between 2 exposures
Sophian & Stigler (1981) – tested young preschoolers (2y11m), older preschoolers (4y6m) , 1st graders (6y3m) & college students recognition memory for faces.
Found no change between the preschool ages, but improvement over older groups
Recognition is generally quite good very early in development

15. Studying Infants Recall Object permanence
the understanding that objects continue to exist even when they cannot be seen, heard, or touched
8-12 months will:
search for hidden objects
show anxiety in parents’ absence
Maybe even earlier (video)

16. Studying Infants Recall
Deferred Imitation (e.g., Meltzoff, 1985, 1995 & Bauer, 1997)
the ability to imitate a previously-seen behaviour hours or days later
Experimenter demonstrates a novel use of an unfamiliar toy.
After a delay, infants are given the toy.
If the infants display the novel behavior more than infants in a control group, they must remember the action they observed earlier

17. Studying Infants Recall
Deferred Imitation (e.g., Meltzoff, 1985, 1995 & Bauer, 1997)
Results: Range of activities and the time over which they remember and imitate grows in the first year
By 9-months : 24 hours later can imitate naturally occurring behaviors and those that are arbitrary, such as pressing a button to make a beeping sound
By 14-months : can imitate behaviors after even more time has passed, and will imitate unusual activities, such as viewing an adult press their forehead on a panel to make a light go on up to 4 months after seeing an adult do this
Thus, at this age, events are represented in long term memory and can be accessed months later.

18. Developing Memory Implicit and Explicit Memory
Much of the infant research into memory examines implicit memory
Rovee-Collier et al. conditioning experiments
Implicit memory in older kids
Hayes & Hennesey Fragmented picture task
Newcombe & Fox Picture recognition
But with children who are old enough to talk, research has focused on explicit memory.

19. Studying Infants Conditioning technique
Rovee-Collier: studies using mobile conjugate reinforcement procedure
Study with infants as young as 2 months old
Procedure (video)
A ribbon is tied between a mobile and an infant’s leg
Learn to kick to move mobile
Reactivation treatment
Questions:
How long can infants remember?
What is the role of context?

20. Studying Infants Conditioning technique
Rovee-Collier: studies using mobile conjugate reinforcement procedure
How long?
delay before test: 48 hours to 2 weeks
Results
No forgetting for up to 8 days
Kicking behaviour will be forgotten within 2 weeks if the event is not experienced again, but infants can retrieve the memory if it is appropriately cued

21. Studying Infants Conditioning technique
Rovee-Collier: studies using mobile conjugate reinforcement procedure
Role of context?
Study with 6-month-olds, 24 hour delay before test
Sides of playpen were draped with distinctive cloth
At test one group had same cloth surrounding playpen, other group had a different cloth
Results
"no change" group had a higher retention rate

22. Studying Infants Conditioning technique
Rovee-Collier: studies using mobile conjugate reinforcement procedure
Conclusions
Infants do, therefore, have some implicit/procedural memory
context plays a role in reinstating memory
Based on 6 more experiments further investigating the role of context, Rovee-Collier et el. concluded that infants don't respond to the context "as a whole", but rather to specific components of the context

23. Studying Young Kids Implicit Memory
Hayes & Hennesey (1996) study with and 10-year olds
Children were shown fragmented pictures and asked to identify them.
The same fragmented pictures along with some new ones.
Results:
Older children identified more pictures
BUT the priming effect (the degree to which old pictures were identified faster than new pictures) was the same for all ages.
Thus, with age, there was no improvement in implicit memory.

24. Studying Young Kids Implicit Memory
Newcombe & Fox (1994) study with 9- & 10-year-olds:
Children were shown pictures of preschoolers (some were former classmates)
Measure of explicit memory: they were asked "Is this a former classmate?”
Measure of implicit memory: changes in electrical conductance of the skin
Results: "performance" was poor (but greater than chance) on both explicit and implicit measures
BUT there was no difference in skin conductance between the children who did well on the explicit measure and those who did poorly
Thus, children who had poor explicit memory still implicitly "recognized" classmates just as much as children who had relatively good explicit memory.

