Wk4 - Implicit Long-Term Memory Flashcards
Is implicit memory unitary or non-unitary?
Non-unitary (priming, procedural, associative, non-associative)
What is important in implicit memory?
Sensory modality of the information (e.g., visual things will be mediated to a certain degree by visual cortices)
What region is important for implicit learning?
Striatum
Where is the striatum located?
Part of the basal ganglia
What comprises the striatum?
Caudate and putamen
What disorders involve the striatum?
Parkinson’s Disease
OCD
Schizophrenia
If the striatum is damaged what deficits could this result in?
Implicit learning deficits (less activation of the striatum)
What connects the caudate and the putamen?
Anterior limb of the internal capsule
What region is involved in disgust processing?
Insular cortex
What has been found about Schizophrenics during implicit learning tasks?
They have reduced recruitment of left caudate during implicit learning tasks (deficient recruitment of the striatum)
Explain fMRI findings of implicit learning in schizophrenics and controls
There is a greater amount of caudate activation in the healthy controls during implicit learning.
There is lower caudate activation in the schizophrenics. This indicates lowered implicit learning.
What has been found in relation to OCD patients and implicit learning?
OCD patients have striatal dysfunction of the caudate.
During implicit tasks, there is reduced amount of striatal activity.
How have some OCD patients compensated for their striatal dysfunction?
Recruit the hippocampus to use explicit memory strategies.
Increase their hippocampus activity.
How can you tell if someone has been successfully primed?
If they show a behavioural response which has been influenced by something they experienced earlier on
How is priming often tested?
Using word-stem completion tasks.
Participants are given a list of words.
Asked to complete word-stem with the first word that comes to mind. If participants have been primed, they would be expected to complete the word-stem with words from the list.
Explain Squire et al’s. (1992) PET study of stem completion
Subjects studied a list of 15 words and rated how much they liked the words 1-5
4 between-subject conditions in which participants gave varying responses
What were the 4 conditions used in Squire et al’s. (1992) PET study of stem completion?
No response
Baseline
Priming
Memory
What happened in the no response condition?
Participants viewed 20 word stems, none of which could produce the study words. Participants didn’t have to give a response.
What was the purpose of the no response condition?
Get rid of the brain activity related to giving a response / preparing to speak etc.
What happened in the baseline condition?
Participants viewed 20 word stems, none of which could produce study words.
Completed the word stems with the first word that came to mind
What was the point in the baseline condition?
Brain activity with NO implicit memory going on
What happened in the priming condition?
Participants viewed 20 word stems, 10 of which could produce 10 of the study words.
Completed them with the first word that came to mind
What was the purpose of the priming condition?
Brain activity when priming occurs
This was the main experimental condition of interest. Showing priming
What happened in the memory condition?
Participants were shown 20 word stems, 10 of which could produce 10 of the study words.
Instructed to remember the study words which could complete them
What was the purpose of the memory condition?
Shows brain activity for explicit memory
What brain activity was found in the memory condition (explicit memory)?
Activation of the hippocampus and the hippocampal gyrus
Significant increase of blood to the right posterior medial temporal lobe
What brain activity was found for the priming condition (implicit memory)?
Significant decrease of blood to the right occipital cortex
Found some hippocampal activation
What does the finding of decreased blood to the right occipital cortex in implicit memory indicate?
Indicates that sensory modality is important in implicit memory
What enhances explicit memory performance?
Deeper, more semantic encoding and processing of information/study words
What findings support the idea that sensory modality is important in implicit memory?
Squire et al.’s (1992) PET stem-completion study found decreased blood to the right occipital cortex in the implicit memory condition
Study-test modality changes reduce stem-completion priming effects, but explicit memory performance is unaffected
Explain what the term study-test modality means?
If words are studied auditorily and tested visually then this is a change in study-test modality
How do changes in study-test modality affect implicit memory?
Reduces priming effect / reduces implicit memory
How do changes in study-test modality affect explicit memory?
