How are learning and memory interrelated?
- Different kinds of learning lead to different kinds of memory
- Capacity to retrieve from memory (or not) depends on how we learned something
What is learning?
Neuronal/ brain change due to experience
What is memory?
Storage and reactivation of memory
What did Ebbinghaus do?
- Scientific study of learning and memory
- Tested only one subject – himself
§ Nonsense syllables (consonant-vowel-consonant items, e.g., caz, wux)
§ Avoided associations with real words
Explored the rate of learning and forgetting
What is the total time hypothesis about the rate of learning?
The amount learned is a function of the time spent learning (practice)
What was Ebbinghaus’s rate of learning experiment and result?
- Experiment:
- Lists of 16 syllables
- Learned a new list each day – reciting syllables at a constant rate
- 24 hours later he recorded how much more time (number of trials) he needed to relearn the list
- Result:
- Learning linearly related to amount of study
- ‘practice makes perfect
What does the total time hypothesis state in regards to the brain?
- Practice drives brain plasticity
§ Brain undergoes structural changes in response to learning or environmental demands
§ Studies exploring structural changes in the brain due to expertise (long practice) or new learning
What is the expertise and brain plasticity London taxi drivers study?
- Compared brain volume in taxi drivers relative to healthy controls
- The posterior hippocampus of the taxi drivers was consistently larger
The size of the posterior hippocampus significantly correlated with the time they have spent as taxi drivers
What is the study with medical students about brain plasticity?
- Experiment:
- Medical students scanned at three intervals
- Before, during and after intensive exams
- Result:
- Increases in grey matter volume in the parietal cortex (A) and in the posterior hippocampus (B)
- These remained even three months after studying
Shows that after intense study there are significant structural changes that remain in the brain
When practice drives structural plasticity is it permenant?
- Over time, the brain renormalises the volume in the regions enhanced by practice
- Some structural changes (related to learning a task) may be selected and others dropped (expansions normalisation hypothesis)
Will repetition lead to learning?
- Simple repetition with no attempt to organise the material might not lead to learning
- Especially if information is complex and is not perceived as useful
- Memory and attention are very selective – even after extensive practice/ exposure information is not registered if not deemed important
What is distributed practice and what are it’s caveats?
- Distribute learning trials sparsely across a period of time
- Faster improvement rates of learning and less forgetting
- Caveats:
- Distributed practice takes longer (i.e. less actual time but more days) – not always practical or convenient
- Individuals may feel ‘less efficient’
What was the distributed practice experiment and results?
- Experiment:
- List of words (one at a time), some presented once and some twice
- Those presented twice appeared after variable lags (from 0 to 40 intervening words)
- Also varied the duration of the presentation of each word (1.3s, 2.3s, 4.3s)
- Results
- Lowest recall with words only presented once: but the greater the time the words were shown for the greater the recall (total time hypothesis)
- Presenting words twice increased recall in general
- Compared to words repeated twice with no intervening words (lag), adding intervening words leads to better recall later on for all conditions
- Benefits to memory occur despite total study time was the same between 2 word presentations
- Only the spacing differed
What is the lag effect and what is it related to?
- the lag effect is related to distributed practice
- Lag effect = benefit of repeated study increases as the lag between study occasions increases
What is the deficient processing theory of distributed practice?
· Less attention is payed to recently encountered stimuli
After a longer delay stimuli attract more attention
What is the encoding variability theory of distributed practice?
· Multiple encoding instances create richer associations
Variety of ways stimulus has been encoded
What is the study-phase retrieval theory of distributed practice?
· Second presentation is a reminded of the previous occurrence
· This act strengthens memory for the item
· Bigger benefits when memory is not recent (more effortful)
Does evidence from neuroimaging show evidence for the encoding variability hypothesis or the study-phase retrieval hypothesis?
- Encoding variability: Remembered items show different brain activity patterns across repetitions
- Study-phase retrieval: Brain activation patterns are highly similar from repetition to repetition
- Finding
- The study-phase retrieval hypothesis is favoured by the data
What is the testing/ generation effect?
Learn more efficiently when generating the items yourself
What is the experiment to do with the test/ generation effect?
- To showcase the importance of testing they assigned 4 groups to learn Swahili-English word pairs over the course of a week
- Group 1 (ST): word pairs repeatedly studied and tested
- Group 2 (SnTn): after successful recall, the word was not studied or tested further
- Group 3 (STn): After successful recall, the word was not tested (they continued to be studied)
- Group 4 (SnT): After successful recall, the word was not studied (they continued to be tested)
- Results:
- The rate of learning did not differ across the four groups
- The level of retention was the highest for groups 1 and 4 (where testing continued) about 8% recall
- The level of retention was about 4% with no testing
- Conclusion:
The presence of tests had a major effect on what was remembered one week later.
What is the testing effect?
The effect shows that having to retrieve the answer, rather than being presented with, leads to greater retention
Why is feedback when testing important?
- Errors in recall when training may affect later recall unless corrective feedback is provided
The erroneous retrieval may be strengthened in memory
§ Successfully generating items strengthens memory than passive presentation
§ The sooner an item is tested after initial presentation, the more likely it will be recalled and strengthened
What is the spacing effect?
Spaced presentation enhances memory
What is the expanding retrieval method?
Combination of spacing effect and testing effect
