Flashcards in Lecture 14: Memory Deck (26)
What is memory?
*There is a lot more to memory than retrieving facts. *Memory has 3 function:
1. Natural inference system that allows us to store a few facts and derive others as needed.
2. Relate new events prior knowledge in order to understand them.
3. Deliver relevant knowledge when it is needed.
What are the different types of memory?
*Long - term memory
*Explicit memory (Declarative memory) - memory with conscious recall.
*Episodic memory - Events you have experienced.
*Semantic memory - General knowledge. facts.
*Implicit memory (Non - declarative memory) - Memory without conscious recall.
*Procedural memory - motor skills, actions.
What does the basic memory process?
*Encoding - code information and put into memory.
*Storage - Maintenance of information in memory/
*Retrieval - Recovering information from memory and bringing it into consciousness.
What is encoding?
*Implicit information is treated bottom up (data driven)
*Explicit information is treated top down (concept driven)
-information is processed and reinterpreted before storing
-Active role (different for certain autistics).
In what form is information encoded in the short term store?
*Early view was that information in short term memory was held in an acoustic verbal code (speech - like)
*Evidence: Conrad (1654) presented strings of letters visually to participants and recorded what kind of errors they made.
-When Ps incorrectly recalled some of the letters, they were most likely to recall a letter that sounded like the correct one they had seen.
*Evidence: Wickelgren (1995) found that recall was worse when distracter items rhymed with the items to be learned. Again evidence that the code was speech like.
*These studies led researchers to the conclusion that the short term store holds and uses a verbally based code, related to the spoken names of the stimuli.
*This is referred to as the acoustic - articulatory code because either
-- The actual sound - acoustic code / The pronunciation - articulatory code could be important.
*Research has found that the short term store could retain semantic and visual codes too.
What are multi - store models?
*Memory stores form the basic structure.
*Processes such as attention and rehearsal control the flow of information between them. But main emphasis was on structure.
What is the sensory memory?
*Both visual and auditory stores hold more information that we can process.
*We need to attend to certain items in order to r- remember them.
*Two key characteristics:
-Limited capacity - measures of digit span (how many numbers people can recall)
-Fragility of storage:
- Information decays rapidly from the short term storage.
- Interference affects short term store.
What is limited capacity?
*Grouping digits into smaller chunks makes it easier to remember than without.
What is the fragility of storage?
*Brown - Peterson effect
*Participants asked to study sets of 3 letters.
*Participants tried to recall original letters.
*Performance declined with the delay before recall.
*Old information interferes with the ability to learn new material.
*If the task is to remember XCJ, HBR, TSV, then to also remember KRN would be difficult because the older items interfere with your ability to learn new items.
*But if the last item is 164, then the task is easier because it doesn't interfere with what you have already done.
What is the short term memory (STM)?
*The information processing approach sees STM as a short store of information that is later transported into LTM.
*Bradley & Hitch (1974) proposed a different view of STM which focuses on how information is used not just stored.
What problems are there with the storage only model?
*By mid 1970s all sorts of role and functions were being attributed to the short term store, including problem solving comprehension and reasoning.
What evidence is there to show that the 7+/-2 store might now be sufficient?
*Case studies of individuals with specific impairments in different types of short term memory recall.
*An individual who had a digit span of just two items which would suggest that her entire short term memory system was severely impaired/damaged.
*The short term store must consist of something other than a store - there must be other components capable of performing these other tasks.
What is the Working memory?
*Bradley and Hitch (1974) argued in a now classic chapter, that the traditionally defined short term store is simply part of a larger system.
*This larger system they argued, was compromised of three components:
- Executive control system/central executive: supervises and regulates information in working memory. Allocates mental resources to tasks.
-Articulatory rehearsal loop/phonological loop: retention of verbal phonetic information.
-Visuospatial scratchpad: deals with the retention of visual information.
What are the predictions of the Working memory model?
*If 2 tasks make use of the same component, they cannot be successfully performed together.
*If 2 tasks make use of different components, it should be possible to perform them as well as together as separately.
*Listening and doodling make use of separate working memory components - thus there is little competition for global mental resources which essentially increases your cognitive load and reduces performance.
What Neurological evidence is there for the executive control system?
*From people with very specific deficits in certain cognitive abilities; say, the ability to recall sequences of digits like patient PV who had a digit span of only two.
*This suggests that the part of working memory dealing with the recall of digits can be selectively impaired. IF so, this suggests it is a separate component.
What Experimental evidence is there for the executive control system?
*People with very specific cognitive impairments like PV are rare. Therefore, Baddeley and Hitch decided to manufacture their own patients using student volunteers.
*They did this, not by removing the relevant part of their brain, but by functionally disabling it by requiring participants to do a concurrent task that was likely to occupy the limited capacity short term storage system to varying degrees.
*For example, by asking people to do a reasoning task whilst counting backwards from 271 in threes.
What is the Phonological loop?
*Contains 2 parts:
*Phonological store: Holds acoustic or speech based information for about 2 seconds.
*Articulatory control process: Process which produces inner speech we all hear.
What intuitive evidence is there for the Phonological loop?
*The rehearsal of verbal material relies on the property of the phonological store for keeping about 2 seconds of material available. The more material rehearse, the articulatory process tries to get full cycle of the rehearsal in about 2 seconds.
What experimental evidence is there for the Phonological loop?
*Word length effect
-Subjects asked to recall sets of five words in the correct order.
-Their ability to do so was better for short words than for long words.
-Articulatory suppression also eliminated word length effect.
What evidence is there about the irrelevant speech effect for the Phonological loop?
*Finding that irrelevant or unattended speech impairs immediate recall.
*Suggests that spoken material necessarily enters the phonological store.
What evidence is there about the Phonological similarity effect for the Phonological loop?
*Finding that immediate recall is impaired when items are phonological similar.
*Suggests that the similarity reduces the discriminability in phonological store.
What are the effects of the visuospatial sketchpad?
*Responsible for the setting up and maintaining of visuospatial images and is separate from phonological loop.
What evidence is there for the visuospatial sketchpad?
*Participants learned a list of words using either visual imagery or rote rehearsal.
*Task performed either on its own or in the presence of dynamic visual noise or irrelevant foreign language speech.
*Dynamic visual noise interferes when the task involves the visuospatial sketchpad but no the phonological loop.
*Hearing the irrelevant speech interferes when the task uses phonological loop but does not interfere with tasks involving the visuospatial sketchpad.
What is the central executive?
*Bradley (1996) suggests a specific definition:
-switch of retrieval plans.
-Timesharing of dual task studies.
-Selective attention to certain stimuli while ignoring others.
-Temporary activation of long term memory.
What is the distinction between STS and LTS?
*Evidence from studies of organic brain damage?
- Anterograde amnesia: inability to learn anything new.
-Retrograde amnesia: Loss of memory for events prior to injury. Recovery may occur but is not always complete and information just prior to injury may be lost.
-Selective impairment suggests more than one memory system.