Transcript Document

HUMAN DEVELOPMENT 1
PSYCHOLOGY 3050:
Memory Development (Ch 8)
Dr. Jamie Drover
SN-3094, 864-8383
e-mail -- [email protected]
Winter Semester, 2015
Representation of Knowledge
• Information in the long-term store can be
represented in two ways (Tulving, 1985).
• Declarative memory: facts and events. Two types.
• Episodic memory: memory for episodes (explicit).
• Semantic memory: knowledge of language, rules,
concepts, facts, and events.
Representation of Knowledge
• Nondeclarative/Procedural Memory: Knowledge of
procedures that are unconscious.
• Can include familiar routines.
• AKA implicit memory as it is unavailable to conscious
awareness.
– Can only be assessed indirectly.
• Different brain areas may be responsible for different
memory types.
– Domain-specific
Representation of Knowledge
• Nondeclarative/Procedural Memory: Knowledge of
procedures that are unconscious.
• Can include familiar routines.
• AKA implicit memory as it is unavailable to conscious
awareness.
– Can only be assessed indirectly.
• Different brain areas may be responsible for different
memory types.
– Domain-specific
Memory Development in Infancy: Preference for
Novelty as an Indication of Memory
• Usually assessed using the habituation/
dishabituation paradigm.
• Researchers also use preference-for-novelty
paradigms.
• Infants are shown a novel stimulus and a familiarized
one.
• Preference for the novel stimulus is seen as memory
for the familiar one.
Memory Development in Infancy: Preference for
Novelty as an Indication of Memory
• Fagan (1973, 1974) found that 5and 6-month-olds will show
visual memories for stimuli
following brief exposures.
• These memories can last two
weeks.
• Spence (1996) had mothers of 1month-olds read nursery rhymes
over a 2 week period.
• Using the sucking rate paradigm,
infants will adjust sucking rate to
hear the familiar rhyme even
after a 3 day delay.
Memory Development in Infancy: Conjugate
Reinforcement Procedure
• Rovee-Collier (1999) tied a ribbon to an infant’s
ankle and connected it to a mobile.
Memory Development in Infancy: Conjugate
Reinforcement Procedure
• In the first 3 minutes, the ribbon is not connected to
the mobile (baseline nonreinforcement).
• In the next 9 minutes, the ribbon and mobile are
connected.
• Following delays, infants are placed back in the crib
and their foot is connected to the ribbon.
• If they show a high kicking rate, it reflects memory.
Memory Development in Infancy: Conjugate
Reinforcement Procedure
• 3-month-olds were tested using this procedure.
• They showed no forgetting after 8 days.
• In related research, 8-week-olds showed that they
could retain these memories for 2 weeks.
• Rovee-Collier has also focused on the role of context
in memory
– How similar must the learning environment and testing
environment be to remember?
Memory Development in Infancy: Conjugate
Reinforcement Procedure
• Infants were seated in a playpen with a very
distinctive cloth.
• Infants underwent the standard kicking training.
• For the test, infants could be placed in the same
context (same cloth) or in a different context
(different cloth).
• When in the same context, infants demonstrate far
better retention.
Memory Development in Infancy: Conjugate
Reinforcement Procedure
• Older infants have been
tested with the train task.
• Infants sit in front of a
miniature train set and
learn that they can move
the train around by pressing
a lever.
• Infants are tested after a
delay by sitting in front of
the lever which is now not
connected to the train.
How Long Do Infants’ Memories Last?
• Infants’
memories
last longer
with age.
Deferred Imitation
• Infants’ long-term memory has been tested using
deferred imitation.
• Imitating a model after a significant delay.
• Infants can remember novel actions for as long as
one year.
• Bauer (2002) tested infants with a 3-step task.
– Placed a bar across two posts
– Hung a plate from the bar
– Struck the plate with a mallet (p. 311)
How Long Do Infants’ Memories Last?
• Following delays (1-12 months), infants were given
the materials and tested for deferred imitation (see
Table 8-5, p. 312).
– Rate of deferred imitation was higher in older children.
– Older children can handle longer delays.
How Long Do Infants’ Memories Last?
• Deferred imitation likely relies on several brain areas
– hippocampus, prefrontal cortex, structures within the
temporal lobe.
– The hippocampus underlies the earliest deferred imitation.
– To retain information following long delays, these areas
need to mature and coalesce.
Infantile Amnesia
• The inability to recall information from early
childhood.
– We are unable to remember events that happened before
we were 3.5 or 4 years of age.
• We lack autobiographical memories.
– Personal and long-lasting memories which are the basis for
one’s personal life history.
