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Attention and Memory
Attention I
 Visual attention operates through both
automatic and effortful processes
 Parallel processing
 We automatically process all stimuli in a display when
we’re paying attention to only a single dimension (e.g.,
color)
 This allows us to quickly identify a target (i.e., it “pops
out”), regardless of the number of distractors
 Serial processing
 We need to engage slow, effortful search processes when
asked to identify targets defined by the conjunction of
two dimensions (e.g., color and letter identity)
Attention II
 Attention allows us to select a single source of
auditory stimulation from amongst many possible
sources and ignore all other incoming messages
 That is, attention functions like a filter
 Conversely, we’re not very good at attending to
more than one auditory message at a time
 We do process some unattended information, but in a
weaker form than we process attended information
 Unattended, but weakly processed, information can grab
your attention when that information is relevant to your
goals
 The cocktail party phenomenon
Attention III
 Change blindness
 We often miss large objects in our visual field when we are attending to
something else
 Although most people do not believe they can fail to see large objects
right in front of them, numerous studies show this is the case
Information-Processing Model of Memory
 Sensory memory: it’s purpose is to hold an internal
copy of physical information just long enough for the
system to select something in particular to attend to;
that information then gets transferred to . . .
 STM: our conscious workspace
 Processes that control the flow and makeup of information
have their locus in STM (e.g., coding, rehearsal, retrieval
strategies…)
Sensory memory
 Representational format: Modality-specific
 Iconic memory: visual sensory memory
 Echoic memory: auditory sensory memory
 Haptic memory: touch sensory memory
 Duration
 Iconic memory: 250 ms
 Echoic memory: 2-3 seconds
 Capacity: Modality-dependent
 Forgetting: Information decays if not further
processed
Testing the duration and
capacity of iconic memory
 A letter array is
displayed for 50
ms
 In the whole
report condition,
subjects try to
report all the
letters
 In the partial
report condition,
subjects report
only a single row
of letters
Duration and capacity of iconic memory
Short-term memory
 Duration: 20 sec when you are distracted and can’t
rehearse
 Unlimited when maintaining information through repetition
that you want to remember, like a phone number; termed
“maintenance rehearsal”
 Format: Visual verbal stimuli are stored in STM in
an acoustic format
 Sound-alike errors: when they can’t remember, people might
say V instead of E, but not F instead of E.
 Capacity: The magical number 7+2
 Chunking (1 4 9 2 1 7 7 6 1 9 4 5)
 Expertise
 Retrieval: We retrieve information from STM by using a
serial exhaustive search, rather than a serial self-terminating
search
Forgetting
from short-term memory
 Decay theory of forgetting
 Memory traces dissipate as time passes and those memories
are not used (see sensory memory)
 Interference theory of forgetting
 Memories are lost when they are bumped out or replaced by
the formation of new memories
 Experiment (for the result, see the next slide)
 Some subjects sees 12 items, at a rate of 1 item per second.
Total time: 12 seconds
 Other subjects also see 12 items, but at a rate of 4 items per
second. Total time: 3 seconds.
 Decay theory predicts more forgetting in the first condition
because more time has gone by.
 Interference theory predicts equal forgetting in both
conditions because the same number of new memories are
being formed.
Support for the interference theory of
forgetting in STM
Working Memory
 STM was described as a
single system responsible
for information flow and
control
 However, STM is also used
for comprehension of
language, problem solving,
and visual imagery (e.g.,
mental rotation task)
 Baddeley revamped the
idea of STM and renamed it
“working memory”
 Working memory is a set of
independent subsystems
that share attentional
resources
Some working memory findings
 Memory span task: listen to simple elements and immediately report in the
order of their presentation
 K.F.: memory span is impaired, but IQ is spared
 Dual task methodology: have subjects do two tasks concurrently, each of
which taxes the interdependent systems (e.g., the auditory working
memory slave system and the central executive)
 Findings
 (1) As auditory working memory load increases from saying “the the
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the …” (concurrent articulation task), to saying “1 2 3 4”, to holding
six random digits in memory, reasoning task performance decreases
(2) If subjects do a memory span task and a concurrent articulation
task, for which auditory working memory is responsible, memory
span performance decreases
(3) Concurrent articulation eliminates sound-alike errors for visually
presented materials because the scratch-pad is used instead
(4) Concurrent articulation does NOT affect memory span for visual
objects that cannot be named because storage of the visual objects
does not require auditory working memory
(5) Word-length effect: Memory span is shorter for longer words
because longer words more quickly consume the limited resources of
auditory working memory
Mental rotation in visuo-spatial
working memory
Subjects were asked
whether the letter was a
normal R or a mirrorreversed R.
