Memory

MEMORY

Why are some better at remembering?
Is it skill? Hereditary?
Why is it easier to remember sports statistics rather than exam answers?
How accurate is eyewitness testimony?

EBBINGHAUS

German psychologist was one of first to investigate memory
he memorized 13 nonsense syllables; after varying lengths of time he tried to relearn them
the longer he waited, the longer it took to relearn (most info lost in first few hours)
implications for study-review important-meaningful is more memorable

Most of current scientific work on memory has been conducted in framework of "information processing approach" which uses modern computer science and other related fields to provide a frame of reference to understand the process of memory.

Processes in Memory: Encoding, Storage, and Retrieval

Memory requires noticing information then Encoding, Storage and Retrieval
In order to remember we must focus attention as we are bombarded with massive amounts of sensory information.
For storage to take place some physical change in the brain must take place (Consolidation). When information is stored we must later retrieve it. Failure of retrieval could be from any of the three processes.

Encoding	Noticing and transforming information into a form that can be stored in short-term or long term memory
Selective Attention	Focussing on one piece of infarction while placing other information in the background
Storage	The act of maintaining information in memory
Consolidation	The presumed process, believed to involve the hippocampus by which a permanent memory is formed
Retrieval	The act of bringing to mind material that has been stored in memory

THREE MEMORY SYSTEMS:

Atkinson-Shiffrin model of memory says there are 3 interacting systems of memory: Sensory Memory, Short-Term Memory and Long-Term Memory

Sensory Memory	memory system that holds information coming in through the senses for a period ranging from a fraction of a second to several seconds
Short Term Memory (STM)	the second stage of memory which holds about seven (5-9) items for less than 30 seconds without rehearsal; working memory; the mental workspace we use to keep in mind tasks we are thinking about at any given moment
Long-Term Memory (LTM)	the relatively permanent memory system with a virtually unlimited capacity

Sensory Memory: Images, Echoes

holds images for fraction of second, sounds 2 seconds ( movie is a series of stills)
info held long enough to process, can hold vast amount, but only briefly

George SPERLING (1960)
demonstrated how quickly info disappears from visual register
flashed groups of letters organized in 3 rows for a few seconds. Then tone told subjects which row to recall high tone top row, medium tone -middle row, low tone- bottom row
Finding: if he sounded it immediately after flash of letters, subjects could recall 3-4 letters in any of three rows (they had at least 9 of 12 in visual)
if he waited 1 sec all but 4-5 gone

VISUAL AND AUDITORY REGISTERS
What would happen if auditory info faded as fast as visual information? e.g. flash camera picture in darkened room

in split sec visual register takes in vast amount of info
holding image in mind the icon quickly disappears
compare- visual register took in far more than able to retain for few seconds

Visual register

info may disappear even faster-process involved "masking"
info in visual erased in 1/4 sec and replaced by new info
Auditory info fades more slowly than visual
auditory equivalent of icon is echo-lasts several seconds example stress on words in sentence :YOU did it. You DID it.

Short Term Memory:Short, and Small Capacity

Displacement:	event that occurs when short-term memory is holding its maximum and each new item entering short-term memory pushes out an existing item
Rehearsal:	The act of purposely repeating information to maintain it in short-term memory or to transfer it to long-term memory

SHORT TERM MEMORY (STM):

what we are thinking about or aware of at a certain moment (headache, what someone just said)

used to hold conversation, solve problem, remember to complete task

Tasks of STM
1. to store briefly
2. to work on that info

Capacity of Short Term Memory

to study we shut out world
golfer putting needs silence
only so much info at one time
STM can hold as much info as can be repeated in 1.5-2 seconds (5-10 bits of info)

1. CXM (EASY)
2. MNKTY (EASY)
3. RPJHBZS (HARDER)
4. GBMPVQFJD
5. EGQWJPBRHKA

CHUNKING

to overcome displacement use chunking
organizing groupings-an easily remembered unit-a name, acronym,
number 52973125 : 52 97 31 25
106619451812: 1066 1945 1812

tree song hat sparrow box lilac cat-cluster into sentences to remember
original thinking is that usually can hold 7+/-2 -but number of items not all important
---->it's what can be remembered in 2 seconds

