Lecture 5 - Memory Flashcards
What is memory?
Processes involved in retaining, retrieving, and using information about stimuli, images, events, ideas, and skills after the original information is no longer present.
Is memory an active or passive process?
Active any time some past experience has an impact on how you think or behave now or in the future.
Memory is a behaviour of neurons, not a passive storage!
What is sensory memory?
initial stage that holds all incoming information for seconds or fractions of a second
What is short term memory?
holds five to seven items for about 15 to 20 seconds
What is long term memory?
can hold a large amount of information for years or even decades
Describe the modal model of memory.
Atkinson and Shiffrin’s (1968)
Had structural features including sensory, short term and long term memory.
What are control processes?
active processes that can be controlled by the person
Describe Sperling’s study in 1960.
- attempted measuring the capacity and duration of sensory memory
- presented an array of letters flashing quickly on a screen
Whole report method:
- participants asked to report as many as could be seen
- average of 4.5 out of 12 letters (37.5%)
Partial report method:
- participants heard tone that told them which row of letters to report.
- average of 3.3 out of 4 letters (82%)
- participants could report any of the rows
Delayed partial report method:
- presentation of tone delayed for a fraction of a second after the letters were extinguished
- average of 1 out of 4 letters (25%)
- performance decreases rapidly
What was the results of sperlings experiment?
The decrease in performance is due to the rapid decay of iconic memory (=sensory memory in the modal model).
The letters that were reported were moved from sensory memory to short term memory
What is the duration of STM and how is it tested?
15-20 seconds
Tested with recalling letter and digit series tasks
Participants read aloud series of letters and/or digits
recount them backwards
After a set time (decay interval), they recall a part of the series
After 3 seconds, participants performed at 80%
After 18 seconds, participants performed at 10%
What is proactive interference?
previous knowledge interferes with new information
What is retroactive interference?
new information interferes with existing knowledge
What is the capacity of STM and how is it measured?
Digit span task
How many digits a person can remember
Typical result: five to eight items (Magical Number 7 +/- 2)
Last 15 to 20 seconds or less
What is chunking?
- small units can be combined into larger meaningful units
- very effective learning strategy & STM control process
Chunk - a collection of elements strongly associated with one another but weakly associated with elements in other chunks
What is the change detection paradigm?
STM test that prevents chunking strategies via meaningful units Luck & Vogel (1997)
Memory capacity = “Amount of information” rather than number of items
Used colored squares as well as complex objects to prevent (verbal) rehearsal
What is working memory?
a limited capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning
How does WM differ from STM?
STM holds information for a brief period of time
WM stores, processes and manipulates information, and is active during complex cognition.
Related to executive attention
What are the two components of the phonological loop?
Phonological store: Limited capacity for verbal & auditory information; only holds information for few seconds.
Articulatory process: Responsible for rehearsal that keeps information from decaying.
What is the visuospatial sketchpad?
Holds spatial & visual information (visual imagery) in the mind in the absence of a physical visual stimulus
What is the central executive?
Focuses, divides, switches attention.
Acts as the attention controller & accesses long term memory.
Controls suppression of irrelevant information & phonological loop & visuospatial sketchpad.
What is perseveration?
typical behaviour patients with damage in frontal lobe; repeatedly performing the same action or thought even if it is not achieving the desired goal
caused by damage to central executive
How is WM capacity tested?
Tested with reading span task & operation span task (diagnostic tools to assess individual differences in WM)
What are examples of interference that affects the capacity of WM?
Phonological similarity effect: letters or words that sound similar are confused
Articulatory suppression: speaking prevents one from rehearsing items to be remembered
Word length effect:
memory for wordlists is better for short words it takes longer to rehearse long words and to produce them during recall.
What is the episodic buffer?
added when model was revised
backup store that can hold information longer and has greater capacity than phonological loop or visuospatial sketch pad
uses techniques like chunking
communicates with long-term and working memory components
What is WM from a neural perspective?
behaviour of neurons (being active) while controlled attention (executive function) mediates different processes
What does the prefrontal cortex do?
responsible for processing incoming visual and auditory information.
Monkeys without a prefrontal cortex have difficulty holding information in working memory.
What are the different types of LTM?
Explicit (conscious) - episodic and semantic
Implicit (not conscious) - procedural, priming and classical conditioning
What is the serial position curve?
Shows the distinction between short-term and long-term memories
(Murdoch 1962)
Read word list and write down all words remembered.
What is the primacy and recency effect?
Memory is better for words presented at the beginning of the list (primacy effect) and at the end (recency effect).
Describe what happened with patient HM
Surgery removed hippocampus
Retained short-term memory (STM) but unable to transfer info to long-term memory (LTM)
Unable to form new LTMs
What happened to patient KF?
Accident damaged parietal lobe
Impaired STM (reduced digit span) but functional LTM
Able to form and hold new memories
What does info from patient HM and KF tell us?
Highlights the role of hippocampus for encoding episodic information & the parietal lobe for attention & WM
What is episodic memory?
Involves mental time travel
Tied to personal experience; remembering is reliving.
“Self-knowing” (re-experiencing)
E.g. Remembering standing at the Eiffel tower
Partially overlaps with autobiographic memory
What is semantic memory?
Does not involve mental time travel.
General knowledge, facts
“Knowing”
E.g. Knowing Paris is the capital of France.
Often result from episodic memories
