Memory 3 - Remembering and Forgetting Flashcards
Semantic Memory (Expplicit/ Declarative)
General knowledge of objects, words menaings, facts, people without connetion to specific time and memory
Ways to test - cateogry fluency ( name as many animals as you can in 60 secs or matching tests: which item oes with the one in the centre?)
In Amnesia?
Previously learnt semantic info is preserved but new infomation is imapired
Episodic memory (Explicit/ Declarative)
Memory of events and epxperiences tied to specific time and place
ways to test: free recall (list all words from study phase), cued recall (religious figure on the study list), Recognition (was ‘DOGGY’ on the list?)
Procedual Memory ( Implicit/ Nondeclarative)
Knowledge of how to do thngs;skills
type of test: skill learning: pursuit rotor (tracking); mirror drawing; etc.
Priming (Implicit/ Nondecalarative)
Improvement (speed/accuracy) in processing a stimulus (identification/production/classification) as a result of a prior encounter with the same or a related stimulus
in other words preparation for a task…
Types of test: perceptual identification(name an object obscured by noise)
- words stem/fragment completion (first word that comes to mind)
-Sentance cmpletion (conceptual priming)
Theories of forgetting
Decay - memory fades in time
Interference - memory traces disrupted or replaced by subsequent/ prior learning
- time and interfierence are usually confounded: the longer the delay the more interference
Cockroach study (Minami & Dallenbach, 1946)
Crockroaches though to avoid electric shock
-24 hrs later(allowed to mov freely) 70% forgetting
- BUT Cocroaches immobilised (crawl into dark cone) for 24 hours after learning: only 25% forgetting
Retroactive Interference
Later learning disrupts earlier learning
- memory decreases as the number of intervening trials increases
- Slamecka (1980) read sentances 8 times followed by rest of 4 or 8 trials of equivalent sentances
- Amoun of original sentances forgotten (a number of intervining trials (RI) and initial learning)
Number of intervening trials is critical and not time
Proactive Interference
Prior learning disrupts subsequent learning
- Interference builds up over time
- Underwood (1957): Underwood & Keppel (1962) found that:
-perforamnce declines over successive study-test with similar stimuli
- performance recovers when switch to dissimilar stimuli
When category changed after interference builds up, perfromance jumps
Why does interfereence lead to forgetting?
A cue has a fixed capacity and if asssociated with multple memories hard to retrieve a particular one when the cue is used
Tulving’s (1985) Model
Episodic, semantic and procedureal memories are interactive and defined by levels of conscious awarness
Memory System Degree of conscious awarness
Episodic Autonoetic (self aware)
Semantic Noetic (aware of infor,not origin)
Procedural Anoetic (unaware)
Episodic or ‘Direct’ TEST
Example: recognition memory for previously presented items) intended to measure EPISODIC MEMORY SYSTEM (example: conscious retrieval of past episode)
more complex than one to one mapping
Some episodic tests can be influenced by non-episodic memory systems: you can ‘know’ you’ve recently seen an item without consciously ‘remembering’ the encoding event (find it familiar but don’t recollect it)
The Contemporary Model of LTM Systems
Long term memory - twodepratments Declarative(explicit) and Nondeclarative (implicit)
Declarative includes facts(Semantic) and events (Episodic)
Nondeclaritve includes - procedural skills and habits (procedural) and priming
Simple classical conditioning(emotioanl responses and skeletal musculature), nonassociative learning
What can amnesic patients can do?
-Can learn to perform ‘procedural’ tasks despite complete lack of (episodic) memory for training - (Milner 1962 HM mirror drawing task)
-They show intact perceptual priming - recognition memory tests: perform better under incidental instructions (‘first word that comes to mind’)
What can patients with Rght ocipital lobe resection can do?- Patient MS, Gabrielli et al. 1995
- Showed normal declarative memory (recall, cued recall, recognition, impaired perceptual priming
What about forgetting? Why do we forget?
We seem to not really forget things but just store them deeply (my thought, not a definition)
Is forgetting just a retrieval failure?
