6. LONG TERM MEMORY Flashcards
What is LTM?
- archive of info about past events and knowledge learned
- works closely with STM/ WM
What are some evidence which shows that LTM and STM are separate processes?
- Case studies of amnesiac patients in neuropsychology
- CW and HM vs KF - Serial Position Curve
What are some of these case studies of amnesiac patients in neuropsychology, and what is the relevance of it?
Henry Molaison
- STM: okay
- LTM: not okay
- Anterogradeamnesia: ability to get material from STM but most of LTM is gone
- he went thru temporal lobotomy due to epileptic seizures
- perirhinal, entorhinal cortex and amgydala was removed
- his LT semantic memory and implicit memory is still intact tho
Clive Wearing
- STM: okay
- LTM: not okay
- acquired similar amnesia to HM
- suffered from Simplex Encephalitis
- every waking moment for him is new
- doesnt remember anything at all
- eg. he knows things like hes worked for BBC but there is no memory that comes to mind
KF
- STM: not okay
- LTM: okay
- retrograde amnesia: ability to get material from LTM, but not STM
- suffered damage to parietal lobe from motorbike acci
- suffered poor digit span for STM (2 only)
- but still can form and hold new memories in life (LTM)
Double dissociation present!!
Explain how the Serial Position Curve shows that LTM and STM are separate processes?
SPC:
- created by presenting a list of words to a parti (one aft another)
- aft last word, parti writes down all the words he/she remembers in any order
- the curve plots the % of a grp of parti that recalled each word vs its position in the list
- this indicates that memory is better for words at the beginning of the list and at the end of the list than for words in the middle
Primacy effect:
- partis are more likely to rmb words presented at the beginning of a sentence
- they had time to rehearse the words and transf them to LTM
- these first few words receive 100% of the partis attention
- eg. Rundus tested this
- 20 words at 1 word per 5 secs
- had a twist where got partis to repeat the words out loud during the 5 sec gap
- RESULTS: words presented early were rehearsed more, and more likely to be remember later
Recency effect:
- there is better memory for stimuli presented at the end of a sentence
- this is cause the most recently presented words are still in STM and are easy for partis to rmb
- eg. Glanzer and Cunitz
- partis recalled words 30 sec aft they heard the last word
- this counting prevented rehearsal and allowed time for info to be lost from STM
- RESULTS: hence the delay eliminated the recency effect
BUT, there is debate regarding recency effect as when a short distractor task after entire list is presented, does wipe out the effect, PRESENTING the same distractor after each item in the list brings back the effect
What is the predominant coding method in LTM?
Semantic coding, though info in LTM can be coded visually or by auditory also
Recognition memory- the identification of a stimulus that was encountered earlier
Eg. Sach’s experi
- partis listen to tape recording of a passage
- measured their recognition memory to determine whether they remembered the exact wording of sentences in the passage or general meaning of passage
- RESULTS: many correctly identified sentence 1) as identical and knew sent 2) was changed
- however, a no. of ppl identified sent 3) and 4) as matching in the passage tho wording was different
- these parti remembered the sentence’s meaning but not exact wording
The finding that specific wording is forgotten but general meaning can be remembered for long time has been confirmed in many experis.
What are the general components of LTM?
LTM consists of explicit (conscious) and implicit (non conscious) memory
- Explicit memory
- episodic memory (personal events)
- semantic memory (facts, knowledge) - Implicit memory
- Procedural memory
- priming
- conditioning
What is Explicit/ Declarative Memory?
The conscious recollection of events experienced and facts learned
Episodic memory:
- memory for personal events
- feeling of mental time travel
- the feeling of re-experiencing the event/ reliving the memory
Semantic memory:
- facts and knowledge
- it is possible to have semantic knowledge of a life event without having an episodic memory
- eg. knowing there was a first time you met your friend and where it occurred, but dk the details
Explain and eg. of Double dissociation in Explicit memories.