The farther away from
vertical, the longer it
took for the subjects to
decide.
Conclusion: Subjects
rotate a mental image of
the stimulus to it’s
vertical position before
deciding.
Serial position effect
 Since we cannot directly observe them, how do we
know these two mental structures -- called STM and
LTM -- actually exist?
 Experiment
 All subjects are presented 15 words, one at a time, for 2
seconds each.
 Some subjects are asked, immediately after the words have
been presented, to recall as many words as they can, in any
order.
 Serial position effect
 Memory performance is better for the first few words (the
“primacy effect”) and the last few words (the “recency effect”)
that have been presented.
 For other subjects, there is a delay of 30 seconds after the
list has been presented.
 During this delay, the subject may, for example, be asked to
count backwards by 4’s from 569.
 See next slide for result
Short-term vs. long term memory
 The 30 s delay
eliminated the
recency effect, but
did not impair the
primacy effect.
 This indicated that
the recency effect
must be due to
STM, while the
primacy effect
must be due to
LTM.
Long-term memory (LTM)
 Memory for information that is no longer being rehearsed.
 If a person is distracted for a couple minutes from rehearsing a new
phone number, yet remembers the number, then it must have been
stored in LTM.
 Capacity: infinite
 Duration: permanent
 Forgetting: retrieval failure
 Memories are available, but not necessarily accessible
 Format: meaning (semantic) and visual (episodic)
 At least for explicit long-term memory
 You’re using your explicit long-term memory when you intentionally
retrieve information from a specific episode (episodic memory) or you
intentionally retrieve a fact (semantic memory)
 You’re using your implicit long-term memory when you unintentionally
retrieve information from a specific episode and the retrieval of that
information affects your current behavior
 See slides 19, 21, and 22.
Long-term memory
Three key phases of the LTM process
 Encoding
 The mental processes we use to process
information determine the strength and
longevity of memory for that information.
 Storage
 There are many different types of long-term
memory.
 Retrieval
 The circumstances under which one tries to
retrieve memories, such as the nature of the
memory test, influence the success of that
retrieval.
LTM Systems
Declarative (Explicit)
Long-Term Memory
 Conscious retrieval and declaration of
past events and known facts
 We often retrieve information from LTM into STM
and then consciously respond in a particular
manner
 Two forms of declarative memory
 Episodic memory and semantic memory
 Episodic memory
 Includes where, when, and to whom something
happened
 Reexperiencing, often in visual terms, of a past
event
Nondeclarative
(implicit) memory
 Unconscious (automatic) retrieval of
information that influences behavior; responses
are, in some respects, not mediated by STM
 Skills and habits: reading, typing, bike riding,
tying shoes, brushing teeth, washing dishes
 Priming: any influence of a single past episode
on current behavior that occurs without a
person’s intentional retrieval or awareness
 Simple conditioning: cat and can opener
 Nonassociative learning: Habituation and
sensitization
Explicit vs. Implicit memory
 Amnesic patients (like H.