Explicit memory is unaffected
What is important about study-test modality for implicit memory?
There needs to be a consistent modality in order for priming effects/implicit memory
What type of memory depends on sensory modality?
Implicit memory
What type of memory does not depend on sensory modality?
Explicit memory
What do findings of sensory modality tell us about the relationship between implicit and explicit memory?
There is dissociation between implicit and explicit memory.
They are separable types of memory.
What type of memory does depth of processing enhance?
Explicit memory
Does increasing the semantic encoding of information affect priming effects/implicit memory?
No
Priming effects on stem-completion are unaffected by increased semantic encoding of study words, as shown by depth of processing studies
What 3 types of studies provide evidence for the idea that there is dissociation between implicit and explicit memory?
Study-test modality changes
Depth of processing studies
Studies of amnesiacs
What type of brain damage do amnesiacs typically have?
Temporal lobe damage
What type of memory does temporal lobe damage affect?
Explicit memory
What have findings of stem-completion tasks with amnesiac patients shown?
Amnesiacs with temporal lobe damage cannot explicitly remember the words in the task but normal priming effects are shown
Amnesiacs can complete the stem-completion tasks using implicit memory
Does temporal lobe damage in amnesiacs affect implicit memory?
No - temporal lobe damage only effects explicit memory
Is memory modular?
Yes
Is memory mediated by distinct neural substrates?
Yes
What disease did Clive Wearing have?
Amnesia
What brain damage did Clive Wearing have?
Temporal lobe damage, including hippocampi
What did Clive Wearing suffer from?
Suffered from cerebral encephalitis
What type of memory was damaged for Clive Wearing because of his degeneration of temporal lobes?
Explicit memory was damaged
What type of amnesia did Clive Wearing have?
Anterograde amnesia
What does anterograde amnesia mean?
Cannot form new memories
What can Clive Wearing still do, even though he has temporal lobe damage?
Play the piano. He can still carry out tasks which involve implicit memory. He could sight-read music. Music is an ingrained skill which he won’t forget. Playing piano is an automatic skill for him.
What case study supports the idea that memory is modular and has separable aspects/types which have different neurobiological substrates?
Clive Wearing
What is retrograde amnesia?
Inability to remember things that happened before the brain damage
What is Ribot’s law of regression?
The dissolution of memory is inversely related to the recency of the event
If someone has brain damage, they would find it harder to remember things that happened just before the brain damage, but would find it easier to remember things that happened from a very long time ago
What evidence is there for Ribot’s law of regression?
Autobiographical cueing in amnesiacs shows that recall is typically confined to childhood (can only remember things from very long ago. cannot remember things closer to the occurrence of brain damage)
What is a limitation of Ribot’s law of regression?
There is not consistent evidence.
Warrington & Sanders showed that their sample of amnesiacs had severely impaired memory for events across ALL time periods sampled/tested
Why are there difficulties measuring retrograde amnesia?
Depends on personal, autobiographical information
What are 2 autobiographical methods for measuring retrograde amnesia?
Autobiographical cueing procedure
Autobiographical memory interview
What is a more general measure for measuring retrograde amnesia?
Memory for public events
A public events questionnaire
What is a psychological measure for measuring retrograde amnesia?
Boston Remote Memory Battery
Is memory unitary or non-unitary?
Non-unitary
What does non-unitary mean, in terms of memory?
There are observable dissociations between different aspects of memory
Subtypes of memory are separable
What neurobiological evidence is there for the idea that memory is non-unitary?
Specific parts of the brain seem to be important for different types of memory
What brain regions are important for explicit memory?
Temporal lobes
Hippocampi
What brain regions are important for implicit memory?
Sensory association cortices
Striatum
What is a feature of memories stored in temporal lobe neurons?
Have very high conceptual specificity - we can see individuals neurons and networks of neurons that are associated with very specific concepts
What mediates long-term memory?
Synaptic activity leading to physical changes in the brain (e.g., LTP)
