Jost’s law
if two memories are equally strong at a given time, then the older of the two will be more durable and forgotten less rapidly. Indeed, it is widely believed that new traces are initially vulnerable to disruption until they are gradually stamped into memory.
Consolidation
the time-dependent process by which a new trace is gradually woven into the fabric of memory and by which its components and their interconnections are cemented together
2 types of consolidation that have been proposed
- Synaptic consolidation - the imprint of experience takes time to solidify, because it requires structural changes in the synaptic connections between neurons. (Relies on biological processes that may take hours to days to complete). Until those structural changer occur, the memory is vulnerable
- Systemic consolidation - research implicates a process known as systemic consolidation, which holds that the hippocampus is initially required for memory storage and retrieval but its contribution diminishes over time until the cortex is capable of retrieving the memory on its own. Until the memory becomes independent of the hippocampus, it is vulnerable to disruption. (estimates of the duration of this possess vary, with some evidence suggesting that it may take years in humans)
Vad e trace decay och vilka 2 idéer om vad det innebär finns d?
Trace decay = The gradual weakening of memories resulting from the mere passage of time.
*Many proposals about trace decay have in common the idea that activation decays gradually, even if the item remains stored. Ex: recent exposure to the word HELMET may activate a pre-existing concept. Although activation may fade, the concept remains
- there is another sense of decay, in which a memory’s structural elements degrade, not just activation levels. Thus, associations between features or the features themselves may deteriorate.
- (Finns en del bevis på detta från experiment från djur osv. O vi vet ju om att synaptic pruning o apoptos e en grej)
Hur relaterar neurogenes till incidental forgetting
- En annan orsak t att man glömmer saker kan va neurogenes(i hippocampus). Remodels the hippocampus. Good for learning things, bad for the retention of already stored memories(new neurons
- Några säger att detta förklarar Infantile amnesia(pga mkt neurogenes under den tiden)
- skillnad från decay e att neural connections nt försvinner, men e inaccessible(optogenetik-studie på möss visade att minnen som försvunnit pga infantile amnesia fortfarande är lagrade i hjärnan, men har blivit inaccessible pga neurogenesis-induced forgetting)
En del tänker att the passage of time i sig inte orsakar glömska utan att det är andra faktorer som korrelerar med tid som gör det. Vilka?
Contextual fluctuation: The gradual and persistent drift in incidental context over time,
such that distant memories deviate from the current context more so than newer memories,
thereby diminishing the former’s potency as a retrieval cue for older memories(ex family members change in appearance, making them match less well with the original cue associated to a memory).
Interference: The phenomenon in which the retrieval of a memory can be disrupted by the
presence of related traces in memory
Hur kan man förklara the forgetting curve utifrån teorin om contextual fluctuation som orsak till glömska
one’s incidental context will be most similar to the one that we were in a short while ago, and grows less similar over time
Central feature in common to most situations associated with interference:
inference arises whenever a cue used to access a target becomes associated to additional memories
Competition assumption
The theoretical proposition that the memories associated to a shared retrieval cue automatically impede one another’s retrieval when the cue is presented(olika minnen “fightas”, dom som fightas m target kallas “competitors). Förklaring till interference som dom flesta(?) håller med om
Cue-overload principle
The observed tendency for recall success to decrease as the
number of to-be-remembered items associated to a cue increases.Dvs when a cue gets attached to too many things, its capacity to access any one trace is compromised. Supportar the competition assumption.
Retroactive interference
The tendency for more recently acquired information to impede retrieval of similar older memories.(forgetting caused by encoding new traces into memory in between the initial encoding of the target and when it is tested)
Proactive interference
The tendency for earlier memories to disrupt the retrievability of more recent memories and knowledge
- proactive interference is greatest when the earlier memory and newer memory share a cue
- most severe effects when testing recall rather than recognition
Part-set cuing impairment
When presenting part of a set of items (e.g., a category, a mental list of movies you want to rent) hinders your ability to recall the remaining items in the set
Collaborative inhibition
A phenomenon in which a group of individuals remembers significantly less material collectively than does the combined performance of each group member individually when recalling alone
- might arise in part from the mechanisms that produce part-set cuing inhibition(other ppl generate lots of items while u are listening, the inference this causes may disrupt your retrieval)
Retrieval-induced forgetting
The tendency for the retrieval of some target items from long-term memory to impair the later ability to recall other items related to those targets.
