memory
Memory is an active system that:
three process of memory
storage
retrieval
encoding
the sets of mental operations that people perform on sensory information to convert that information into a form that is usable in the brain's storage systems.
holding on to information for some period of time
getting information that is in storage into a form that can be used.
what is memory?
an active system that receives information from the senses, puts that information in a usable form, and organizes it as it stores it away, and than retrieves the information from storage.
▪ Receives information from the senses
▪ Organizes and alters that information as it stores it away
▪ Retrieves the information from storage
models of memory
information- processing model
models of memory that assumes the processing of information for memory storage is similar to the way a computer processes memory in a series of 3 stages.
Model for human thought based on computer
functions
Proposed the three processes (called them “stages”)
retrieval
encoding
storage
Proposed three memory systems
short-term memory (working memory)
long- term memory
sensory memory
very briefly holds sensory information
briefly holds information currently in use
holds information more or less permanently
parallel distributed processing (PDP) model
a model of memory in which memory processes are proposed to take place at the same time over a large network of natural connections.
models of memory that assumes information that is more " deeply processed' or processed according to its meaning rather than just the sound or physical characteristics of the word or words, will be remembered more efficiently and for a longer period of time.
Sensory Memory ( the very first of memory, where raw information from the senses is held for a very brief period of time)
Point at which information enters the nervous
system through the sensory systems
High capacity, brief duration
it has 2 types
iconic
Echoic memory = the brief memory of something a
person has just heard
visual sensory memory, lasting only a fraction of a second
Capacity: everything that can be seen at one time
Duration: less than 1 second
▪ New visual information “masks” old information
Sperling’s Experiments
whole report procedure
partial report procedure
Briefly display array of letters
Once display is gone:
Ask participants to report as many letters as they can
Briefly display array of letters
Once display is gone:
Use a tone to indicate one particular row
Ask participants to report as many letters as they can
from the indicated row
results: participants could only report some of the letters in the displays
it has 2 results
when display presented and then visual mask shown participants struggled to report the letters in the indicated rows
when display presented and then removed participants were able to remove all letters in the indicated rows
Eidetic imagery = the (rare) ability to access a visual
memory for a long period of time
“Long” → 30 seconds or more
Sometimes what people mean by photographic memory
Capacity: limited to what can be heard at any one
moment
Duration: 2 to 4 seconds
Smaller than capacity of iconic memory
Longer than duration of iconic memory
short term memory = memory system in which information is held for brief periods of time while being used
Duration: can be held for up 30 seconds
Capacity: “magic number” 7 ± 2
Sometimes longer through maintenance rehearsal
Selective attention = ability to focus on only one
stimulus from among all sensory input
How some information enters STM while other
information doesn’t
working memory :an active system that
processes the information in STM
Some memory researchers think it’s exactly the
same thing as STM
Some memory researchers think they’re
different systems
Favor term “working memory”
“STM” → simple storage
“Working memory” → active system
STM capacity
George Miller used digit-span test to estimate
capacity of STM
Digit-span test: a series of numbers is read to subjects
who are then asked to recall the numbers in order
Participants were able to recall about 7 items in order
Magic number 7 ±2
Chunking = combining bits of information into
meaningful units (or chunks)
Example: IVC numbers follow format (949) 451-XXXX
Allows for more information to be held in STM
STM Duration
Lasts about 12 to 30 seconds without
rehearsal
Maintenance rehearsal = saying bits of information
to be remembered over and over in one’s head
Tends to be encoded in auditory form
STM is susceptible to interference
Especially likely to happen if amount of information
exceeds capacity
Example: trying to remember all the names of a
bunch of people you just met
Long-Term Memory (LTM)= the memory system into which all the information is placed to be kept more or less permanently
click to edit
Elaborative rehearsal = a method of transferring information from STM into LTM by making that information meaningful in some way
Duration: potentially life-long
Memories may be available but not accessible
Capacity: potentially unlimited
Types of LTM
Nondeclarative (implicit) memory = memory for skills,
procedures, habits, conditioned responses, etc.
