Download Memory - Wiley

PSYCHOLOGY
Third Edition
by
Drew Westen
PowerPoint  Presentation
Chapter 6
MEMORY
John Wiley & Sons, Inc.
Lecture Outline





Memory and mental representations
Working memory
Long-term memory
Encoding issues
Forgetting
© 2002 John Wiley & Sons, Inc.
Memory

Memory is the process by which we
observe, store, and recall information
 Memories may be visual, auditory, or tactile

Memory processes may involve multiple
systems
 Conscious
 Automatic
© 2002 John Wiley & Sons, Inc.
Mental Processing

Mental Representations: A mental model
of a stimulus or category of stimuli
 Sensory representations
• Image of a dog
• Sound of a gun shot
 Verbal representations
• Concept of “Freedom”
• Involve neural activation different from that of
sensory representation
 Motoric representations
• Memories of motor actions
– Swinging a tennis racket
© 2002 John Wiley & Sons, Inc.
The Information Processing
Model of Memory
© 2002 John Wiley & Sons, Inc.
Standard Memory Model


This metaphor views the “the mind as a
computer”
Model assumes that memory consists of 3
stores:
 Sensory registers
• Iconic (visual)
• Echoic (auditory)
 Short-term memory (STM)
 Long-term memory (LTM)
© 2002 John Wiley & Sons, Inc.
Characteristics of STM

STM is a variant of memory that is of limited
duration:
 Information in STM fades after 20-30 seconds
(without rehearsal)

STM has limited capacity storage
 STM capacity is about 7 items of information
• Capacity is constant across cultures

STM Involves rehearsal
 Maintenance: information is repeated
 Elaborative: information is related to other
knowledge
© 2002 John Wiley & Sons, Inc.
Rehearsal aids LTM
(Figure adapted from Rundus, 1971)
© 2002 John Wiley & Sons, Inc.
LTM




LTM refers to the representations of facts,
images, actions, and skills that may persist over
a lifetime
LTM involves retrieval of information
LTM is theoretically limitless in capacity
The serial position curve supports the existence
of STM versus LTM
 Primacy effect reflects LTM
 Recency effect reflects STM
© 2002 John Wiley & Sons, Inc.
The Serial Position Curve
Recalled from
STM
Recalled from
LTM
(Figure adapted from Atkinson & Shriffrin, 1968)
© 2002 John Wiley & Sons, Inc.
Working Memory

Working memory is temporary storage and
processing of information used to
 solve problems
 respond to environmental demands
 achieve goals

Working memory may consist of three
modules
 Visual Memory Store
 Verbal Memory Store
 Central Executive
© 2002 John Wiley & Sons, Inc.
Working Memory Stores

Visual memory store
 A temporary image (20-30 sec) that provides
information about the location and nature of objects

Verbal memory store
 Involves storage of verbal items
• Limited capacity
• Shallow: Items are processed in order of presentation and
are subject to interference

Working memory stores are independent
 Brain damage may alter visual but not verbal
© 2002 John Wiley & Sons, Inc.
Working Memory and LTM

Evidence supporting a distinction between
working memory and LTM
 Working memory is easily accessed, but is limited
in capacity
 Neurological studies in which brain damage
impairs memory
• LTM impairment: person shows normal working
memory, but cannot transfer information to LTM
• Working memory deficit: person has a memory span of
2 digits, but normal LTM
 Chunking: LTM information is used to increase
item size in working memory (e.g. IBM, USC, CIA)
© 2002 John Wiley & Sons, Inc.
Prefrontal Cortex and Working Memory

Working memory involves
activation of the prefrontal
cortex
 Holding an image in working
memory (memory delay)
activates the prefrontal cortex
(Figure adapted from Courtney et al., 1997)
© 2002 John Wiley & Sons, Inc.
Varieties of LTM

Declarative memory
 Semantic: “generic” knowledge of facts
 Episodic: memories of specific events
• Autobiographical


Procedural memory: for skills
Explicit memory: Conscious retrieval of
information
 Recall versus recognition

Implicit memory: Skills, conditioned learning,
and associative memory
© 2002 John Wiley & Sons, Inc.
Overview of Long-Term Memory
© 2002 John Wiley & Sons, Inc.
Studies of Everyday Memories


