State Dependence Flashcards
What is this?
To influence performance, learned information must be remembered
Some memories survive long intervals
Some memories are short-lived
Facts
What is this?
Trace decay theory of forgetting
Interference theory of forgetting
Theories
Hermann Ebbinghaus (1850-1909)
First experimental investigations of memory
Desired to study formation of original associations
Nonsense syllables (CVC)
Sequence of them would not have pre-existing associations
Therefore, serial learning task
Used himself as a participant (n=1)
What is this called?
The forgetting curve
Hermann Ebbinghaus (1850-1909) developed the method of what to remember what he had learned, and calculated how much savings he had a day before?
Method of savings: Ebbinghaus forgetting curve
Forgetting initially rapid
Then levels off
This is known as which type of Forgetting conditioning in rats:
Conditioned suppression of licking procedure
Rat will stop drinking water when cs is presented as they think the shock will come after
Irrespective of US intensity, hardly any forgetting after 60 days
If rat continues to drink, then their fear is low towards anticipated shock
As shock became more intense, it became a larger suppression toward drinking
memory traces can last as long as 60 days post training, they remembered the tone was paired with the shock
Forgetting in rats – excitatory conditioning
Forgetting can be reduced by a?
a reminder
We can jog memories and improve memories
Avoidance learning procedure (CS>shock)
Relatively high latencies show forgetting tested 3 days later
Memory performance improved by a reminder (apparatus and CS exposure) 24 hr or 10 min prior to test
When investigators gave a reminder of fear before testing the rats showed higher fear on the day of the test
This is known as which type of Forgetting conditioning in rats:
Fear conditioning procedures with shock US: B is excitatory CS, X is the trained inhibitor (Hendersen, 1978)
NB different calculation of suppression level
So, in a more complex learning situation, some forgetting seen within 35 days
Forgetting in rats – inhibitory conditioning
Which type of theory is this:
Information storage is reflected by physical changes in the brain, and in the absence of rehearsal these memory traces become weaker with the passage of time
Describes well the forgetting curve
It is simple
Assumes that forgetting is equal to memory erasure
If a trace “disappears” (or weakens), then the memory is not there
Fails to explain the effect of reminders
Trace decay theory
Forgetting can be reduced by a reminder:
Krechevsky maze
Rapid learning seen by decrease in number of errors
- see how many errors the rat makes when entering new compartments
As training progresses, number of errors decreases
=Rapid learning seen by decrease in number of errors.
Forgetting when tested 25 days later
What did findings show when:
Also presented Extra-maze cues
(i.e., context, 10, 30, 90, or 300 secs of exposure to the reminder)?
Found:
Memory performance restored by a reminder of 90 secs prior to test
300 sec too long reminder without reinforcement = extinguishing memories did not show much improvement (optimal amount of exposure to retrieve the memory)
In humans and other animals, retention wanes with the passage of time (and also with the administration of amnesics) and this can be alleviated with a reminder:
Forgotten memories are not gone or erased
Retrieval failure
Attenuated with a reminder
Which theory fails to explain the effect of reminders?
Trace decay theory
Which theory is this:
Interference theory
Other responses may have been learned before or after the target response (proactive and retroactive interference) and this interference should be a function of similarity
Name some of the theoretical implications of experimental observations:
Memories can last a lot longer than you might think if trace decay were the cause of forgetting
The fact that reminders can jog memories suggests that memories can be forgotten without necessarily having decayed
Temporary retrieval problems point to the importance of interference as a cause of forgetting
Associative learning can explain how reminders work
What is the principles of association?
Post learning 2 stimuli, it is the presentation of one of these that will remind the person of the other stimulus
Stimulus A + Stimulus B =====> Thought of B
(varnish) + (staircase to bed) (sad/rejected)
After learning
Stimulus A ============> Thought of B
(varnish) (sad/rejected)
What design is this?
