Lecture 12 - The Remembering Brain 2 Flashcards
What is the Short Term Memory?
Memory for info currently in mind - limited capacity
What is the Long Term Memory?
Stored memory not consciously accessible - unlimited capacity
What does Baddeley & Hitch (197) Working Memory Model propose?
Separate STM stores
- Central executive
- Phonological loop
- Visuospatial sketchpad
- Episodic buffer
Working memory is an extension of the STM - wider role in cognition
What is the Phonological Loop?
Contains phonological store (verbal) and rehearsal mechanism
The phonological store - left supramarginal gyrus
The rehearsal system - Brodmann’s area 44 (Broca’s area)
What does the digit span task reflect?
Can store 7 + or - 2 item chunks
What is the neural basis of the visuospatial sketchpad?
Regions of inferior temporal cortex
What is articulatory suppression?
Prevention of mentally rehearsing or articulating verbal info
A cognitive task that involves repeating a specific sound or articulatory movement - interferes with verbal working memory
- Disrupts / suppresses inner speech (self talk or rehearsal)
What is the role of the prefrontal cortex in working memory?- Monkey study
Delayed response task measures working memory
- Retain location of unseen food during delay period (working memory)
- Prefrontal lesions affect their ability in performing this task
What is the role of PFC neurons in working memory / associative studies?
Neurons active during the delay period provides a neural correlate for keeping a representation active after triggering stimulus no longer active
Remain active if animal needs the info for upcoming action
If task condition changes, same neurons become responsive to new set of stimuli
What is the role of the prefrontal cortex in working memory for faces?
Working memory relies on the interaction of PFC and other parts of the brain that contain perceptual and long term knowledge relevant to a goal
What does Petrides’ model of working memory assume?
Division of PFC into at leas two separate processes
PFC - maintains activity and relieves info - manipulates and monitors
Patient HM
Inability to make new memories
Cannot transfer new info to LTM
Intact STM
Patient KF
Left parieto-occipital damage
Normal LTM
Small STM (low digit span)
What is the PFC identified as in Baddeley’s working memory model?
The central executive - responsible for maintenance and control of info
What is the role of the PFC and memory encoding?
- Encoding of words / semantic memories = LEFT PFC
- Encoding of spatial info or faces = RIGHT PFC
What is the role of the PFC in subsequent memory for clustered recall?
- Dorsolateral PFC - activation predictive of semantic clustering
- Ventrolateral PFC - activation predictive of recall clustered or non-clustered
What is the role of the PFC and retrieval
Aids organisation, selection and monitoring of processing that happens at retrieval
Activity greatest when retrieval is minimal - free recall - strategic searching
What is free recall?
Minimal cues to aid memory performance
Greater strategic search, organisation, selection and evaluation of retrieved info compared to recognition or cued recall
What is source monitoring?
Related to recall and recollection that stresses the ability to attribute memories for original CONTEXT
What is the role of the PFC in source monitoring?
Places an event in context, requires evaluative processes before we are able to access the original of the memory
- Putting memories in their spatial and temporal context
- May experience remembering (can perform a recognition task) but fail to retrieve the correct source