M.) and normal controls
were tested for memory
for words that had been
previously studied
 Amnesics performed
poorly on the explicit
memory tasks
 Amnesic performance on
implicit memory tasks was
like that for control
subjects
 Conclusion: Amnesics can
form memories for studied
words – at least implicit
memories – even though
they can’t tell you what
words they’ve studied
Encoding into (explicit) LTM
 Four factors affecting the strength of (explicit)
LTM
1) Elaborative rehearsal (processing information for meaning)
promotes better LTM for facts than maintenance rehearsal
(i.e., rote rehearsal or repetition)
2) Regardless of how you rehearse, spaced rehearsal is better
than massed rehearsal

It’s better to study 1 hour of information for an hour at 3 different
times than for 3 hours all at one time
3) Dividing attention during encoding impairs LTM
4) Use of imagery to code information in a visual format also
promotes better LTM

Picture superiority effect: pictures are remembered better than
words
Semantic memory: Schemas
 Schema: Knowledge representations, built
through integrating similar experiences across
time, which allow us to predict the nature of
repeated activities (e.g., birthday parties) and
environments (e.g., offices)
 Schemas are used to construct long-term
memories of the stimulus at encoding and to
reconstruct long-term memories at retrieval
 Sometimes this can be beneficial, as in the following
passage from Bransford & Johnson (1972)
 Sometimes this can be costly, as in the following
Brewer & Treyens (1981) picture of the office
Read this passage before going to the next slide
 The procedure is actually quite simple. First you arrange
items into different groups. Of course one pile may be
sufficient depending on how much there is to do. If you have
to go somewhere else due to lack of facilities that is the next
step; otherwise, you are pretty well set. It is important not to
overdo things. That is, it is better to do too few things at once
than too many. In the short run this may not seem important
but complications can easily arise. A mistake can be
expensive as well. At first, the whole procedure will seem
complicated. Soon, however, it will become just another facet
of life. It is difficult to foresee any end to the necessity for
this task in the immediate future, but then, one never can
tell. After the procedure is completed one arranges the
materials into different groups again. Then they can be put
into their appropriate places. Eventually they will be used
once more and the whole cycle will then have to be repeated.
However, that is part of life.
Schema benefits
 When subjects read the preceding passage
without a title or when subjects were given a
title to the passage after they had read it,
comprehension scores and recall scores were
low.
 However, subjects given the title “Washing
Clothes” before reading the passage scored
twice as well in both comprehension and
recall tests.
Study this picture for 30 s before going to the next slide
List as many objects as you can recall
from the photograph you just saw.
Schema Costs
 Many subjects recall seeing books in the picture
of the office, when there are no books in the
picture.
 Another example
 Roediger & McDermott (1995)
 Present subjects with lists of words (e.g., bed,
rest, awake, tired, dream, wake, night, blanket,
doze, slumber, snore, pillow, peace, yawn, and
drowsy)
 Many subjects recall having heard the word
“sleep” in the list, even though it was not
presented
Semantic memory I
 Semantic memories are knowledge representations
that are built through integrating similar experiences
across time
 Each time you are told that the sun rises in the east leaves
an episodic memory of that event
 But once you have many episodic memories of being told
that fact, then you forget the episodes in which you learned
that fact and you just remember the fact itself
 This process is sometimes termed “abstraction” and the memory
left is sometimes described as an “abstract” form of memory
 Many different types of semantic memory
 Words and their meanings
 Facts: “George Washington’s face is on a $1 bill.”
 Categories: “A canary is a type of bird.”
 Schemas (see slides 24-29 for explanation)
Semantic Memory II: Semantic Networks
 Our semantic memory is
organized by meaning, like a
thesaurus
 In contrast, a dictionary is
organized alphabetically
 Each concept is represented
as a node
 When the word “red” is
presented, the node for red
becomes activated and, if
that activation is sufficient,
you
 Become conscious of that word
 Become conscious of the
meaning of that word
 Are able to say that word or
respond to that word
Semantic Memory III
 Spreading activation
 When red becomes activated, the activation spreads from
red to other concepts that are connected to red
 Three examples of spreading activation at work
 Free association
 If you’re asked to say the first word that comes to mind when you’re
presented the word red, you’ll say blood or roses or fire engine or
apple or . . .; but you won’t say words that are unrelated to red
 Automatic activation of task relevant knowledge
 When someone says to you, “Please set the table for dinner.”, there
are many things left unsaid, such as what to set on the table, in what
arrangement to set those things, how many places to set, etc. Your
semantic memory fills in that missing information when activation
spreads from table and dinner to related concepts.