25. Developing Memory Episodic Memory
Infantile amnesia - few episodic memories before age 3-4

26. Studying Young Kids Episodic Memory:
Infantile amnesia - few episodic memories before age 3-4
Children as young as 2 are able to talk about events that happened in the past (Fivush & Hamond, 1990; Nelson, 1984; Nelson & Ross, 1980)
By 3 or 4 years of age, children can answer questions with fewer prompts (Hamond & Fivush, 1991)
Event memory may be explained in terms of scripts, a knowledge structure containing information about the typical way in which an event happens

27. Developing Memory Episodic Memory
Infantile amnesia - few episodic memories before age 3-4
Several explanations have been proposed:
Not enough language to successfully store memories
Sense of self not developed enough, so no autobiographical timeline to use to organize memories
Unable to make use of durable gist memories

28. Studying Young Kids Episodic Memory: Autobiographical memories
Simcock & Hayne (2002)
Magic shrinking machine
In goes big toy, out comes identical small toy
Later asked to describe what happened, identify pictures, and re-enact the event

29. Studying Young Kids Episodic Memory: Autobiographical memories
Simcock & Hayne (2002)
Results
Youngest groups recalled less than older groups
Longer delays led to worse recall
Differences between the three measures. Worst recall on verbal task, best on re-enactments.
Used words only known at the original session to describe the task
Conclusions: Children have memories of early events, but may not have the language skills and knowledge to encode them

30. Studying Young Kids Iconic memory
Sheingold (1973) replicated Sperling with kids (5, 8, 11, and adults)
Array of 7 shapes; central pointer
flashed briefly (100 msec), then pointer
what was pointer pointing at?
varied delay between pointer and array: simultaneous, 0 (right after disappeared), 50, 100, 150, 200, 250, 500, 1000 msec

31. Studying Young Kids Iconic memory
Sheingold (1973) replicated Sperling with kids (5, 8, 11, and adults)
Results:
at 50 msec delay, no age effects
Conclusion:
5-years-olds can hold lots of info in sensory memory
capacity of sensory memory doesn’t develop
There were changes at other delays, suggesting differences in other stages of processing

32. Developing Memory Short-term memory Span Serial position
Encoding strategies
Rehearsal
Organization
Elaboration
Attention

33. Developing Memory Short-term memory: Span
The number of items that children can recall on the digit span task increases from around 2.5 at age 2, to 7 in adulthood

34. Developing Memory Short-term memory: Span
According to proponents of the working memory model, the duration of the phonological loop is a key constraint of how much information can be remembered
Hulme et al (1984)
Correlation between speech rate and memory span
But Cowan (1997), suggests that search time may also play a role (reflected in pauses btwn words)

35. Developing Memory Short-term memory: Serial position curve
6-years-olds show recency but not primacy, 9-year-olds show some primacy
High Recall
14+ years old
9-year-olds
6-year olds
May reflect different encoding strategies
Low Recall
Early Late
(Primacy) (Recency)

36. Developing Memory Short-term memory: Encoding strategies
Young children seem to be less efficient at encoding information (little or no primacy), probably due to differences in strategy usage
Rehearsal: repetitively naming information that is to be remembered
Organization: information to be remembered should be structured so that related information is placed together
Elaboration: embellishing information to be remembered to make it more memorable

37. Developing Memory Short-term memory: Rehearsal
Flavell, Beach, & Chinsky (1966)
Presented kindergarten, 2nd, and 5th grade children with sets of pictures of common objects and asked them to remember them.
During 15-sec. delay before each recall test, observed children's lip movements

38. Developing Memory Short-term memory: Rehearsal
Flavell, Beach, & Chinsky (1966)
Results
Both recall and rehearsal increased with age
10% of kindergarteners ---> 85% of grade 5 children.
Also, within a grade level, children who rehearsed more recalled more.
Conclusions
Rehearsal increases with age, and the frequency of rehearsal determines memory performance

39. Developing Memory Short-term memory: Rehearsal
Ornstein, Naus, & Liberty (1975)
Used an overt rehearsal procedure with 3rd, 6th, & 8th grade children:
Children were presented with a series of words, and told that they must repeat the most recently-presented word during the interstimulus interval (ISI), and that if they wish they may also practice other words during the ISI.

40. Developing Memory Short-term memory: Rehearsal - type changes with age
Ornstein, Naus, & Liberty (1975)
Desk, desk, desk, desk
Desk, man, yard, cat, man, desk, cat, yard
4. Desk
Man, man, man, man, man
Man, cat, yard, man, cat, yard
3. Man
Cat, cat, cat, cat, yard
Cat, yard, yard, cat
2. Cat
Yard, yard, yard, yard
Yard, yard, yard
1. Yard
Third-grade student
Eighth-grade student
Word Presented

41. Developing Memory
Short-term memory: Organization - organizing the items we want to remember into meaningful categories
Salatas & Flavell (1976)
Presented 1st graders with 16 pictures (4 from each of 4 categories).
Experimenter named the pictures, identified the categories, and placed the pictures randomly in front of the children.
Children were told to (physically) sort the pictures in a way that would help them remember them.
Result:
Only 27% of the children sorted the cards according to category.