• Usher and Neisser (1993) found that the earliest
memory for college students was about 2 years of
age.
Why Can’t We Remember Early Events?
• Two explanations.
1. Information is not stored for long-term retention
before 2 years of age.
2. The information is encoded differently.
• The second explanation is more likely.
• When we are older, our minds are no longer like
those of infants.
–
We now use verbal symbols.
Why Can’t We Remember Early Events?
• Infants are tested on recall of motor memories,
whereas children and adults are tested on verbal
memories.
• Infants can not convert memories into verbal
memories.
• Simcock and Hayne (2002) showed children (27-39
months) sequences of actions and interviewed them
6 and 12 months later.
Why Can’t We Remember Early Events?
Why Can’t We Remember Early Events?
• After the delay, although they had the verbal ability,
most children did not use it to describe the previous
experience.
• They did so only if they had the vocabulary to
describe the event when it was experienced.
• More verbally sophisticated children at the time of
the initial test verbally recalled the event.
• Children could not translate earlier preverbal
experiences into language.
Why Can’t We Remember Early Events?
• But why can 3- and 4-year-olds recount verbally
events that happened years before?
• Howe and Courage (1993) believe that in order to lay
down and retrieve autobiographical memories, a
sense of self is needed.
– This develops in the preschool years.
– Unless events can be related to the self, they can not be
retrieved later.
Implicit Memory
• Unconscious memories. Memory without
awareness.
• Implicit and explicit memories appear to be governed
by different brain systems.
• The hippocampus is involved with explicit memories.
Implicit Memory
• HM had hippocampal brain damage.
• He could learn new skills with no memory of being
taught those skills.
• His implicit memory was intact.
• He couldn’t recall learning it.
– He lacked explicit memory.
Implicit Memory
• There appear to be few age differences on implicit
memory.
• Researchers test this using fragmented pictures that
the child has to identify.
Implicit Memory
• Hayes and Hennessy (1996) showed 4-, 5-, and 10year-old children a series of pictures on one day and
asked them to identify the picture or asked to
answer questions about the item.
• Two days later, the children were shown some of the
previous pictures and some new ones to identify in
the fragmented picture task.
Implicit Memory
• Older children identified more pictures and
recognized more that they had seen earlier.
• The priming effect was equal for children of all ages.
• The degree to which they identified old pictures
more quickly than new pictures.
– They could do this even if they could not remember seeing
the pictures two days earlier.
• i.e., implicit memory.
Implicit Memory
• Newcombe and Fox (1994) showed 9- and 10-yearolds pictures of 4- and 5-year-olds, some of whom
were there classmates.
• They had to recognize their classmate (explicit
memory) while their skin conductance was being
measured (implicit memory).
• There was no difference on skin conductance
between children who did well or poorly on the
explicit task.
The Development of Event Memory
• Things that happen to us during the
course of everyday life.
• It’s explicit, but encoding is
unintentional.
• How do children remember events?
• The event must be attended and
perceived.
• Young children pay attention to
different aspects of an event than
do adults.
– Children sometimes attend to
trivial events.
The Development of Event Memory
• Event memory is constructive in nature.
• We recall gist implying that we transform the event.
• Our memory for events is influenced by our previous
knowledge.
Script-Based Memory
• Preschool children organize their
event memory in terms of scripts.
• A form of schematic organization
of real-world events organized in
terms of their causal and temporal
characteristics.
– Fast food restaurant script
• Young children and even preverbal infants appear to organize
information temporally into
scripts.
Script-Based Memory
• Bauer and Mandler (1989) showed
infants from 11.5 to 20 months a
sequence of events.
• Children were then given the
materials.
• Children re-enacted the sequence
of events in the same temporal
order they had been shown.
• Because children use scripts they
tend not to remember specific
details.
– See Fivush and Hamond (1990)
on p. 279.
Script-Based Memory
• Children tend to recall routine information rather
than novel aspects of a special event.
• Nelson (1996) believes that script-based memory has
adaptive value by permitting children to predict the
likelihood of events in the future.
– Memory is designed to retain information about frequent
and recurrent events.
Children as Eyewitnesses: Age Differences
• In typical studies, children observe an event or
activity and are not told that they will be asked to
remember what they view.
• Later they are asked what they remember.
• They are asked free recall questions, cued recall
questions, and recognition questions.
How Much do They Remember, and How Accurate are They?
• Preschool children remember only a small
proportion of the event in response to free-recall
questions.
– What they recall is highly accurate and central to the
event.
• When given general cues, they recall more
information; more correct and incorrect facts.
