Lecture 9 - Basis of Memory Flashcards
Who was Hermann Ebbinghaus?
Herman Hebbinghaus (late 1800s) was one of the first experimental psychologists who studied memory.
An example of the studies he did was looking at how well people were able to memorize nonsense trigrams, e.g. teg, raz, fip.
What were some of the key findings from Ebbinghaus’s work?
Some of the findings from Ebbinghaus’s work are still relevant and studied today.
Some of these include that repetition is more effective when it is spaced out over time than when they all occur at the same time.
List length effects: worse memiry when long lists are studied than shorter lists.
The Forgetting Curve: the shape of how memory declines over time.
What is The Forgetting Curve and who first discovered and proposed this?
The forgetting curve describes the decline in memory over time.
It takes the shape of steep decrease followed by a lessening curve.
Ebbinghaus first publicised this curve.
What is a “law”?
Theories and laws are not the same. Laws describe an invariance or regularity in data, whereas a Theory is an attempt to explain a phenomenon or law.
An example of a law in psychology is the Law of Practice.
What are the Laws of Memory discussed in this lecture?
The Law of Recency.
The Law of Primacy.
The Law of Repetition.
What is the Law of Recency?
The Law of Recency finds that recent information is almost always remembered better than older information. The recency function, however, is is non-linear, with older information decaying at a slower rate than newer information.
What is the Law of Primacy?
The Law of Primacy finds that we remember items at the start of sequences better than other items in the sequence.
Looking at the Law of Primacy, what did Murdoch and Carey (1972) find?
Murdoch and Carey found that in a sequence of items when they changed the modality of information (from auditory to visual and vice versa) the items at the beginning of the new modality were remembered better than items prior to them in the other modality. I.e. primacy effects were seen at each change in modality.
This phenomenon can also be seen when the background in a sequence is changed.
What is the Law of Repetition?
The Law of Repetition states that memories improve with repetition.
In regards to The Law of Repetition, what is the Peterson’s Paradox (1972)?
The Peterson’s paradox refers to the phenomenon that massed repetition yield slightly better performance after a short delay than spaced repetition, however, after a longer delay, spaced repetitions engender much better performance than massed repetition,
How does testing, over repeat studying, improve memory in regards to the Law of Repetition?
Testing improves memory much better than re-learning, in the long term at least.
After a short delay re-learning yields better memory results, however, after a longer delay, testing yields better memory performance.
What are the two reasons we forget?
When we forget something it is either due to an encoding failure or a retrieval failure.
I.e. we either never successfully learned/encoded a memory in the first place.
Or you initially learned some information and encoded a memory, but are now having difficulty retrieving that information/memory.
What are some of the Theories of Retrieval Failure we discussed in the lecture?
Decay Theory.
Interference Theory.
Consolidation Theory.
Inhibition Theory.
What is Decay Theory?
Hint: it is a theory of memory retrieval failure.
Decay Theory simply states that memories fade over time, especially if they are not repeatedly accessed.
In regards to Decay Theory, what is the Brown-Peterson paradigm?
The Brown-Peterson paradigm finds that there is a predictable loss of recently learned trigram over time (subjects count backwards from seven to prevent rehearsal), with almost no memory of the trigram after about 20 seconds.
What is Interference Theory?
Interference Theory states that we forget memories over time because there is increasing competition between what we are trying to remember as we accumulate more information and memories, i.e. there is infcreasing amounts of mental activity.
What was proposed by John McGeogh in 1932 that challenged The Decay theory of memory retrieval failure?
McGeogh claimed that Decay Theory was conceptually flawed because it states a pattern of WHAT happens to memories over time as opposed to WHY this happens.
He then proposed the Interference Theory of memory retrieval failure.
When we learn with associate things together. The more associations we have with a given cue, the more difficulty we have with remembering thins, e.g. our memory was a lot poorer during lockdown as we had many more associations with the one cue - home - which made it difficult to remember the associations.
What are proactive and retroactive interference?
Proactive interference occurs when old associations inhibit the retrieval of newer associations.
Retroactive interference occurs when newer associations prevent the retrieval of older associations.
What are the AB-CD and AB-AC paradigms in regards to memory and how do these paradigms support the Interference Theory and not The Decay Theory ?
The AB-CD paradigm is when participants are present with two lists. On each list there are paired objects, but there are no overlapping pairs, e.g dog-king is on list one, and car-bottle is on list two. The participants are then required to do a memory test where one of the objects in a pair is presented and they need to retrieve the associated object.
The AB-AC paradigm is similar, however, there are overlapping objects between lists, but with different associates. e.g dog-king is on list one and dog-bottle is on list two.
What we find in these tasks is that people have more difficulty correctly retrieving the correct associate in AB-AC paradigms than in AB-CD paradigms.
Interference Theory says that this is the case because there is now increased interence/competition between cues and associations. Decay Theory on the other hand cannnot explain explain this phenomenon.
In 1957 Underwood did a re-analysis of the Brown-Peterson results looking at it from the lens of Interference Theory.
What Underwood found was that there was huge variation in how much material was forgotten over time, with the number of previous experimental trials being a predictor of forgetting.
This is interpreted under The Inference Theory that with more experimental trials there is more interference and proactive interfence that decreasing ability to retrieve memories.
What is the Release from Proactive Interference phenomenon and what was one of the seminal studies looking at this by Wickens, Born and Allen (1963)?
The Release from Proactive Interference phenomenon is seen when memory retrieval improves when the stimuli type changes. It is similar to the primacy effect.
Wickens, Born and Allen (1963) looked at this by doing a memory test similar to the Brown-Peterson tasks, but this time change stimuli from digits to numbers between trials. What they found was that when the stimuli changed memory improved and showed minimal effects of interference on memory retrieval.
Interference Theory explains these results by saying that with the new stimuli type having less interference from prior associations compared to the old stimuli. Theory of Decay does not explain these results.
What is Consolidation Theory?
Consolidation Theory states that if a memory is consolidated then it wont be forgotten, however, if not then it will be. It is based on this idea that when we learn or experience something these memories go through a period of perseveration where the memory is vulnerable to interference and forgetting.
What are the three predictions made by Consolidation Theory?
- Protecting memories during perseveration should enhance consolidation and prevent forgetting - this is seen in practice. When learning is followed by a period of mental inactivity the memory has more time and less interference to consolidate, e.g. participants that sleep after learning exhibit improved memory performance.
- Interrupted perseveration should prevent consolidation and prevent memories from being stored - this is seen in practice with observations of those with retrograde amnesia, such as H.M as well as in rat studies where electroconvulsive shocks to the hippocampas interfers with memory when does soon after learning, but not after 1 hour, i.e. after the memory has been consolidated. This is also seen when the hippocampus is removed.
- If the consolidation is prevented, the memory is not stored and remembering should be impossible - in practice this is actually not seen. Although when interference occurs during perseveration short term memory appears to be affected (with rats) after a longer period of time, say 72 hours as opposed to 1 hour, there is some memory there. This is also seen in the phenomenon of spontaneous recovery during opporant conditioning.