Cross-over design
-better learning when the context was thew same in encoding and retrieval
Varieties of reminder: Environmental context
Dry vs wet
Music
Odours
Children’s toys
While learning, you also encode other stimuli. This is known as?
Encoding specificity
-Encoding in context provides memory triggers
Category names (e.g., animal) for word lists (e.g., cow, rat, etc.)
Effective cues enable the retrieval of items that would not be retrieved under non-cued recall conditions
Context-dependent memory expression:
Name 3 examples
Spatial environment (dry vs underwater)
Odours
Music
More retention in condition with relaxed condition with lavender and retrieval
True for list of words which were freely recalled
so basically, matching conditions gives the best performance
Internal states - Induction of Mood
Hypnotsis
Used hypnosis to induce either happy (H) or sad (S) moods in their participants.
Participants learned 2 lists one following H induction and one following S induction. They were tested on both lists after either H or S induction.
Findings:
89% recalled list 2
better than 43% for list 1
Regardless of which mood, having the same mood facilitated the list learnt under the same state
However, performance which ended on happy was always higher than sad
What is the term used to describe a temporary but relatively sustained and pervasive affective state, often contrasted in psychology and psychiatry with a more specific and short-term emotion ?
Mood
Which type of learning involves retrieval of info regaled by drug induced states?
State-dependent memory
Which type of learning is this?
State-dependent learning
Rats trained to escape from unavoidable shock in a T-maze
Sodium pentobarbital produced ‘dissociated learning’ in rats
Seen when performance of tasks learned in the drug state does not transfer to the non-drug state
But learning can be reactivated if the drug is re-instated
Context fear conditioning preparation (measured freezing)
Chlordiazepoxide (a benzodiazepine) was administered during extinction learning, as it happens during treatment of anxiety
Rats were conditioned and then experienced extinction (or not) drugged.
Rats were tested both sober and with the drug (on separate days)
This is an example of which type of training?
State dependent extinction
Drug alone does not extinguish fear
State-dependent due to intracerebral inactivation
-state induced by intracranial manipulation
Nucleus reuniens (RE) is a midline thalamic nucleus that interconnects the mPFC with the hippocampus
Context fear conditioning in rats
Inactivation (Muscimol) of RE
Train (A) Test (A and B)
SAL SAL
SAL MUS
MUS SAL
MUS MUS
Train in Context A, and tested in Contexts A (target) and B (generalization)
some rats had inactivation while in training some didn’t
Findings showed:
Nucleus reuniens (RE) is where memory sits
(non-alcoholic) subjects can’t remember, when sober, what happened when drunk. May remember when next drunk
marijuana produced a … effect when no (external) cues to recall were available
amphetamine ineffective (but paired associate task!)
amphetamine did result in … (free recall task, drawing geometric shapes)
These are examples of which type of memory studies?
State-dependent memory: Human studies
Classic experiment: Eich et al (1975)
Effect of marijuana by task
Cued recall gives a higher performance outcome compared to …
Free recall
Name varieties of reminders:
Barbiturate
Alcohol
Amphetamine
Marijuana
Antihistamine
Mood
Is State-dependency unreliable?
Overshadowing effects
88% studies showing evidence for state-dependent effects used in which type of tasks but not in which type of tasks?
88% shown in free recall tasks
90% not shown in cued recall or recognition tests
Overshadowing effects of State-dependency:
State-dependent effects are consistent and reproducible only when contextual cues are not?
Not overshadowed by more explicit reminders
(eg. cued or recognition recall).
-Suggests internal state more important cue in the absence of ‘observable’ retrieval cues
Is State-dependency unreliable?
Overshadowing effects
Is State-dependency is present in which type of recall task?
Free recall
Summary
Trace decay theory of forgetting can’t explain recovered memories
This has led some to argue that memory retrieval is important as is memory encoding (i.e., learning).
Experimental studies confirm that we can later remember something which we earlier seem to have forgotten
Learning doesn’t happen in a vacuum: Memories are embedded with cues during encoding which determine later retrieval
This is what context-dependent memory tells us about learning