STM performs more than one task at time

ENCODING IN SHORT TERM MEMORY

1.PHONETICALLY -strings of letters/numbers are stored phonetically -in experiments people usually mix up things that are similar sound alike or spoken alike e.g.- man mat mad cap more difficult than pit day cow bar

2. VISUAL MAP -capacity for visual encoding in STM exceeds phonological experiment- subjects given verbal description---> match features picture---> match features -visual more efficiently encoded than verbal

RETENTION AND RETRIEVAL-THEORIES
Why do we forget what's in STM?

most evidence for decay theory from "distracter studies"
1959 Peterson/Peterson -participants asked to learn sequence of letters PSQ then given 3 digit # 167 and asked to count backward from 167 by three's 167--164---161 for 18 seconds then asked to recall three letters
findings: rapid decline in ability to recall PSQ Interference
info is mixed up with old- most often when info resembles old info-losing info provides space

ROTE REHEARSAL
Does repetition work? and how well?
best way to hold info a minute or two is to repeat info
but not efficient for long term-if repeat and then forget you may still recognize it
not so much amount of rehearsal but type of rehearsal

Elaborative Rehearsal requires more "meaningful" processing
without meaning info lost quickly
e.g. when people all introducing themselves often we forget person just ahead of us-we focus on self don't rehearse what other says
remembering DREAMS requires rehearsal

INITIAL PROCESSING
Why does one thing capture attention over others?

we are selective when looking, listening
we choose what to process and give meaning to
we filter out conversation of others "cocktail party phenomenon"
yet we may still know something about others conversations
some unattended to stimuli get through--e.g.- your name

Anne TREISMAN (1960)

she said it is not a single on/off switch but variable control like volume on radio
we can turn down certain parts
we can monitor rest at low volume
can shift if something comes up
sometimes works even if asleep e.g.- baby cries -consciously we attend to very little
we select, and process those signals we recognize and understand
unattended receives some processing -info we attend to enters short-term memory

LONG TERM MEMORY (LTM)
-e.g.. Results on last exam, name of dog, date of birth

Non-declarative Memory:	subsystem within long-term memory consisting of skills acquired through repetitive practice, habits, and simple classically conditioned responses; also called implicit memory
Declarative Memory:	subsystem within long-term memory that stores facts, information and personal life experiences; also called explicit memory
Episodic Memory:	subpart of declarative memory that contains memories of personally experienced events
Semantic Memory:	subpart of declarative memory that stores general knowledge; our mental encyclopedia/dictionary

ENDEL TULVING U of T contended LTM divided into separate memory systems

ENCODING IN LONG TERM MEMORY

Can you Identify caller on phone? know sound of guitar?

these abilities mean some LTM are coded in terms of non verbal images: shapes sounds, smells, tastes -most info stored in terms of "meaning"
very familiar (national anthem Old MCD)verbatim in LTM
but generally we don't have verbatim in LTM
we remember "gist" of story recall either Bob called John or John was called by Bob
We remember MEANING v WORDs

INFO STM--->LTM through elaborative rehearsal
more links and associations---> more likely recalled
we recall semantic better than episodic
episodic gets dated (quickly forget ate hamburger last night unless you are now vegetarian)

IMPLICIT/EXPLICIT MEMORY
Do we recall things not intended?

smell of food can evoke memory
SCHAB experiment 1990 -students given list of adjectives---write opposite -next day recall (in air was smell of chocolate)
chocolate became linked to recall
To recall return to setting -same context

Levels of Processing Model

some researchers (Lockhart, Craik, 1972, 1990) propose a levels-of-processing model
how much we remember depends on how deeply we process the information- when we do something-associate, attach meaning

MEASURING MEMORY

Recall	a measure of retention that requires one to remember material with few or no retrieval cues, as in an essay test
Retrieval	any stimulus or bit of information that aids in the retrieval of particular information from long-term memory
Recognition	a measure of retention that requires one to identify material as familiar, or as having been encountered before

STORAGE AND RETRIEVAL IN LTM

info in STM is lost in less than 20 sec unless rehearsed
under proper circumstances we can recall astonishing amount of info from
LTM
e.g.- adults 40 years after high school could recognize 75% of class names
-not all is remembered when we need it.