Declarative (explicit) memory = memory for
information that is conscious and known
Not conscious memories, but affect conscious behavior
Includes emotional associations, habits, and simple
conditioned reflexes
Memory for facts
Semantic memory: general knowledge
Episodic memory: personal information not readily
available to others
Knowledge of language, information learned in formal education
Daily activities and events
organized in terms of related meanings and concepts
semantic network model
parallel distributed processing model
can explain how information is stored in connected fashion
can be used to explain speed at which different points can be accessed
Types of Amnesia
Retrograde amnesia = loss of memory from the
point of some injury or trauma backwards
▪ Loss of memory for the past
▪ Common plot device in soap operas
Anterograde amnesia = loss of memory from
the point of injury or trauma forward
Inability to form new long-term memories
Usually does NOT affect procedural LTM
Patients HM (Henry Molaison) and Clive Wearing
Tower of Hanoi
it is a puzzle that is solved a series of steps by moving one disk at a time. the goal is to move all of disks from peg A to peg C
Retrieval Cues
Concepts that are related stored physically closer to
each other than to unrelated concepts
Collins & Quillian (1969)
A canary is a bird → faster response
A canary is an animal → slower response
Task: respond “true” or “false” to statements
Retrieval cue = stimulus for remembering
Priming can occur where experience with information or
concepts can improve later performance
encoding specificity= tendency for memory to be
improved if related information available during
encoding is also available during retrieval
Context-dependent learning: physical surroundings
State-dependent learning: physiological state or
psychological state
Example: classroom
example: emotions
Context-Dependent Memory
Participants (SCUBA divers) tried to memorize two lists of words
water lists
land lists
Learned 36 words underwater
Learned 36 words on land
Participants asked to recall as many words as possible from each list
Participants asked to recall as many words as possible from each list
Words from Land List tested
while participant was…
Words from Water List tested
while participant was…
… on land
Mean = 13.5
… underwater
Mean = 8.6
… underwater
Mean = 11.4
… on land
Mean = 8.4
Recall and Recognition
Recognition = ability to match a piece of information or a stimulus to a stored image or fact
Recall = memory retrieval in which the information to be retrieved must be “pulled” from memory with very few external cues
Examples: essays, short answers, and fill-in-the-blanks
Retrieval failure: recall has failed (at least temporarily)
Tip of the tongue (TOT) phenomenon
Examples: multiple choice, matching, and true/false
False positive = error of recognition in which people think that they recognize a stimulus that is not actually in memory
Case of Father Bernard Pagano
Serial Position Effect (information at beginning
and end of a body of information more accurately remembered than information in middle)
Primacy effect = tendency to remember information
at beginning of a body of information better than
what follows
Recency effect = tendency to remember information at end of a body of information better than the information ahead of it
Distorted/False Memories
Memory is a constructive process
Elizabeth Loftus (UCI professor)
NOT like a videotape
Can change every time you retrieve it
Studies memory and eyewitness testimony
Experiment: show videos of traffic accidents
▪ Eyewitness testimony is not always reliable
Different speed estimates depending on question wording
Ask: About how fast were the cars going when they
(contacted/hit/bumped/collided/smashed) each other?
Flashbulb Memories
Automatic encoding = tendency of certain kinds
of information to enter long-term memory with
little or no effortful encoding
Flashbulb memories = memory of an
unexpected event that has strong emotional
associations for person remembering it
Special type of automatic encoding
Examples: JFK assassination, 9/11 attacks,
personal experiences (like graduation)
Can be positive or negative
Reliability of Memory
Constructive processing = memory retrieval process in which memories are “built,” or reconstructed, from information stored during encoding
With each retrieval, memories may be altered, revised, or
influenced by newer information
Hindsight bias = the tendency to falsely believe that
one could have predicted the outcome of an event
Older memories revised to include newer information
“Monday morning quarterbacking”
Misinformation effect = tendency of misleading
information presented after an event to alter the
memories of the event itself
False memory syndrome = creation of inaccurate or false memories through the suggestion of others, often while the person is under hypnosis
Evidence suggests that false memories cannot be
created for just any kind of memory
Memories must at least be plausible
Ebbinghaus
Hermann Ebbinghaus
Memorized list of nonsense syllables and tested his
retrieval at specific points in time
Curve of forgetting = a graph showing a distinct pattern
in which forgetting is very fast within first hour after
learning a list and then tapers off gradually
Distributed practice = spacing one’s study sessions
Produces better retrieval
Massed practice = studying a complete body of
information all at once
Dementia
General term that describes related symptoms/disorders
Alzheimer’s disease
Vascular dementia
▪ Most common type of dementia
▪ Early on: impairs ability to learn new information
▪ Plaques (protein deposits) and tangles (twisted protein fibers)
▪ Later on: symptoms become more sever
▪ Results after stroke (clot that blocks blood flow to the braid)
▪ Sometimes called vascular cognitive impairment
▪ Second most common type of dementia
Reasons We Forget
Encoding failure: failure to process information into
memory (e.g. change blindness)
Memory trace: physical change in the brain that
occurs when a memory is formed
Decay = loss of unattended sensory memory or STM
Disuse = loss of unused LTM over time
Proactive interference: older information prevents or interferes with the retrieval of newer information
Retroactive interference: newer information prevents or interferes with the retrieval of older information
HSAM
Highly superior autobiographical memory
People with HSAM can remember virtually every
detail of their lives
Good and bad aspects of HSAM
Several possible explanations of HSAM
Special type of OCD
Result of practice/training
Studied by James McGaugh at UCI’s CNLM
Back to Loftus
Memory wars
Practice of “recovering” repressed memories
Implanted false memories of abuse
“Imagine you were sexually abused as a child. Who
would have been your abuser?”
Eyewitness testimony in sexual assault trials
Steve Titus
Ronald Cotton
infantile amnesia
the inability to retrieve memories from much before age 3
autobiographical memory
click to edit