Laboratory memory studies can be artificial
(timing, what is memorized)
Studies of everyday memory examine the
 Function of memory
• Our intent as we learn information
– Male vs. female memory study
 Emotional significance of memory
• Emotional memories may involve different neural
mechanisms than do neutral memories
 Prospective aspect of memory
• Emphasis is on time
© 2002 John Wiley & Sons, Inc.
Functional Aspects of Memory

Recall for information
may be a function of
our interest in the
information:
 Men show better
recall for workbench
construction details
than details on how to
make a shirt…
© 2002 John Wiley & Sons, Inc.
Encoding in Long-Term Memory

Storage of information in LTM requires
encoding as a function of meaning
 Match between encoding and accessibility

Levels of processing: Notion that encoding
can be
 Shallow: the physical aspects of the stimulus
 Deep: the meaning of the stimulus
© 2002 John Wiley & Sons, Inc.
Encoding Issues

Encoding specificity principle:
Idea that ease of retrieval of a
memory depends on match of
encoding with retrieval
 Poor recall if shallow learning is
examined using a deep
processing technique
• Student who reads multiple choice
items in test book and then takes
an essay exam will likely not do
very well

Spacing of learning is
important
 Spaced learning leads to better
recall of information
© 2002 John Wiley & Sons, Inc.
Figure adapted from Herrmann et al., 1992)
Mnemonic Devices

Mnemonic devices add additional cues for
retrieval to enhance memory
 Method of Loci
• The contents of a physical location that you are
familiar with is linked to the items you want to
recall
 Peg Method
• Imagery is combined with a verbal rhyme
– “One is a bun” (imagine a quart of milk in a bun…)
 SQ3R Method
• Survey, question, read, recite and review
© 2002 John Wiley & Sons, Inc.
Networks of Association

LTM is organized in clusters of information
that are related in meaning
 The network is composed of interconnected
nodes
 A node may contain thoughts, images,
smells, emotions, or any other information
 Mnemonic devices allow one to add concepts
to existing networks
© 2002 John Wiley & Sons, Inc.
An Example of Interconnected
Nodes
© 2002 John Wiley & Sons, Inc.
Hierarchical Storage

Nodes in LTM may be
organized in a hierarchy
 Broad categories contain
narrower categories

Hierarchical storage can
lead to retrieval errors
 “Which is farther north Seattle or Montreal?”
© 2002 John Wiley & Sons, Inc.
Forgetting


Forgetting refers to the
inability to recall previously
learned information
Ebbinghaus documented
the rate of forgetting of
information
 Initial rate of forgetting is
high and then trails off...
© 2002 John Wiley & Sons, Inc.
Memory Accuracy

Memory is subject to errors and biases
 Memory can be primed
• Study in which subjects were presented with a
list (slumber, nap, bed) of words that were
related to the word “sleep”
– Most subjects recalled the word sleep even though
that word had not been presented to them
 Memory is altered by emotional factors
• Study of recall of high school grades
– Students misremembered their D’s but recalled their
A’s
© 2002 John Wiley & Sons, Inc.
“Seven Sins of Memory”







Memories are transient (fade with time)
We do not remember what we do not pay
attention to
Our memories can be temporarily blocked
We can misattribute the source of memory
We are suggestible in our memories
We can show memory distortion (bias)
We often fail to forget the things we would like
not to recall (persistence of memory)
© 2002 John Wiley & Sons, Inc.
Memory Misrecall
(Figure adapted from Bahrick et al., 1996)
© 2002 John Wiley & Sons, Inc.
Theories of Forgetting

Decay theory
 Memory is like a fading neural trace that is weakened
with disuse

Interference theory: conflict between new and
old memories
 Proactive: old memories interfere with recall of new
information
 Retroactive: new memories interfere with recall of
old information

Motivated forgetting implies that forgetting can
avoid painful memories
© 2002 John Wiley & Sons, Inc.
Copyright
Copyright 2002 by John Wiley & Sons, Inc., New
York, NY. All rights reserved. No part of the
material protected by this copyright may be
reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying,
recording, or by any information storage and
retrieval system, without written permission of the
copyright owner.
© 2002 John Wiley & Sons, Inc.