Retrieval practice paradigm
A procedure used to study retrieval-induced forgetting.
- Folk studerar listor med ord från olika kategorier(ex fruits, drinks, trees).
- Sen ombeds dom att repeatedly recall vissa ord från vissa listor (t.ex the cue FRUIT- OR____ o så ska dom säga orange). “retrieval practice”
- sen ska dom säga alla items dom minns från alla kategorier
- obv kmr dom ihåg dom dom övat på bäst. Men d som e intressant e att dom e sämre på att komma ihåg icke-övade ord från kategorier där andra ord övas(t.ex banan om dom övat andra frukter i retrieval practice) än icke-övade ord från kategorier som ej övats alls i retrieval practice
Mnemonic convergence
in essence, discussion aligns peoples memories by encouraging remembering, and also retrieval-induced forgetting(socially shared retrieval-induced forgetting), of the same things
Namn på 3 st (teoriserade) inference mechanisms
Associative blocking, associative unlearning, inhibition
Associative blocking
A theoretical process hypothesized to explain interference effects
during retrieval, according to which a cue fails to elicit a target trace because it repeatedly
elicits a stronger competitor, leading people to abandon efforts to retrieve the target
- The core assumption of the blocking hypothesis is the idea that memories compete for access to awareness when their shared cue is provided. The degree of interference should increase as the cue grows more strongly associated with the competitor, exhibiting what anderson et.al refers to as strength dependent competition.
- According to blocking theory, the cues lead the person to accidentally retrieve the stronger associated item(bc it has been practiced more or whatever). Once accidentally retrieved, this item will achieve greater prominence, having been practiced again, making it even more likely to be accidentally retrieved. Cycle continues bc with each accidental retrieval the wrong answer grows stronger
Associative unlearning
The proposition that the associative bond linking a stimulus to a memory trace will be weakened when the trace is retrieved in error when a different trace is sought. Punishment blabla. (Svår att bevisa :S)
Two-factor model of retroactive interference
teori där både associative unlearning and blocking is needed(for retroactive interference ig). Jag fattar verkl nt hur dom 2 är kompatibla men har nt tid att ta reda på det - boken säger att dom e kompatibla så jag får ba acceptera det
What differs the proposal of inhibition as a cause of forgetting from associative unlearning?
- Unlearning säger att kopplingen mellan en cue och en response försvagas. Men inhibition theory säger att det är själva targeten som inhiberas, och att kopplingen håller sig intakt.
- Inhibition är tänkt att va en attentional control process that suppresses the response. Unlearning e en associative learning mechanism.
Vilka egenskaper har retrieval-induced forgetting
- Cue independence: The increasing ease with repetition may indicate that the habit was once distracting has become inhibited, and so no longer demands effort to control
- Retrieval-specificity: The increasing ease with repetition may indicate that the habit was once distracting has become inhibited, and so no longer demands effort to control induced forgetting of unpracticed competitors (e.g., banana), whereas simply studying the intact pairing (fruitorange) does not.
- Strength independence: försöket att retrieve ett trace från minnet, inte the strengthening of practiced items. För retrieval practice som är omöjliga (ex FRUIT-LU___) ger lika mkt forgetting
- Interference dependence: sånt som är mer interfering blockas mer(ex banan), sånt som är
mindre interfering(ex guava) pga inte interfering -> inget behov av inhibition -> ingen blockning - Attention dependence: mindre retrieval-induced forgetting om man e distraherad
Hjärnavbildningsstudier som talar för inhibition theory av retrieval-induced forgetting
- Mkt Aktivitet i hjärnområden som är associerade med kognitiv kontroll(ventrolateral prefrontal cortex and anterior cingulate cortex) när man ska retrieve ngt första gången, minskas med repetition = The increasing ease with repetition may indicate that the habit was once distracting has become inhibited, and so no longer demands effort to control
- Cortical pattern suppression: as ppl retrieve a particular memory, patterns of brain activity that are unique to other memories that compete with it are gradually suppressed, as might be expected if distracting memories were being actively inhibited