 Semantic priming (see next slide)
Semantic Memory IV:
Semantic Priming
 Semantic priming
 Imagine a task where you are presented two words in
succession and your task is to say just the second word; the
experimenter is going to measure how long it takes you to
say the second word
 If a word unrelated to red, like the word box, is presented before
the word red, you will be relatively slow to say the word red (it will
take you about ½ sec)
 However, if a word related to red, like the word apple, is presented
before the word red, you will be relatively fast to say the word red (it
will take you about 1/3 sec)
 The difference in speed is called a semantic priming effect
 The reason you’re faster to say red after apple than after box is
because the activation of apple spread to red and, as a result, red
already had a head start when the word red was actually presented.
Encoding-Retrieval Similarity
 Enhancing the similarity between conditions at
study and test can improve the rate at which
information is successfully retrieved from LTM.
 The physical environment (i.e., environmental context)
 The stimulus environment
 Encoding specificity principle
 Emotional state (mood)
 Physiological state (drugs)
 Psychological state (depression)
 Cognitive processes that are involved in processing
information
 Transfer-appropriate processing
Searching for the engram I
 Engram: physical site of memory storage
 The medial (i.e., middle) section of the temporal lobes is
important for many aspects of declarative memory
 The medial temporal lobe includes cortical structures, such as the
rhinal cortex, and subcortical structures, such as the hippocampus
and amygdala
 Consolidation
 Transfer of information from short-term to long-term memory
 Reconsolidation
 After you retrieve a memory from LTM, you must re-store that memory
back into LTM
 When you re-store a memory back into LTM, it is often altered by the
mental environment into which it had been retrieved
 Spatial memory
 Taxi drivers, especially experienced ones, have a larger hippocampus
than people that do not drive taxis
Brain and Memory
 The limbic system is
critical for memory
formation and recall
 Hippocampus: Critical
for forming new
explicit (conscious)
memories
 Amygdala: Important
role in emotional
memories
 H.M.’s hippocampus was
removed in both
hemispheres and he
suffered from
anterograde amnesia
H.M.’s surgery
Searching for the engram II
 The frontal lobes are also important for many
aspects of memory
 Damage to the frontal lobes impairs
 Memory for the time sequence of events
 Memory for the source of information (i.e., where, when,
and from whom information was learned)
 The ability to deeply process information (i.e., process it
for its meaning)
 Working memory and leads to an inability to follow a
planned sequence of steps, such as using a recipe to
bake a cake
Searching for the engram III
 The amygdala plays an important role in memory
 It does so by controlling the effects of memory modulating
neurotransmitters, such as norepinephrine
 This is especially true during events associated with reward, fear or
other emotions, and arousal
 These events cause an increase in norepinephrine and an increase in
the strength and durability of memory
 Occasionally, these processes can produce overstrong memories or can
“burn these events into memory”
 Often, patients with post-traumatic stress disorder (PTSD), cannot
forget events that they would like to forget
 Drugs (e.g., propranolol) that block norepinephrine receptors
reduce the duration and strength of emotional memories
Forgetting: The three sins
 Transience
 Forgetting over time
 Ebbinhaus’s forgetting curve (see next slide)
 Decay vs. interference
 Interference! (see slides 10 & 11)
 Types of interference
 Proactive vs. retroactive (see slide 42)
 Absentmindedness
 Inattentive or shallow encoding of events
 Change blindness
 Blocking
 A temporary inability to remember something that is
known because some other, similar, information is
interfering with your memory
 Broussard Park? Bourgeois Park? No, it’s Burroughs Park!
