Transcript Memory

Memory
Unit VII Modules 31-33
Memory
• We take our memory for granted until it does
not work correctly
• Our memory is what defines our life
• Our memory allows us to recognize family,
speak our language, find our way home, and
locate food and water
• It is our memory that allows us to enjoy an
experience and then mentally replay and
enjoy it again *
Memory
• Without memory there would be no savoring
past joys, no guilt or anger over painful
recollections
• We would live an enduring present with no
memory
• Each person would be a stranger, every language
foreign, every task a new challenge
• You would even be a stranger to yourself, lacking
that continuous sense of self that extends from
your distant past to your momentary present *
Memory
• Memory- the persistence of learning over time
through the encoding, storage, and retrieval of
information
• Encoding- the processing of information into the
memory system- for example, by extracting
meaning
• Storage- the process of retaining encoded
information over time
• Retrieval- the process of getting information out
of the memory storage *
Memory
• Unlike computers that must process information
sequentially, our brains can function on a dualtrack
• Our brains can process many things
simultaneously by means of parallel processing
– The processing of many aspects of a problem
simultaneously
– The brain’s natural mode of information processing for
many functions *
Memory
• Sensory memory- the immediate very brief
recording of sensory information in the memory
system
• Short-term memory- activated memory that
holds a few items briefly, such as seven digits of a
phone number while dialing, before the
information is stored or forgotten
• Long-term memory- the relatively permanent and
limitless storehouse of the memory system
– Includes knowledge, skills, and experiences *
Memory
• Atkinson and Shiffrin developed a model for
memory that says things enter your sensory
memory first, then it enters your short term,
and lastly it is stored in your long term
memory
• Recent research shows that your short term
memory is not just a temporary shelf for
holding incoming information as stated by
Atkinson and Shiffrin *
Memory
• It is actually an active desktop where your brain
process information, making sense of new input and
linking it with long-term memories
• To emphasize the active processing that occurs in the
middle stage, psychologists use the term working
memory
– A new understanding of short-term memory that focuses
on conscious, active processing of incoming auditory and
visual-spatial information, and of information retrieved
from long-term memory
• Right now, you are using your working memory to link
the information you’re reading with your previously
stored information *
Building memories
• Explicit memories- memory of facts and
experiences that one can consciously know
and declare
– Also called declarative memory
• We encode explicit memories through
conscious, effortful processing
– Encoding that requires attention and conscious
effort *
Building memories
• Other information skips the conscious encoding
track and goes directly into storage
• Automatic processing- unconscious encoding of
incidental information, such as space, time, and
frequency, and of well learned information, such
as word meanings
• Automatic processing produces implicit
memories
– Retention independent of conscious recollection
– Also called nondeclarative memory *
Building memories
• Our implicit memory includes procedural
memory for automatic skills like how to ride a
bike
• Our implicit memory also includes classically
conditioned associations among stimuli
• Without conscious effort we automatically
process information about space, time, and
frequency *
Building memories
• Space- while studying you often encode the place on a
page or in your notebook where certain material
appears; later when needing to retrieve the
information you may visualize where it was on the
page
• Time- while going about your day, you unintentionally
note the sequence of its events; later in the day if you
realize you lost something, you may retrace your steps
to try and find it
• Frequency- you effortlessly keep track of how many
times things happen, as when you suddenly realize this
is the third time you have run into someone today *
Building memories
• Because we have a two track mind, we can
use one track to focus on automatic, routine
things, and use the other to focus on
conscious, effortful processing
• When you see words in your native language
on the side of a truck, you automatically read
them and retrieve their meaning
• Learning to read was not automatic *
Building memories
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• At first, reading this takes effort, but with
practice you can start to perform the task
almost automatically
• We often must use much effort to learn new
tasks that we will eventually be able to do
automatically *
Building memories
• Sensory memory feeds our active working
memory, recording momentary images of scenes
or echoes of sounds
• George Sperling’s studies of sensory memory
demonstrated iconic memory
– A momentary sensory memory of visual stimuli
– A photographic or picture image memory lasting no
more than a few tenths of a second
– Our visual screen clears quickly, as new images are
superimposed over old ones *
Building memories
• We also have an impeccable, though fleeting,
memory for auditory stimuli
• Echoic memory- a momentary sensory memory
of auditory stimuli
– If attention is elsewhere, sounds and words can still
be recalled within 3 or 4 seconds
• When not paying attention in class and the
teacher asks what she just said, you can recover
the last few words from your mind’s echo
chamber *
Building memories
• It is proposed that short term memory can hold about
seven information bits
• It is believed we can recall 7 digits, 6 letters, or 5 words
• Working memory capacity varies, depending on age
and other factors
• Young adults have more working memory capacity
than older adults or children
• their ability to multitask is relatively greater because
they can use their mental workspace more efficiently
• No matter your age, you do better and more efficient
work when focused, without distractions, and on one
task at a time *
Building memories
• There are several effortful processing
strategies that can boost our ability to form
new memories
• Chunking- organizing items into familiar,
manageable units; often occurs automatically
• Try remembering 43 individual numbers and
letters
• Is this difficult? See if this helps to accomplish
this *
Building memories
• Chunking usually occurs so naturally that we
take it for granted
• We can remember information best when we
can organize it into personally meaningful
arrangements *
Building memories
• Mnemonics- memory aids, especially those
techniques that use vivid imagery and
organizational devices
• Vivid imagery is used because we are good at
remembering mental pictures
• We more easily remember concrete,
visualizable words than we do abstract words
• Chunking and mnemonics combined can be
great memory aids for unfamiliar material *
Building memories
• In order to remember the colors of the
rainbow in order of wavelength?