- Retrieval is a complex process - many ‘forgotten’ memories can be retrieved under the appropriate context
- Penfield (1958) - stimulating the temporal lobes of patients often elicited trivial ‘memories’
- He argued that the brain retains a permanent record of ALL EXPERIENCES
- 20 to 520 patients had ‘memories’ evoked, and most of these resembled dreams
The Forgetting Curve - Ebbinghaus (1885)
- Learned 169 separate list of nonsence syllabales
- Relearned each list after an interval of 21 mins to 31 days
-Time required to relearn list (to 100%) = measure of forgetting - Information loss is rapid then levels off: A logarithmic function which holds for many different types of learned material
but WHY?
Cue-dependant forgetting - Tulving 1974
- Trace-dependant forgetting (=decay, deteriorration)
- Cue dependent forgetting (Failure of retrieval)
Support to cue-dependant forgetting
- Retrieval performance impoves with cueing
- Retroacvtive interference is WEAKER with cueing
Tulving & Psotka (1971) experiement related to cue-dependant forgetting
Several word lists distrbuted and tested one at a time. At the end of experiment, memory for 1st list tested
Recall declins as the number of lists presented after original learning increaces (retroactive interference)
- RI (retroactive interference) selectively affects free recall (no cue)
- Cued recall/recognition less affected because context reinstated during test
Encoding- Spcificity Principle (Tulving 1979)
- Retrieval success depends on ‘informational overlap’ between encoding (study) and retrieval (test)
- Similar to Transfer-Appropriate processing, but about context rather than processing
- context can be Intrinsic or Extrinsic (Hewitt, 1973)
Transfer-approparite processing (TAP)
There needs to be propert encoding in order for a successfull memory recall
Intrisnic Context
Features that are an integral part of target stimulus (meaning the stimulus has specific characteristics that differentiate it from other stimulus)
Barclay et al (1974) study-test congruence (suotvetstvie) on memory for target words
Study:
a) The man TUNED the PIANO (vs. The man LIFTED the PIANO)
-CUED RECALL
a) “Something melodious” - suotvetstvasht( congruent) -> 4.6 words recalled
b) “Something heavy” (incongruent) -> 1.6 words recalled
-> Recognition cues were better if study and test instrinsic context were similar
Extrinsic Context
Other features present at the time of encoding (time, place, cognitive state) in other words features of the stimulus situation which don’t affect the processing of the stimulus itself
Godden & Baddeleyy (1975) - DIVER STUDY
STUDY:
-List of words
a)on land, or
b) underwater
-TEST: Free Rcall and Recognition
a)on land
b)underwater
-Signifcant test type x encoding context interaction
- memory performance better if study & test extrinsic contexts were matched but only for free recall (recognition has strong intrinsic cues)
Mood Congruency (or the relevance of mood on memory)
Memory improves if moods at study and test match
Mood congruency effect more pronounced in generate condition
Can mood influence memory?
STUDY: Read/ Generate words
A)Happy mood (music)
B) Sad mood (music)
-Generated words better recalled than read words
Repression & Motivated Forgetting
Freud (1901) - People actively(uncosciously) repress negative memories
- Levinger & Clark (1961) - Ss remembver fewer negative associations than neutral ones - evidence for repression?
Parkin et al (1982) repeated study, added 1 week delay. At one week, emotional associations better remembered
Further contrary evidence:
-Memoru of childhood abuse (Williams, 1994) : Those who suffered most abuse were most likely to remember
Contemporary study on Repression & Motivated Forgetting
Mike Anderson’s ‘ Think/ No-Think’ paradigm - simply directing people to forget previously learned associations can reduce later cued recall for those associations
Emily Holmses’ ‘Tetris’ studies: Engaging a visuospatial task immediately after a traumatic event can reduce intrusive memories
Consolidation (Dudai, 2004)
- Physiological basis of memory: glutamate release, protein synthesis, neural growth and rearrangment
- ‘Fixes’ information in long-term memory, strenghtens connections between brain regions over hours, days, months (‘systems’ condoslidation)
Forgetting to sum it all up
- New memories are initially weak and sensitive to disruption before solidifying
- Time consistent with forgetting raates & retrograde amnesia (unconsoldated memories leading up to accident/surgery are lost)
- Consolidation (solidifying, affirming) is selective (not all memories/ connections are consolidated) -> adaptive, efficient (my words: We don’t need to remember everything and perhaps forgetting is one of the best things our memory does in order to preserve our mental state and functioning)
-Much recent work on reconsolidation: Retrieving a memory puts it in a vulnarable state again