• These false memories can persist after long delays
and when asked to recognize.
How Much do They Remember, and How Accurate are They?
• False memories can not be based on verbatim
information; it is based on gist and is, therefore,
resistant to forgetting.
How Long Do Memories Last?
• With delays of one month or less, children of all ages
remember about the same proportion of accurate
and inaccurate information as they did originally.
• After 6 month delays, 6 year-olds’ recall is less
accurate than that of adults.
How Long Do Memories Last?
• According to fuzzy trace, there is a greater rate of
decay of verbatim (exact) memories relative to gist
(false) memories.
Factors Influencing Children’s Eyewitness Memory
• Factors include IQ, incentives to be accurate,
intermediate levels of stress, and emotionally
supportive mothers.
The Role of Knowledge
• Children who know more about medical procedures
remember more about the procedure.
• Ornstein et al. (1998) tested 4- and 6-year-old
children’s recall of a mock physical exam.
Factors Influencing Children’s Eyewitness Memory
• The exam included typical and atypical features.
• Children were interviewed about the exam after a 12
week delay.
• They were asked open-ended questions followed by
increasingly specific questions.
• Also asked specific questions about things that did
not happen.
Factors Influencing Children’s Eyewitness Memory
• Typical features are more likely to be recalled
correctly than atypical features.
– The children likely had a script for the exam.
• Children were more likely to correctly reject
nonevents for the atypical features.
• Children were more likely to say false events
occurred when they were typical as opposed to
atypical.
Factors Influencing Children’s Eyewitness Memory
Characteristics of the Interview
• Children recall little in response to open-ended free
recall questions, but it is accurate.
• They recall more with cues, but are more inaccurate.
• What about anatomically correct dolls?
• Bruck et al. (1995) interviewed 3-year-olds following
a medical exam.
Factors Influencing Children’s Eyewitness Memory
• Half received a genital exam whereas the other half
did not.
• Using the doll they were asked whether the doctor
touched their genitals.
– Half of the group that received the exam said yes.
– Half of the group that did not receive the exam said yes.
– 50% of the children who did not receive the exam pointed
to the anal or genital region.
Factors Influencing Children’s Eyewitness Memory
• How warm or supportive an interview is can also
influence accuracy.
• 4- to 6-year-old children who had high levels of
stress showed increased accuracy when tested by an
emotionally supportive interviewer.
• Showed reduced accuracy when questioned by a
non-supportive interviewer.
Age Differences in Suggestibility
• To what extent are children susceptible to
suggestion?
• Are children more suggestible than adults and what
factors influence suggestibility?
• Children do indeed appear to be more suggestible
than adults.
How Do Children Respond to Misleading Questions?
• Cassel and Bjorklund (1995) showed 6- and 8-yearold children, and college students a video of a boy
taking a girl’s bike without permission.
• All subjects were interviewed 15 mins, 1 week, and 1
month later.
• They were asked misleading questions or positiveleading questions in the later interviews.
• 6- and 8-year-olds follow the lead of the interviewer.
How Do Children Respond to Misleading Questions?
• They had more incorrect responses to misleading
questions and more correct responses to positiveleading questions.
• In the final interview, they were asked leading
questions by one examiner and then opposite
questions by another examiner.
• The children typically changed their minds to agree
with the second examiner.
How Do Children Respond to Misleading Questions?
• Goodman and Clarke-Stewart (1991) had children
observe a janitor clean toys or play with them
inappropriately.
• Children in the first condition were asked questions
that suggested the janitor had played with the toys
inappropriately.
• Two-thirds of the children followed these
suggestions and did not alter this new interpretation
even when questioned by their parents.
How Do Children Respond to Misleading Questions?
• Why are young children so susceptible to
misinformation?
• According to Fuzzy-trace theory, verbatim traces
decay rapidly and are not available later when the
suggestive questions are asked.
• Children are unable to reject erroneous information.
• Source monitoring: being aware of the source of info
one knows or remembers.
How Do Children Respond to Misleading Questions?
• Young children often have difficulty monitoring the
source of their memories.
• They often have difficulty determining whether they
performed an act or just imagined it.
• They often attribute actions done by others to
themselves (Foley et al., 1993).
• Six-year-olds who are poor at source monitoring are
more prone to the effects of suggestion.
False Memory Creation
• How easy is it to get children to believe events that
did not happen?
• Ceci et al. (1994) interviewed 3- and 6-year-old
children over an 11-week period about events that
might have happened to them.
• Few children admitted experiencing these events
early in the study, but this increased throughout the
study.
– This was especially the case of for young children.