Lecture 2 Flashcards
What are the two explanations for memory traces changing over time?
- Consolidation (integrating new information with old information that already exists in semantic networks)
- Forgetting by remembering (strengthening some information at the expense of other information)
Are memory networks stable?
No. Memory networks are not stable structures and memories change over time.
When we forget something, is the information actually lost? Give 3 reasons.
- Info may be, in fact, “lost” e.g. because the memory trace itself is poor or deteriorating - passive forgetting, a problem with storage
- Info may be inaccessible e.g. due to a lack of retrieval cues or because of interference - passive forgetting, a problem with retrieval
- Info may be inhibited e.g. not enough retrieval cues, or interference - active forgetting
What is the inability to form new memories caused by?
Damage to the hippocampus and other medial temporal lobe (MTL) structures
How do we know most of what we know about this topic?
Individuals who have suffered a trauma, which caused loss of some of the LTM networks e.g. HM
What is the hippocampus critical for?
The acquisition of declarative memories
What is an amnesic?
A person experiencing partial or total loss of their memory. The damage has resulted in the inability to form new memories
Why does damage not harm already formed memories?
Because the hippocampus is not a long-term storage site
What kind of connections does the hippocampus create and how?
Soft connections by binding information together quickly to create higher-level representations
How are hard connections made?
Soft connections are stored/distributed across networks in other cortical areas, becoming integrated with old information
Draw the networks of a soft and hard connection
Soft - linear, Hard - bigger network
Why are there 2 stages to learning and not a single memory system?
Because, this is a very efficient system that allows you to store massive amounts of information. With a single memory system, any time you study new info, this could than interfere and replace what is currently there, if this was the case, you could never acquire anything because everything is interfering with everything else.
What are the two stages of learning?
Stage 1: fast, initial episodic learning, these are vulnerable memories, soft connections, if someone disrupts your learning during this, your learning will be unsuccessful.
Stage 2: slow, long-term storage in neocortex, involving integration with existing knowledge (Integration reduces interference), less vulnerable memories, if we knock out one connection in LTM system, you still have other routes to achieve the same information
Who said consolidation is organisation and why?
Stickgold & Walker (2005), because information that is orgnised or structured, is less vulnerable to forgetting
How quickly does consolidation happen?
It is a slow neocortical learning process that could take hours, days or weeks
What is the temporal gradient in retrograde amnesia?
Where people are unable to remember things that happened just before the injury, presumably because they didn’t undergo consolidation
When does the transfer to neocortex begin? Why?
During “offline” hours, i.e. during sleep, because this is when you process minimal external input due to loss of consciousness - there is reduces interference between new and old information.
What type of learning is sleep particularly helpful for?
Procedural learning, but also declarative learning, due to reactivation of memories
What are the different stages of sleep good for?
Early sleep - important for the consolidation of the hippocampus-dependent declarative learning
Late sleep - important for procedural learning
Walker et al. (2002) compared performance after X hours of being asleep and X hours of being awake. What did they find?
They found that something happens during sleep that facilitated the performance on the task. Participants performed better when they performed the task after a good nights sleep, and performed worse when sleep deprived
Ellenbogen et al. (2006) investigated word pairs on recall. What did they find?
They found that sleeping may protect memories from interference, and if you have a chance to sleep before learning something new, these memories are stored more successfully and then retrieved more successfully.
Clay et al. (2007) investigated whether learning improves over time without practice using a picture-word interference paradigm. What did they find?
They found that it took time to integrate word into LTM store, and that after sleep you have a better declarative memory - it is clear that sleep is influencing learning.
What was Ebbinghaus’ savings method?
The reduction in number of trials necessary to re-learn the material over different retention intervals
What is the forgetting curve?
If you’re tested immediately you have pretty good recall, but very shortly after, you seem to have forgotten most of the information you’ve just studied and there is a slower decline over the longer period
How did Ebbinghaus test himself?
Examined his own ability to learn lists of nonsense syllables, examining his own learning of made-up words. He found he was able to learn some but not others, so re-learned until he knew them. Measured the number of repetitions necessary to relearn the information he forgot over time - led to the plotting of the forgetting function
Did Bahrick (1984)’s findings support that of Ebbinghaus?
Yes. He investigated adults who studied Spanish at school initially after leaving and then 50 years later. Supported the forgetting curve function
How can remembering cause forgetting?
Because retrieval can modify memories as recalling some information changes the record of what you do remember.
Repeated retrieval strengthens a memory trace but also makes related, non-retrieved information less accessible
How do we use inhibition for successful retrieval?
To resolve competition or interference between pieces of information that are active at the same time arising during retrieval
Name a study which investigated retrieval induced forgetting and what did they do?
Anderson et al. (1994). They made people study a bunch of category item pairs e.g. fruit-lemon. Intermixed in this list are items of a different category e.g. metal-iron
During retrieval, only pick the fruit category and you are meant to fill in the word-gap with the information.
What items are inhibited and why?
Items that compete during retrieval. If you study a bunch of fruit varying in predictability, you find that e.g. kiwi is not going to create this effect because they are less popular and so not going to compete
Does actively studying have an affect on the retrieval induced forgetting effect?
Yes. If you study a bunch of word pairs, then study them again, those items will be remembered fine, something about active retrieval attempts that create the effect.
Does the retrieval induced forgetting effect transfer to learning of facts?
Yes. Link to Anderson & Bell. They found that for info you practice, recall is about 60%, for the baseline topics, its about 37%, and for the related topics it is in between. Inhibition from one sentence pair spreads to related topics
Does integration reduce retrieval induced forgetting (RIF)?
Yes. Integrated bits of information are less likely to interfere and compete with one another
How is this linked to eyewitness testimony?
It is possible to inhibit, and therefore remember more poorly, selective details. Information being retrieved has important consequences for what you will remember
What is the paradox of expertise?
Why do experts not become more selective experts and show inhibition? Because they have a highly structures store in their discipline - integration protects against forgetting