• Remember ROY G. BIV
• We often chunk information into a more
familiar form by creating a word from the first
letters of the to-be-remembered items
– called an acronym *
Building memories
• When people develop expertise in an area,
they process information in hierarchies
• Hierarchies are composed of a few broad
concepts divided and subdivided into
narrower concepts and facts
• For example, this section of the chapter tries
to help you organize some of the memory
concepts we have been discussing *
Building memories
• Organizing information into hierarchies helps
us retrieve information efficiently
• Taking class and text notes in outline format
may be helpful- this is a form of hierarchical
organization *
Building memories
• We retain information better when our encoding
is distributed over time
• Spacing effect- the tendency for distributed study
or practice to yield better long term retention
than is achieved through massed study or
practice
• Massed practice or cramming can produce
speedy short term learning and a feeling of
confidence
• Herman Ebbinghaus once said that those that
learn quickly also forget quickly *
Building memories
• Testing effect- enhanced memory after
retrieving, rather than simply rereading,
information
– Also called retrieval practice effect or testenhanced learning
• Spaced study and self-assessment beat
cramming and rereading *
Building memories
• Memory researchers have discovered that we
process verbal information at different levels,
and that depth of processing affects our long
term retention
• Shallow processing- encoding on a basic level
based on the structure or appearance of
words
– May focus on the word’s letters or a word’s sound
*
Building memories
• Deep processing- encoding semantically,
based on the meaning of the words
– Tends to yield the best retention
– The deeper the processing, the better our
retention
• Example on pg. 325 *
Building memories
• If new information is not meaningful or
related to our experience, we have trouble
processing it
• Example on pg. 325
• Asked how well certain adjectives describe
someone else, we often forget them; asked
how well the adjectives describe us, we
remember the words well
• This is called the self-reference effect *
Memory Storage
• Memory requires brain networks
• The network that processes and stores your
explicit memories for facts and episodes includes
your frontal lobes and hippocampus
• The left and right frontal lobes process different
types of memories
• Recalling a password and holding it in working
memory activates the left frontal lobe
• Calling up a visual party scene would more likely
activate the right frontal lobe *
Memory Storage
• Hippocampus- a neural center located in the
limbic system
• It helps process explicit memories for storage
• Damage to this region disrupts recall of
explicit memories
• With left-hippocampus damage, people have
trouble remembering verbal information but
they have no trouble recalling visual designs
and locations *
Memory Storage
• Subregions of the hippocampus serve
different functions
• One region is active as people learn to
associate names with faces
• Another part is active as memory champions
engage in spatial mnemonics
• Memories are not permanently stored in the
hippocampus *
Memory Storage
• The hippocampus seems to serve as a loading
dock where the brain registers and
temporarily holds the elements of a
remembered episode
• Then after a time, the memories are sent
somewhere else for storage
• Sleep supports memory consolidation
• During deep sleep the hippocampus processes
memories for later retrieval *
Memory Storage
• Even if you lose the ability to lay down explicit
memories, you can still develop implicit
memories for skills and conditioned associations
• Example on pg. 331
• The cerebellum plays a key role in forming and
storing implicit memories created by classical
conditioning
• With a damaged cerebellum, a person may not
be able to learn certain conditioned reflexes _
Memory Storage
• The basal ganglia are deep brain structures
involved in motor movement
• They facilitate formation of our procedural
memories for skills
• Our implicit memory system helps explain why
the reactions and skills we learned during infancy
reach far into our future
• The conscious memory for your first three years
of your life are blank though
• This is called infantile amnesia *
Memory Storage
• There are two possible reasons for infantile
amnesia
– We index much of our explicit memory suing
words that nonspeaking children have not learned
– The hippocampus is one of the last brain
structures to mature *
Memory Storage
• Our emotions trigger stress hormones that
influence memory formation
• Stress hormones provoke the amygdala to
initiate a memory trace in the frontal lobes
and basal ganglia and to boost activity in the
brain’s memory forming areas
• Emotional arousal can sear certain events into
the brain, while disrupting memory for neural
events around the same time *
Memory Storage
• Significantly stressful events can form almost
unforgettable memories
• This may be because memory serves to
predict the future and to alert us to potential
dangers
• We often times remember exciting or
shocking events
• Flashbulb memories- a clear memory of an
emotionally significant moment or event *
Memory Storage
• Our flashbulb memories vivid and we are
usually confident in our recollections of them
• As we relive, rehearse, and discuss the
memories over time, we may often combine
misinformation with accurate information to
the memory *
Memory Storage
• Does the formation of memories impact
neural connections?