42. Developing Memory
Short-term memory: Organization - organizing the items we want to remember into meaningful categories
Other, similar studies have found that:
Preschool children tend not to use this strategy - children as old as 8 years often fail to group the cards on the basis of meaning (instead, they group items randomly)
In the early school years, children do not spontaneously use the strategy, but they can be taught it and benefit from using it.
By the age of 10 or 11 are more likely to group on the basis of meaning, and they recall more items

43. Developing Memory Short-term memory: Elaboration
Generating relations between pairs of items so that memory for the items can be constructed in a meaningful way
Elaboration is not spontaneously used as a memory strategy until adolescence, and even then it is not common
Younger children can be taught to use elaboration but they do not get the same benefits with respect to increased recall as older children

44. Brief Summary Short-term memory: Encoding Strategies
Memory development between preschool years & adolescence involves age-related changes in the frequency of use and quality of strategies
Acquisition of new strategies, refinement of existing, & generalization to new situations

45. Developing Memory
Attention - Ability to selectively attend (and inhibit irrelevant) develops with age
Hagen & Stanovich (1977):
Presented Pairs of pictures
Ignore one & remember the other
Intentional Test: recall the central stimuli, as per instructions – recall increases with age
Incidental Test: recall the ones they were supposed to ignore
Results:
smaller age differences: after age 11, actually remember less of the to-be- ignored items
Conclusion: younger kids paying attention to irrelevant stimuli more than older kids

46. Developing Memory LTM - Use of content knowledge
Bauer & Mandler (1992)
tested babies 11.5 to 20 months
shown a sequence of events
later allowed to interact with the materials
e.g., putting a ball in a cup, inverting another cup on top, shaking cups
children re-enacted events in sequence shown

47. Developing Memory LTM - Use of content knowledge – scripts
Hudson & Nelson (1983)
Told children (4 & 5 yr olds) a story about a birthday party, but put some elements in wrong order
When asked to recall the stories, children often omitted or corrected the miss-ordered items

48. Developing Memory LTM - Use of content knowledge Chi (1978)
10 yr old chess experts vs. novice adults
For the children with chess expertise, an assortment of shaped pieces on a chequered board was not a random array of objects, but a meaningful situation encompassing multiple relationships between the pieces

49. Developing Memory LTM - Use of content knowledge
Dinosaur knowledge studies (Chi & Koeske, 1983; Gobbo & Chi, 1986)
5 dinosaur child experts & 5 child novices
Showed pictures of dinosaurs, asked them to tell all they knew about the pictured dinosaur
Experts and novices produced similar numbers of explicit propositions (which could be seen directly in pictures)
Experts produced many more implicit propositions (which could not be seen in the pictures)

50. Brief Summary Recall and Recognition developed early
Implicit memory developed early
Episodic last to develop
STM
Increase in strategies - rehearsal, organization
LTM
Increase in general knowledge over first 15 yrs
Kids use scripts & schemata

51. Aging
What abilities decline?
STM - slight decline

52. Aging What abilities decline? Recall - 20% over 40 yrs (25-65)
Recognition - little decline

53. Aging
What abilities decline?
Source judgments and encoding details

54. Aging What abilities decline? Prospective memory
no event-based declines (cues given)
time-based declines (self-initiated cues)

55. Aging Why do they decline? “Use it or lose it” (Disuse view)
Systems view - episodic declines first
Processing view
Speed
lack of inhibition
transfer-appropriate processing

56. Memory and Aging
Older adults learn more slowly
Remember less learned information
Declines by age 70
Timed tasks, unfamiliar tasks
Recall vs. recognition
Explicit memory tasks more trouble
Cognitively demanding tasks

57. Explaining Declines
Negative beliefs affect memory skills
Strategy use not spontaneous
Attention becomes more effortful (motivation)
Processing speed decreases
Sensory, health, and lifestyle changes
Cohort differences (age and IQ)
*Declines NOT universal

58. Fig 8. 9 Declines in memory skills in old age are not universal
Fig 8.9 Declines in memory skills in old age are not universal. In deaf culture and in Chinese culture, elderly people are not stereotyped as forgetful or senile. Perhaps as a result, Chinese elders perform almost as well as young Chinese adults on memory tasks, whereas in the United States, elders, especially in the hearing population, perform poorly.

59. adulthood It is all downhill from here…
Hit your 70s, your brain shrinks…
There is general cognitive slowing (probably) which accounts for some semantic memory problems
Episodic memory declines too
Could be due to encoding (Simon’s work)

60. Inhibition deficit hypothesis
More susceptible to interference
Longer reading times
More easily distracted using distractor tasks
Sustained activation of irrelevant material
In sum, it is probably a combination of overall cognitive slowing and a problem with inhibition

61. Summary of Development
Episodic last to develop and first to decline
Increase in general knowledge over first 15 yrs
Increase in strategies - rehearsal, organization
Study age changes with
• habituation
• longitudinal
• cross-sectional