Unit 1: Background & History, Short Term Memory Flashcards
What is the definition of memory as everything stated by Radvansky in the textbook?
memory is perhaps the most central aspect of human thought
any question about human behavior, cognition, development, and nature requires an understanding of memory
our memory makes us who we are, and it is one of the most intimate parts of ourselves… many feel that the study of human memory is the closest on can get to a systematic study of the human soul
What is the definition of memory as everything stated by Gray?
we owe to memory almost all that we have or are; …our ideas and conceptions are its work, and… our everyday perceptions, thoughts, and movement is derived from this source
memory collects the countless phenomena of our existence into a single whole
every waking moment is full of memories; every thought, every learned response, every act of recognition is based on memory; it can be reasonably be argued that memory is the mind
What are the dictionary definitions of memory?
the mental faculty of retaining and recalling past experience (both true and false, memory is not a video recording)
the act or an instance of remembering; recollection: spent the afternoon lost in memory
all that a person can remember: it hasn’t happened in my memory
something remembered: pleasant childhood memories
the fact being remembered; remembrance: dedicated to their parent’s memory
the period of time covered by the remembrance or recollection of a person or group of persons: within the memory of human kind
biology: persistent modification of behavior resulting from an animal’s experience
What were memory definitions by psychologists?
first, memory is the location, where information is kept… a memory store
second, memory can refer to the thing that holds the content of experience… a memory trace
third, memory is the mental process used to acquire (learn), store, and retrieve (remember) information of all sorts
What are the most basic points of memory definitions?
memory as “container”
memory as “contents”
memory as “process”
encoding: create contents (i.e., memory traces) from experience
storage: rehearse, organize/modify contents
retrieval: accesses content
contents reflect prior experience: there has to be mapping between what we experience and what we believe we experienced
Why is memory research important in psychology?
clinical psychologists
PTSD
changes: development, aging, neuropsychology
contents: clinical, social, cultural
Why is memory research important in outside of psychology?
forensic psychology, eye-witness testimony
politicians, historians
educators
health care workers
law, marketing, history, performing arts, survey methodology, medicine
Who was Hermann Ebbinghaus (1850-1909)?
father of memory research
memory stripped of meaning
inventor of the nonsense syllable (DAX, FOZ, KIR)
discoverer of: learning curve, forgetting function
Who was Fredrick Bartlett (1886-1969)?
impact of prior knowledge and meaning on memory: can seperate past from how we use it in the future
dynamic, function and knowledge are important
reconstruction: memory trace is obstruction from experience, imperfect
schemata: have generic knowledge that will allow them to fill in gaps
use schematic knowledge to reconstruct memories which may change them
What is verbal learning?
emerged from behaviorism
focus: relationship between external variables and human memory performance, forgetting and theories of forgetting
approach: rigorously conducted, list learning (often paired associate) experiments
What is information processing?
core metaphor: human mind as serial computer
to understand/describe computer behavior, specify: hardware, software, available data
What is the cognitive architecture in information processing?
identify components and their general function
characterize components in terms of: capacity, speed, accuracy
What are the components of a simple computer architecture?
input devices/registers
active memory and processing
inactive (but accessible) memory
What are examples of cognitive task analysis in information processing?
what are the mental operations required to perform a task?
how are the operations sequenced?
what information is involved in task?
how is the information accessed?
how is it represented?
how is it altered during the processing?
What are the four components of the modal model of memory?
sensory registers
short-term memory
long-term memory
control processes
What is the function of sensory stores in the modal model of memory?
buffers sensory input for selection and identification
What is the function of short-term memory in the modal model of memory?
temporal storage during processing
What is the function of long-term memory in the modal model of memory?
store declarative and procedural knowledge
declarative: knowing that
procedural: knowing how
What is the function of attention sensory stores in the modal model of memory?
selection and transfer from sensory stores
maintenance of information in STM: if we don’t attend it vanishes
selection and scheduling of tasks: switching from one task to another when performing multiple tasks
Why are there multiple (long-term) memory systems?
long-term memory involves several sub-components
different memory systems for different types of information
What is the declarative memory system?
explicit memory
semantic memory: “permanent”, decontextualized knowledge
episodic memory: “forgettable” event memories
What is the nondeclarative memory system?
implicit memory
procedural memory: knowledge of knowing how to do things
classical conditioning: behaviorism, stimulus and response
priming: idea that encountering info at one point facilities ability to process info at another point
What is the evidence of a STM and LTM distinction?
dual stores: STM & LTM
assumption: mall amount of info held briefly in STM, rehearsal enables and is required for transfer from STM to LTM
support: serial-position-curve phenomena
What is free recall and the serial position curve?
free recall: uncued recall of studied items, order of output unconstrained
manipulate a variety of: encoding factors (e.g., presentation rate), storage factors (e.g., delay)
dependent variable: % recalled as a function of serial position
What are the effects shown on a serial position curve?
primacy: good recall for 1st few items
recency: good recall for last few items on list
What is the modal account of the serial position curve?
recency effect produced by read-out from STM
primacy & “pre-recency” reflect information retrieved from LTM
“transfer” from STM to LTM caused by rehearsal
implications:
primacy & prerecency: increased with rehearsal
recency: unaffected by rehearsal (last few items are sitting in STM bucket)
What was the Rundus (1971) experiment on rehearsal and the serial position curve?
materials: 20-word list, presentation rate was 5s/word
tasks: during study –> overt rehearsal, during test –> free recall
analysis: number of rehearsals for each word (position), percent recall for each word (position)
results: for a given amount of rehearsal, items from the initial serial positions are no better recalled than items from the middle of the list
What is the modal account of the serial position curve?
recency effect produced by read-out from STM
primacy & “pre-recency” reflect information retrieved from LTM
“transfer” from STM to LTM caused by rehearsal
implications: primacy and prerecency increase with rehearsal, recency unaffected by rehearsal
What was the relation between filled delay and recall found by Glanzer & Cunitz (1966)?
manipulate retention interval
assume filled delay replaces contents of STM
results: primacy and prerecency unaffected by delay, recency decreased as delay increased
What was the relation between study-time (rehearsal) and recall found by Glanzer & Cunitz (1966)?
manipulate study-time
assume: study-time and rehearsal are related
results: primacy and prerecency increased with study time, recency unaffected by rehearsal
What was the Baddeley & Warrington (1970) experiment on amnesia and serial position?
