Transcript Ch07x

Chapter 7
Long-Term Memory: Encoding,
Retrieval, and Consolidation
Some Questions to Consider
• What is the best way to store information in longterm memory?
• What are some techniques we can use to help us
get information out of long-term memory when
we need it?
• How is it possible that a lifetime of experiences
and accumulated knowledge can be stored in
neurons?
• How can the results of memory research be used
to create more effective study techniques?
Getting Information Into LTM
• Encoding: acquiring information and
transforming it into memory
• Retrieval: transferring information from
LTM to working memory
• Maintenance rehearsal
– Repetition of stimuli that maintains
information but does not transfer it to LTM
• Elaborative rehearsal
– Using meanings and connections to help
transfers information to LTM
Levels of Processing Theory
• Memory depends on how information is
encoded
• Depth of processing
– Shallow processing
• little attention to meaning
• focus on physical features
• poor memory
– Deep processing
• close attention to meaning
• better memory
Levels of Processing Theory
Beware of Circular Reasoning!
• Which task causes deeper processing?
– Using a word in a sentence
– Deciding how useful an object might be on a
desert island
• Depth of processing has not been defined
independently of memory performance
– Therefore, this is circular reasoning
Other Factors that Aid Encoding
• Visual imagery
• Self-reference effect
• Generation effect
• Organizing to-beremembered
information
• Relating words to
survival value
• Retrieval practice
Organization, Comprehension, and Memory
• Bransford & Johnson (1972)
• Presented participants with difficult-to-comprehend
information
– Experimental Group 1 first saw a picture that
helped explain the information
– Experimental Group 2 saw the picture after
reading the passage
– Control Group did not see the picture
• Group 1 outperformed the others.
– Having a mental framework of comprehension
aided memory encoding and retrieval
Organization, Comprehension, and Memory
Retrieval Practice
• Which results in a stronger memory trace?
– Re-reading the material
– Being tested on the material
• Roediger and Karpicke (2006) had participants
read a passage and then either
– Reread the passage (rereading group)
– Take a recall test (testing group)
• Then tested recall after a delay; testing group
performed better
• Testing Effect
Retrieval Practice
Retrieving Information from LTM
• Retrieval: process of transferring information
from LTM back into working memory
(consciousness)
– Most of our failures of memory are failures to
retrieve
Retrieving Information from LTM
• Cued-recall: cue presented to aid recall
– Increased performance over free-recall
– Retrieval cues most effective when created by the person who uses
them
Encoding Specificity
• We learn information together with its context
• Baddeley’s (1975) “diving experiment”
– Best recall occurred when encoding and retrieval
occurred in the same location
Encoding Specificity
State-Dependent Learning
• Learning is associated with a particular
internal state
– Better memory if person’s mood at encoding
matches mood during retrieval
Improving Learning and Memory
• Distributed versus massed practice effect
– Difficult to maintain close attention throughout a
long study session
– Studying after a break gives feedback about what
you already know
Matching the Cognitive Task
• Transfer-appropriate
processing:
phenomenon whereby
the results of a memory
task will be better if the
type of processing used
during encoding is the
same as the type during
retrieval
• Morris et al. (1977)
Consolidation
• Transforms new memories from fragile state
to more permanent state
– Synaptic consolidation occurs at synapses,
happens rapidly
– Systems consolidation involves gradual
reorganization of circuits in brain
• Muller and Pilzecker (1900)
Consolidation
Information Storage at the Synapse
• Hebb (1948)
– Learning and memory represented in the brain by
physiological changes at the synapse
– Neural record of experience
Information Storage at the Synapse
• Long-term potentiation (LTP)
– Enhanced firing of neurons after repeated
stimulation
– Structural changes and enhanced responding
Information Storage at the Synapse
Consolidation
• Standard model of
consolidation
– Retrieval depends on
hippocampus during
consolidation; after
consolidation
hippocampus is no
longer needed
– Reactivation:
hippocampus replays
neural activity
associated with
memory
The Fragility of New Memories
• Retrograde
amnesia: loss of
memory for
events prior to
the trauma
• Graded amnesia:
memory for
recent events is
more fragile than
for remote events
Consolidation
• Multiple trace hypothesis
– Questions the assumption that the hippocampus
is important only at the beginning of consolidation
– The hippocampus has been shown to be activated
during retrieval of both recent and remote
memories (Gilboa et al., 2004)
– The response of the hippocampus can change
over time (Viskontas and coworkers, 2009)
Are Memories Ever “Permanent”?
• Reactivation and reconsolidation evidence
from research on animals
– Occurs under certain conditions
• Human memory is a “work in progress”
Improving Learning and Memory
• Elaborate - associate what you are learning to
what you already know
• Generate and test – The generation effect
• Take breaks
– Memory is better for multiple short study sessions
(the spacing effect)
– Consolidation is enhanced if you sleep after
studying (in other words, no all nighters!)
• Avoid the “illusion of learning”
– Familiarity does not mean comprehension