Transcript Process by which information is maintained in long

Memory
What is Memory?
• Memory is a system that encodes, stores
and retrieves information
– Process by which information is taken in,
converted to meaningful patterns and then
saved until such time as it is needed
– E.g., expectancies  stored associations
between behaviors and consequences that
drive behavior
The Three Stages of Memory
The three Stages of Memory
• Sensory Memory
• Working Memory
• Long-Term Memory
Sensory Memory
• Real time capture of sensory stimuli
– Iconic memory  visual images
– Echoic memory  sounds
• Function  Scan sensory information; select
information to focus on and filter everything else
out
• Capacity  12 – 16 items
• Duration .25 seconds
Sensory Memory
• Sperling
– Designed a study to examine the capacity of
the sensory store
– Briefly presented a stimulus array; ask
subjects to:
• Report everything you see
• Report on specific information
DJBW
XHGN
TMLP
Report everything you see
XQYW
PLMG
SQTV
Report contents of second row
Working (or Short-Term) Memory
• Mental work station
• Functions:
– Selects information from sensory store on which
to focus attention
– Temporary storage site for new information
– Processes information so it can be transferred
to long-term memory
• Capacity  7 +/- 2
• Duration approx. 20 seconds
Long-term Memory
• Function Permanent storage site
for all types of information
• Capacity  unlimited
• Duration  unlimited
Three Basic Tasks of Memory
• Encoding
• Storage
• Retrieval
Encoding
• Process of transforming, coding, or
sorting information so that it is in a
useable form
– E.g., like a card catalog, encoding
involves cross-referencing information
under multiple categories
Methods of Encoding
• Chunking  putting multiple pieces of
information together into meaningful
groups; helps to expand the capacity of
working memory
– E.g., Can you remember these numbers?
1 4 9 2 1 7 7 6 1 8 1 2
Methods of Encoding
• Rehearsal
– Maintenance rehearsal involves repeating
information over and over
• Good for maintaining in STM but not useful for
transferring to LTM
– Elaborative rehearsal  connecting new
information with knowledge that is already
stored
• Good for transferring information from STM to LTM
Methods of Encoding
• Levels of Processing
– Deeper processing results in better
remembering
• For example: encoding the word Horse
– Visual  (i.e., how it looks) -- It has a capital letter,
and is arranged cvccv.
– Acoustic  Sounds like course
– Semantic  an animal that eats hay that you can
ride.
Storage
• Process by which information is
maintained in long-term memory
• Divisions of LTM
– Procedural  memory for mental
directions or procedures
– Declarative  memory for facts and events
• Episodic  Stores personal information;
memory for events in your life
• Semantic  Basic meanings of words and
concepts
Retrieval
• Process by which information is accessed
from long term memory so that is can be
used or modified by new information
• Depends on how information was encoded
and stored
Factors Affecting Retrieval
• Depth of Processing  retrieval is better
– the more deeply information is processed
– The more connections that have been formed with
existing information
• Retrieval Cues  Stimuli that help to bring a memory to
consciousness
• Encoding specificity  The more closely the retrieval
cues match the cues present at encoding, the more
readily the information will be retrieved
• Mood  biases retrieval of information that is moodcongruent
Retrieval
• Implicit Recall – Memory that was not
deliberately learned or was outside of
conscious awareness
– Priming – process of providing cues that
stimulate retrieval of implicit memories without
awareness of connection between the cue
and the retrieved memory
Retrieval
• Explicit – Memory that has been
processed with awareness and requires
effort and conscious awareness
– Recall  Must produce previously stored
information (Short answer question)
– Recognition  Identify stimulus as having
been presented previously (i.e., multiple
choice)
H.M.
• Removed hippocampus and amygdala on both
sides of brain to control severe epileptic seizures
• Result  severe anterograde amnesia
– Inability to form new memories
– Unable to transfer information from short-term to longterm memories
• Memory deficits are uniquely for declarative but
not procedural memories
Forgetting or Memory Lapses
• Serial Position Effect
– First and last items on a list block retrieval of
information in the middle
• Context – dependent learning
– Memory fails when context at retrieval differs from
context at encoding
• Reconstructive nature of memory
– Take in information, discard details, organize rest in
meaningful patterns
– At retrieval, reconstruct details based on fragments
that are stored