Download Long-Term Memory: Overview

Cognitive
Psychology
Long-Term Memory: Overview
Lesson V: Long-Term Memory
module 23
University of Idaho
Cognitive
Psychology
© Steffen Werner - 2004
Long-term Memory.23. 1
What are we going to talk about?
The structure of long-term memory
– Taxonomy of content
– Semantic coding
– Serial position effect
Memory consolidation
– How are memories formed
– Transfer of information from STM to LTM
How can we probe long-term memory?
– Explicit memory tests
– Implicit memory tests
University of Idaho
Cognitive
Psychology
© Steffen Werner - 2004
Long-term Memory.23. 2
What are we going to talk about?
Constructive nature of memory
– Associations in memory
– Large units of knowledge (Schemata)
– Memory distortions
Modality of long-term memory
– Sensory modalities and long-term memory
– Dual code theory: Propositional vs. imaginal codes
– Context effects in memory
Awareness of our memories
– Memory strategies / Mnemonics
– Meta-cognitive knowledge
University of Idaho
© Steffen Werner - 2004
Long-term Memory.23. 3
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Cognitive
Psychology
What are we going to talk about?
Specific memories
– Autobiographical memory
– Mnemonists
– Eye-witness testimony
– Flashbulb memories
Neuroscience of long-term memory
– The role of different brain centers for the
formation and storage of human memories
– What kind of neural processes are the basis for
memories
University of Idaho
Long-term Memory.23. 4
© Steffen Werner - 2004
Cognitive
Psychology
What do we remember?
A taxonomy of LTM content
Declarative memory
– Things we remember and can talk about
– Semantic memory: factual knowledge
– Episodic memory: memories of personal experience
Non-declarative memory
– Procedural memory: How to do things
(motor skills, perceptual learning)
– Associations (priming, conditioning)
University of Idaho
© Steffen Werner - 2004
Cognitive
Psychology
Long-term Memory.23. 5
The serial position curve
Primacy
University of Idaho
© Steffen Werner - 2004
Recency
Long-term Memory.23. 6
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Cognitive
Psychology
The serial position effect: interpretation
Primacy effect
– Less influenced by proactive interference
– First items are consolidated into LTM
Recency effect
– Less influenced by retroactive interference
– Items still in WM / STM
Modifications of the shape of the curve
– Delays in recall will reduce recency effect
– Fast presentation rate might interfere with
consolidation and reduce primacy effect
– Amnestics might show selective impairment of
primacy effect
University of Idaho
Cognitive
Psychology
© Steffen Werner - 2004
Long-term Memory.23. 7
A little demonstration…
Take 3 minutes and …
– Write down the names of all the animals you know
– Time yourself and stick to three minutes
– Make a mark every 30 seconds so you know how far
you have gotten for each half minute
University of Idaho
Cognitive
Psychology
© Steffen Werner - 2004
Long-term Memory.23. 8
What is stored in LTM?
The role of semantic code
Multimodal storage
– LTM by definition stores information in many
specialized forms, e.g., visual information, auditory
information, procedural information
Semantic code
– LTM relies heavily on meaning of material
– Formation of associations between items in LTM
– Higher false alarm rate for semantically related
words in recognition tasks
– Categorical structure of recall - grouping of similar
objects into categories
University of Idaho
© Steffen Werner - 2004
Long-term Memory.23. 9
3
Cognitive
Psychology
Metacognition
Ability to think about our cognitive processes
– We generally know whether we know something or not,
even before we can answer the question
– We can think about strategies to get to a particular
memory content
– We can use memory or mnemonic strategies to
remember more information
The tip-of-the-tongue phenomenon
– Sometimes, we know that we know something, but we
cannot get there all the way
– Ability to describe the content (e.g., long vs. short
name, “sounds like”, associations)
– Ability to predict time it will take to retrieve knowledge
University of Idaho
Cognitive
Psychology
© Steffen Werner - 2004
Long-term Memory.23. 10
Memory consolidation
General principle
– Not all information is retained in LTM
– Information has to be consolidated
– Integration with existing memories strengthens
memory trace
Multiple pathways
– Content of memories is stored in different locations
all across the brain, depending on modality and type
of memory
– Declarative: stored in cerebral cortex; important role
of hippocampus in consolidation
– Procedural: Role of cerebellum and basal ganglia
University of Idaho
Cognitive
Psychology
© Steffen Werner - 2004
Long-term Memory.23. 11
Levels of Processing Theory
(Craik & Lockheart, 1972)
Memory storage varies by the type of encoding
– The type of processing of to be remembered material
determines how much of the material is later recalled
– Information that is processed shallowly is not retained
as well as information that is processed more deeply
Examples
– Processing of physical features of words (capitalized?)
– Phonological processing (rhyming)
– Semantic processing (what is the meaning of word?)
– Self-referential processing (how does it related to me?)
University of Idaho
© Steffen Werner - 2004
Long-term Memory.23. 12
4
Cognitive
Psychology
Memory as a constructive process
Memories are integrated
– Memories are integrated into larger structures
(schemata) reflecting expectations / beliefs
– Memory for meaningful material is best
– Memory is biased by expectations and “fills in”
missing pieces
Examples
– Bartlett’s experiments on Schemata (1932)
– Cultural framework of autobiographical memories
Memory for text
– Schemata relevant for construction of
understanding in text comprehension
University of Idaho
Cognitive
Psychology
© Steffen Werner - 2004
Long-term Memory.23. 13
Memory loss: Amnesia
Retrograde amnesia
– Loss of memory for events prior to a trauma
– Mild retrograde amnesia occurs frequently
(e.g., after a concussion)
– Retrograde amnesia can diminish over time
Anterograde amnesia
– Loss of memory for events after a trauma
– Best known case: H.M.
Effects of amnesia
– Affects declarative memory (explicit memory)
– Procedural memory and implicit memory can still
be intact
University of Idaho
© Steffen Werner - 2004
Long-term Memory.23. 14
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