CAUSES OF FORGETTING

TIP OF TONGUE PHENOMENON
* more frequent during stress
* other words similar recalled and interfere
* harder you try harder to find
* best method stop trying to find
* occurs most often with words seldom used -weak links

Encoding Failure	forgetting resulting from material never having been put into long-term memory
Consolidation Failure	any disruption in the consolidation process that prevents a permanent memory from forming
Retrograde Amnesia	a loss of memory for events occurring during a period of time preceding a brain trauma that caused a loss of consciousness
Decay Theory	a theory of forgetting that holds that the memory trace, if not used, disappears with the passage of time
Interference	the cause of memory loss that occurs when information or associations stored either before or after a given memory hinder our ability to remember it. Proactive Interference- information from before hinders new information Retroactive Interference-New information hinders old information

Interference -often is reason for not recalling info -2 directions

to learn successfully and avoid interference-make new information distinctive

SCHEMATA AND MEMORY

Reconstruction	a memory that is not an exact replica of an event but has been pieced together from a few highlights, with the use of information that may or may not be accurate
Schemas	the integrated frameworks of knowledge and assumptions we have about people, objects and events which affect how we encode and recall information

FREDRIC BARTLETT (1886-1969)

said experience not recorded like a frozen snapshot
we create a memory as an experience based on what happened to us in past
experience emotions from past shape perception of present
this is basis of modern schema theory
schema is like a script that is filled in by present
unconscious mental representations of events, situations, processes stored in memory that lead you to expect experience to be organized in certain ways

e.g. schema for attending classes
if class empty cancel/wrong room

Purpose of schemata:
* framework to fit new information
* helps you to draw inference--stereotype
* to streamline process of retrieving information

People tend to recall "need to know" information

Effects of cues on Retrieval from LTM

more links easier to recall
Reconstructive Memory-eye witness?
we reconstruct memories as time passes
some for personal defence-repress- to fit image

AUTOBIOGRAPHICAL MEMORY

GENERALLY EARLIEST MEMORY OF EVENTS ARE OF THINGS THAT CHANGED OUR LIVES (birth of sibling, death of family member)

extremely difficult to recall events before 2 years of age--infantile amnesia
typically we recall areas of life where our lives were shaped by decisions

SPECIAL TOPICS ON MEMORY
Many believe values and customs of culture have effect on what we remember

certain types of memory are valued in certain cultures and are reinforced
western focus on memorization

FLASHBULB MEMORIES

includes personal events and historic events how are they formed?
"now-print theory" significant event brain captures entire event and prints like a photograph
print recalled from time to time-discussed
why are unimportant parts recalled
the photo -flashbulb memories are not always accurate
event may undergo periodic revision-we add to picture after event

FACTORS AFFECTING RETRIEVAL

Serial Position Effect	the tendency to recall the beginning and ending items better than the middle items
Primacy Effect	the tendency to recall the first items on a list more readily than the middle items
Recency Effect	the tendency to recall the last items on ails more readily than those in the middle
State-Dependent Memory Effect	tendency to recall information better if one is in the same pharmacological or psychological (mood) state as when the information was encoded
Context-dependent Memory	elements of environment get encoded in memory

IMPROVING YOUR MEMORY

1. Develop motivation for remembering-keep interested
2. Practice memory skills-crosswords, puzzles, anagrams scrabble,discuss
3. Be confident about ability to remember-self-doubt leads to anxiety-interfere-relaxation exercise boost ability
4. Minimize distractions-quiet setting
5. Focus on what you want to remember-attention to detail setting emotions
6. Make connections between new material and info in LTM-Mnemonics
7. Use mental imagery-go through rooms of building and leave items in places
8. Use retrieval cues-create routines-put keys in same place-to recall do something unusual
9. Rely on more than memory-notes-calendar- write things immediately

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