 Tip-of-the-tongue phenomenon
Ebbinghaus’s Forgetting Curve
 Over the first three days,
the rate of forgetting is
very high
 % correct drops from 57%
to 25%
 Over the next 27 days,
the rate of forgetting is
very low
 % correct drops from 25%
to 21%
 In summary, the rate of
forgetting is initially very
high, but becomes very
low
Interference and Forgetting
Distortion: The sins of
persistence and misattribution
 Persistence
 The resurgence of unwanted memories that we would like
to forget
 See slide 39 for the role of the amygdala and norepinephrine in
creating such memories
 Misattribution of source (and source amnesia)
 The source of information
 Knowing who told you something (or when, where, and how you
learned something) is important for evaluating that information
 We often misremember the source of information (source
misattribution) or forget the source of information (source
amnesia) and, when we do so, this leads us to evaluate
that information differently
 The false fame effect
 The sleeper effect
 Cryptomnesia: Unintentional plagiarism
 False memories
Distortion: The sin of suggestibility
and the misinformation effect
 Suggestibility
 The misinformation effect (Loftus)
 Subjects are shown a slide show in which a Datsun runs a stop sign
and hits a pedestrian.
 Later they are asked “Did another car pass the Datsun as it reached
the yield sign?”
 Later, 30% more of these subjects incorrectly said that they had
been shown a slide with a yield sign than if they had not been
asked the “leading question”, many with a high degree of
confidence.
 The misinformation effect implies that eyewitness
testimony many often be unreliable
 For the first 130 people nationwide whose guilty verdict was
overturned because of DNA evidence, mistaken eyewitness
identification played a role in over 75% of the cases.
 http://www.innocenceproject.org/understand/
 Eyewitnesses that are wrong are often just as confident,
and sometimes even more confident, than eyewitnesses
that are correct
Distortion: The sin of suggestibility
and illusory memories
 Illusory memories
 Students (N = 24) were presented a booklet in
which there were four stories of childhood events.
 Three of these stories were true.
 The three true stories had been gathered by previously
contacting the family of the student.
 One of the stories, about being lost in a mall, was
false.
 Subjects were asked to try to remember these
events and to describe what they remembered in
detail.
 If they didn’t remember, they were told to say so.
 After first reading the booklet, 7 of 24 subjects
“remembered” being lost in the mall.
 In follow-up interviews, 6 of 24 subjects continued
to remember being lost in in the mall.
Distortion: Implications of
illusory memories
 Recovered memories or false memories?
 According to Freud, repressed memories are
memories of (typically) traumatic events that people
have forced from their conscious memory into their
unconscious
 People sometimes claim to recall traumatic events
(such as childhood sex abuse) after having forgotten
these events for many years
 If these events really occurred, were forgotten, and were
later remembered, then these are called recovered
memories.
 If the memories of these events were really the product of
suggestions made by an unwitting therapist to the patient,
then these are called false memories (a special type of
illusory memory).
Distortion: The sin of bias
 People’s memories of their past attitudes, behaviors,
or knowledge are often adjusted (biased) to be
consistent with their current attitudes, behaviors, or
knowledge.
 Subjects who are newly persuaded of the value of brushing
their teeth report that they brushed their teeth more often
in the past two weeks than those that were not persuaded
(Ross, 1989).
 “I really knew all along how important it was to brush my teeth
and, in fact, I’ve been doing so.”
 “It is common for caterpillars to become butterflies and
then to maintain that in their youth they had been little
butterflies. Maturation makes liars of us all,” (Vaillant,
1977).
Other important memory concepts
 Flashbulb memories
 Very clear, visual, detailed memories of a new, important, emotional event.
 They are not necessarily 100% accurate, but they are more accurate than
memories for everyday events.
 Autobiographical memory
 As we age, we tend to remember most our adolescence and early adulthood
 We especially remember transitional firsts, such as 1st and 4th years of college
 Prospective memory
 Memory for things that need to be done in the future
 Remembering to do some thing at a particular time and remembering what to do at
that time
 Keeping the script for the to-be-done activity in an activated state helps prospective
memory
 Metamemory
 People’s knowledge of their own memory skills and abilities
 The accuracy with which people guess how likely it is that they will remember
something or how effective some memory strategy or learning strategy may be for
them
 Your metamemory has failed you when you think you’ve studied enough for an
exam, but then do poorly.