KC:
- episodic: no
- semantic: yes
- damaged hippocampus
- has semantic memory but it is limited
- asked to rmb 3 words then make a story out of it
- aft 3 mins, when asked to recall he cant rmb
- his semantic is intact but can only rmb general info abt the past
- however, he is able to acquire very limited new semantic info w a lotof trg
Italian woman with encephalitis:
- episodic: yes
- semantic: no
- she can remember times and events spent with a person
- but she cannot remember their names
Hence, there seems to be separate mechanisms for semantic and episodic memory
What are some interactions between Episodic and Semantic memories?
- Episodic memories can be lost, thus leaving only semantic memories
- Semantic memories can be enhanced if associated with episodic memories. this can influence what we experience (episodic) by determining what we attend to
- Autobiographical memory: memory of specific experiences, includes semantic and episodic memories
- Personal semantic memory: semantic memories that have personal significance
What is Familiarity and Recollection, and what concepts are they related to?
Familiarity- the person seems familiar but you cant rmb any details about specific experiences involving the person
- assoc with semantic memory
- as it is not assoc with the circumstances which knowledge was acquired
Recollection: remembering specific experiences related to the person
- assoc with episodic memory
- as it includes details abt what was happening when knowledge was acquired
- plus an awareness of the event as it was experienced in the past
What is the Remember/ Know procedure and what is the relevance of it?
- parti will be presented with a stim they have encountered bef
- asked to respond to it
- ‘remember’ : if the stim is familiar and they also remember the circumstances under which they occurred
- ‘know’ : if the stim seems familiar but they dont remember experiencing it earlier
- ‘dont know’ : if they dont remember the stimulus at all
This procedure is imp as it distinguishes betw episodic components of memory (remember response) and semantic components (know response)
HENCE research typically shows that forgetting increases with longer intervals from original encoding.
What is Implicit/ Non declarative memory and what are its components?
Memory that unconsciously influences behaviour, but somehow you can retrieve this memory. We often do many things without being able to explain how we do them.
- Procedural memory
- Priming
- Conditioning
Explain Procedural memory.
Procedural memory:
- memory for doing things that usually involve learned skills
- sometimes we need guidance to choose the right procedure to activate the skill
- PM performs procedures without being consciously aware of how to do them
- people who cannot form new LTM can still learn new skills
Pursuit Rotor:
- you track a circle moving around a circular path
- ask the subject to keep their mouse on the path button at all times
- few trials
Mirror Tracing:
- you got a star picture
- instead of looking at it directly
- you look through a mirror to draw this orig image
- try to trace it out
Explain Priming and its related concepts.
Priming:
- the presentation of one stimulus affects the performance on that stimulus when presented again
Repetition priming:
- occurs when the test stimulus is the same as or resembled the priming stimulus
- eg. seeing the word bird may cause you to respond to it more quickly than a later presentation of it
- it is called implicit memory as the priming effect can occur even if partis dont rmb the orig presentation of the priming stimuli
Korsakoff’s syndrome:
- result of chronic alcoholism
- due to vitamin B deficiency they do not eat nutritionally
- unable to form new LT episodic memories
- damage is in the thalamic nuclei
- this leads to anterograde amnesia where old memories are intact
- they may encounter probs with encoding new memories
Eg. Graf (1985)
- tested explicit and implicit memory
- they got subjs to read 10 words and rate how much they like them
- then asked to recall either the words (explicitly) or perform a word completion test (implicit)
- they tested 1) amnesiacs with korsakoff
2) normal alcoholics (control)
3) normal amnesiacs (control) - RESULTS: amnesiacs with korsakoffs recalled fewer words than 2 of the control groups
- this shows that they have poor explicit memory assoc w their amnesia
- BUT, on word completion test testing implicit memory, they performed just as well as the other groups
Explain Classical Conditioning and its relation to Implicit LTM.
- when you meet someone familiar but you cant rmb how you know him
- this emotional reaction is an eg. of implicit memory
- in other cases, pairing a neutral stimulus (eg. tone) with a reflexive response (eg. eye blink induced by air puff)