• It has been seen in experiments that rapidly
stimulating certain memory circuit
connections has increased a person’s
sensitivity for hours or even weeks to come
• The sending neuron now needs less
prompting to release its neurotransmitter, and
more connections exist between neurons *
Memory Storage
• Long-term potentiation- an increase in a cell’s
firing potential after brief, rapid stimulation
– Believed to be a basis for learning and memory
• After long term potentiation has occurred,
passing an electric current through the brain
wont disrupt old memories
• The current will wipe out very recent memories
• A blow to the head can do the same thing
• Football players or boxers usually have no
memory of events immediately before getting
knocked out from a blow to the head *
Memory Storage
• The reason the new memories are lost is that
the working memory did not have time to
consolidate the information into long term
memory *
Retrieval
• There are three measures of retention
• Recall- a measure of memory in which the person
must retrieve information learned earlier, as on a
fill in the blank test
• Recognition- a measure of memory in which the
person need only identify items previously
learned, as on a multiple choice test
• Relearning- a measure of memory that assesses
the amount of time saved when learning material
again *
Retrieval
• Long after you cannot recall most of the
people in your high school graduating class,
you may still be able to recognize their
yearbook pictures from a photographic lineup
and pick their names from a list of names
• Our recognition memory is quick and vast
• Our speed at relearning reveals memory *
Retrieval
• Ebbinghaus studied relearning in his learning
experiments
• His studies showed that the more frequently he
repeated a list of syllables on day 1, the fewer
repetitions he required to relearn the list on day
2
• Additional rehearsal of verbal information
increases retention, especially when practice was
distributed over time
• His studies emphasized the point that we
remember more than we recall *
Retrieval
• Memories are held in storage by a web of
associations, each piece of information
interconnected with others
• When you encode the name of the person sitting
next to you in class, you associate with it other
bits of information about your surroundings,
mood, seating position, and so on
• These bits are called retrieval cues and they help
us to retrieve information later on
• The more retrieval cues you have the easier it is
to bring a memory out of storage *
Retrieval
• The best retrieval cues come from associations
we form at the time we encode a memorysmells, tastes, and sights that can evoke our
memory of the associated person or event
• To call up visual cues when trying to recall
something, we may mentally place ourselves
in the original context *
Retrieval
• Our associations are often activated without our
awareness
• Priming- the activation, often unconsciously, of
particular associations in memory
• If, walking down a hallway, you see a poster of a
missing child, you may then unconsciously be
primed to interpret an ambiguous adult-child
interaction as a possible kidnapping
• Putting yourself back in the context where you
experienced something can prime memory
retrieval *
Retrieval
• What we learn in one psychological state may
be more easily recalled when we are again in
that state
• What people learn when sad they don’t recall
well in any state but instead they recall it
slightly better when sad again
• Emotions that accompany good or bad events
become retrieval cues *
Retrieval
• mood congruent- the tendency to recall
experiences that are consistent with one’s current
good or bad mood
• If you’ve had a bad night your gloomy mood may
bring back other bad times
• This retrieval effect helps explain why our moods
persist
• When happy, we recall happy events and
therefore see the world as a happy place, which
helps prolong our good mood *
Retrieval
• Serial position effect- our tendency to recall
best the last and first items in a list
– The last refers to the recency effect
– The first refers to the primacy effect
• Why do you remember the first so well?
• Why do you remember the last so well?