H.M. - removal temporal lobe and hippocampus
clobbered explicit memory
yet on immediate test, recency intact
dissociation on immediate test: recency HM = control, pre-recency HM «_space;control
What is dissociation?
evidence for dual store
dissociation: when “a single variable has different affects on two or more measures”
evidence for separate stores, processes, or representation
many variables have dissociative effect on the prerecency & recency portion of serial position curve
What is a digit span task?
materials: random digits, words, etc.
task: serial recall
span defined: list length that produces accurate performance on 50% of trials
span test included in Wechsler Adult Intelligence Scale: but not predictive of IQ
What is capacity defined in terms of the digit span task?
number of digits accurately recalled 50% of the time
What is the standard span in the digit span task?
7 +/- 2 digits
What is the modal model interpretation of capacity in the digit span task?
STM capacity: ~7 chunks
there are 7 slots
1 chunk per slot
What is chunking?
the process of combining information so that it takes up as little as possible of the limited space in STM
chunking increases span
why not a limitless STM?: chunk chunked chunks?
required: chunking scheme, time to apply scheme
What was the Chase & Ericsson (1981) study on the measurement of strategy?
extensive practice: 1 session per day, many weeks
recalled strategy after each trial
What was the initial retrieval structure in the Chase & Ericsson (1981) study on the measurement of strategy?
3 digits –> 3 digits –> rehearsal
What was the chunking shown in the Chase & Ericsson (1981) study on the measurement of strategy?
spontaneously generated mnemonic system
running times important
first mnemonic: “9 0 7” –> “9:07” –> “two-mile time”
What is the hierarchical retrieval structure in the Chase & Ericsson (1981) study on the measurement of strategy?
initial retrieval structure was list of chunks
“supergroups” were chunks made up of other chunks
eventually developed deep hierarchy for retrieval
What is the complex retrieval structure the Chase & Ericsson (1981) study on the measurement of strategy?
method of loci
consider a route you know well and make visual association between location and what you’re trying to remember
sequences comes along for free
How did SF use chunking to increase digit span capacity?
chunk (and elaborated) groups of digits into running times (or historical dates)
devised in used “retrieval structure” to guide: parsing of list in to units, retrieval of items at test
Are running times necessary to get the same digit span task capacity as SF?
only about 1/2 of SF’s mnemonics are running times
others can also improve using either SF’s strategy or their own
critical ingredient in SF’s dramatic success seems to be motivation
can’t measure number of items people retain in STM because people use different strategies in digit span tests
What is the Brown-Peterson Task?
initial attempt to measure duration of STM
procedure: hear sub-span target set 3 letters, count backwards for Xs, recall target
manipulation: length of retention interval
assumption: counting task knocks out rehearsal, measure of the rate of forgetting
What was the main finding of the Brown-Petersen task?
in the absence of rehearsal, sub-span material is forgotten very rapidly from STM
initial interpretation: information rapidly decays from STM
note: with 0-delay, only 80% accuracy
What is the evidence for prospective interference in the Brown-Petersen task?
Keppel & Underwood (1962)
competing predictions:
decay prediction: does delay affect recall? NO
interference prediction: performance decline across trials? YES
conclusion: interference causes forgetting in STM
What is the Sternberg task?
task:
target set: short list of items
probe: a single item
target present –> “old”
target absent –> “new”
What are the three possibilities of STM retrieval?
parallel: simultaneous access to all items
serial self-terminating: consider 1 item at a time, stop when target is a match
serial exhaustive: consider 1 items at a time, check each item on list
What was the study using the Sternberg task in selecting between retrieval models?
materials:
memory set: N letters
probe: target letter
question: is probe in memory set?
manipulations:
set size: 1 to 6 letters
probe type: positive (in memory set), negative (not it set)
What were the results of the study using the Sternberg task in selecting between retrieval models?
RT increased with set size: serial
negative = positive: exhaustive
What are the problems with the serial exhaustive process?
40 ms/comparison seems awfully fast
repetition effect: repeated probe item would get faster performance
serial position effects: if the probe item is at beginning of set it’s faster
What is an alternative approach to Sternberg findings?
assumptions: memory set, the most active portion of LTM memory “searched” in parallel
decision process:
“Yes”: probe-memory similarity > threshold
“No”: deadline – similarity < threshold
set size effects:
encoding: activation/item decreased as set size increased
retrieval: speed of assessment decreased as set size increased
What are the characteristics of STM?
modal model accounts for serial position curve but not long-term recency effects
capacity of STM is limited but also affected by chunking & expertise
n the absence of rehearsal, information is forgotten rapidly, but not on the first trial
serial exhaustive process may be used to scan STM or a parallel process may be used to assess the active contents of LTM
simple “slot model” can’t account for performance of classic STM task
