Retention and forgetting Flashcards
What was Craik and Lockhart’s view on memory?
Levels of processing theory - memory viewed as a by-product of perception and attention, which progresses through stages
e.g. when reading a word:
superficial - physical features of letters
intermediate - phonological features
deep - semantic analysis
Suggested that deeper levels of analysis, better memory for the studied material
What experiment tested the levels of processing theory?
Participants shown 60 words, and were then asked questions about the words (analysis of different levels)
Hypothesised that greater processing of a word would be demonstrated as better recall in subsequent memory test - results seemed to confirm this
What happened on the back of the principles of processing levels?
Theories put forwards to explain learning and retention as processes of consolidation and retrieval
What was Donald Hebb’s view?
Cognitive processes as connections between neuronal assemblies, responsible for perception of stimuli
Consolidation view - when a rat is put in a skinner box and presented with various stimuli, connections start to form in an initial trial, becoming stronger as training continues - in first trial cant pay attention to everything but in later trials further connections can be identified and incorporated, developing and strengthening alongside older ones
Connections acquired little by little as time to process info at progressively deeper levels (stimuli and their associations becoming meaningful i.e. semantic processing, such as light and food)
What did Hebb suggest memory storage depends on?
Formation of circuits of interconnected neurons, and for this connection to be established the learning episode needs to be followed by a period of consolidation
Suggested that processing of information continues even after active rehearsal, and remains vulnerable for up to 30mins
If processing is interrupted in some way learning will not occur and memory will be impaired
How did Duncan test Hebb’s prediction regarding interruption of the consolidation process?
Using an Avoidance Training Task - rat performs specific behaviour to avoid something aversive; tone played, followed by shock which can be avoided if rat moves into second chamber
By trial and error association is learned so escape simply when hear tone
In Duncan’s exp, electroconvulsive shock delivered to rat after delays of different lengths to disrupt consolidation process –> poor memory of the learning episode; when delay only 20s, no learning evident at all, memory completely impaired
Appears that consolidation takes place in first hour after learning episode
What do consolidation theories emphasise?
First stages of retention i.e. coding and storage
Imply that poor memory is attributable not to inability to retrieve info nut rather a LEARNING DEFICIT in which info wasn’t acquired properly in the first place through disruption of consolidation
What do other theories of learning and retention emphasise?
Later stages i.e. retrieval theories
Suggest that formation of memory is instantaneous and once formed can remain permanently intact
Forgetting attributable to difficulties retrieving these memories from LTM i.e. in avoidance task, rat has learned to escape but ECS has disrupted retrieval of this memory
Retrieving particular memories becomes more likely in presence of stimuli present during acquisition stage - contextual cues from original learning environment should facilitate retrieval from LTM
How can the importance of contextual cues be demonstrated?
Following avoidance training, animals tested in same/different contexts
Changes could be physical, time, or even internal e.g. influence of drug
Those in different context took about 10s to escape - this was the length of the tone, meaning they actually received the shock i.e. they didn’t escape based on any retrieved memory of learning
What do Decay theories of forgetting suggest?
Builds on consolidation and view of learning as being gradual strengthening of associative links - suggests that, over a retention interval, weakening of these links results in less accurate memories
Poor memory due to decay of memory trace due to passage of time
How did Jenkins and Dallenbach test the decay theory of forgetting?
2 participants learned lists of nonsense syllables and were tested after several retention intervals spent either awake or sleeping
Hypothesised that similar intervals should produce similar forgetting in both but actually found that as retention intervals get larger the larger the difference between sleeping and waking - after 8hrs, those awake could remember nothing while sleepers recalled about 50% of the material
Suggests that time isnt the important factor, but rather activities occurring during retention interval - information acquired interferes with memory of studied words, which happens far more when awake
What two factors determine extent of interference?
Amount of interfering info
Similarity of interfering and target information
What are the 2 different types of interference?
PROACTIVE - when previously learned info interferes with newly learned info; interference should be greater if a lot of similar info has been previously learned
RETROACTIVE - when exposure to new info AFTER target info interferes with learning - similarity is a critical factor, so if info is more different interference will be less profound
How did McGeoch and MacDonald test the theory of retroactive interference?
Participants required to learn list of adjectives
Control group had waiting interval in phase 2 while exp groups asked to either learn second list of different adjectives or list of synonyms of first list (highly related words)
Group on synonyms had worst recall, clearly indicating that similarity of material has a large effect on retention of information