• Which one are we more likely to remember
even after a delay? *
Forgetting
• For some memory loss is severe and
permanent
• Anterograde amnesia- an inability to form new
memories
– Can recall your past, but you cannot from new
memories
• Retrograde amnesia- an inability to retrieve
information from one’s past *
Forgetting
• Much of what we sense we never notice, and
what we fail to encode we will never
remember
• Age can effect encoding efficiency
• The brain areas that jump into action when
young adults encode new information are less
responsive in older adults
• This slower encoding helps explain age related
memory decline *
Forgetting
• Even after encoding something well, we
sometimes later forget it
• Ebbinghaus developed a forgetting curve
• His curve describes how the course of
forgetting is initially rapid, then levels off with
time
• One explanation for these forgetting curves is
a gradual fading of the physical memory trace
*
Forgetting
• Sometimes forgetting is not memories faded but
memories unretrieved
• We store into long term memory whats
important to us or what we’ve rehearsed
• Sometimes important events defy our attempts
to access them
• Retrieval problems contribute to the occasional
memory failures of older adults, who more
frequently are frustrated by tip of the tongue
forgetting *
Forgetting
• As you collect more and more information, your
long term memory does not get full but it does
get cluttered
• The clutter can interfere with remembering new
or old information
• Proactive interference- the disruptive effect of
prior learning on the recall of new information
– Your well rehearsed facebook password may interfere
with your retrieval of your newly learned twitter
password *
Forgetting
• Retroactive interference- the disruptive effect
of new learning on the recall of old
information
– If someone sings new lyrics to the tune of an old
song, you may have trouble remembering the
original words
• Information presented in the hour before
sleep is protected from retroactive
interference because the opportunity for
interfering events is minimized *
Forgetting
• The hour before sleep is a good time to
commit information to memory
• The information presented in the seconds just
before sleep is seldom remembered
• Sometimes previously learned
information(Latin) facilitates our learning of
new information(French)
– Called positive transfer *
Forgetting
• Memories often fail us because they are merely
unreliable, self-serving historians
• Sigmund Freud argues that our memory system selfcensors information
• Repress- the basic defense mechanism that banishes
from consciousness anxiety-arousing thoughts,
feelings, and memories
• He believed the repressed thoughts could later be
retrieved through therapy
• Researchers today think repression rarely occurs
• People can forget unwanted neutral information, but
we have a hard time forgetting emotional events *
Memory construction errors
• Memory is not precise
• We infer our past from stored information plus
what we later imagined, expected, saw and heard
• We don’t just retrieve memories, we reweave
them
• The way someone words a question about an
event can impact your memory
• When asked about a car accident you witnessed,
people tended to say the car was going faster
when asked how fast it was going when it crashed
into the other car instead of it bumping into the
other car *
Memory construction errors
• Misinformation effect- incorporating
misleading information into one’s memory of
an event
• So powerful is the misinformation effect that
it can influence later attitudes and behaviors
• Just hearing a vivid retelling of an event can
implant false memories
• Repeatedly imagining nonexistent actions and
events can create false memories *
Memory construction errors
• Among the frailest parts of memory is its source
• We may recognize someone but have no idea
where we have seen the person
• We may dream an event and later be unsure
whether it really happened
• Source amnesia- attributing to the wrong source
an event we have experienced, hear about, read
about, or imagined
– Also called source misattribution *
Memory construction errors
• Misattribution is at the heart of most false
memories
• It can happen when you hear someone tell you a
story about you and you put that story into your
own memory as if you remember it happening it
yourself
• Source amnesia helps explain déjà vu
– That eerie sense that “I’ve experienced this before”
– Cues from the current situation may unconsciously
trigger retrieval of an earlier experience *
Memory construction errors
• The key to déjà vu is familiarity with a stimulus
without a clear idea of where we encountered
it before
• We experience a feeling of familiarity before
we consciously remember details
• When these functions are out of sync, we may
experience a feeling of familiarity without
conscious recall *
Extra ideas to know
• Elaborative rehearsal- a memory technique that involves
thinking about the meaning of the term to be remembered,
as opposed to simply repeating the word to yourself over
and over.
• Maintenance rehearsal- the process of repeatedly
verbalizing or thinking about a piece of information. Your
short term memory is able to hold information about about
20 seconds. However, this time can be increased to about
30 seconds by using Maintenance Rehearsal.
• Semantic memory- a more structured record
of facts, meanings, conceptsand knowledge about the
external world that we have acquired. It refers to general
factual knowledge, shared with others and independent of
personal experience and of thespatial/temporal context in
which it was acquired.
Memory construction errors
• Episodic memory- represents our memory
of experiences and specific events in time in a serial
form, from which we can reconstruct the actual events
that took place at any given point in our lives. It is the
memory of autobiographical events (times, places,
associated emotions and other contextual knowledge)
that can be explicitly stated.
• Procedural memory- a type of long-term memory of
how to perform different actions and skills. Essentially,
it is the memory of how to do certain things. Riding a
bike, tying your shoes and cooking an omelet are all
examples of procedural memories.
Memory construction errors
• Decay- refers to the loss of memory over time
• Eidetic memory- also known as photographic
memory, is the ability to recall with vivid
accuracy things that have been heard, seen or
read. This appears more frequently in children
than in adults, and usually involves visual
images such as artistic illustrations.
• A higher level of ACTH is found to be linked
with flashbulb memories