KHA303 Lecture Notes - Lecture 8: Neocortex, Angular Gyrus, Sensory Cortex
3 Jul 2018
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Cognitive Neuroscience week 8: Memory
Difference between learning and memory:
- Learning: the process of acquiring the information
- Memory: the outcome of the process
- Three stages:
oEncoding:
Acquisition and consolidation
oStorage:
Permanent representation of the information that was encoded
oRetrieval:
Stored information is retrieved into control awareness
Or performing a motor act
- Different types of memory:
- Sensory:
oBrief and high capacity
oNot aware of this
oWill decay
- Short term/working memory
oLimited capacity
oConsciously aware of it
oTrying to hold the information in conscious working memory
oWill decay if not moved to long term memory
oInterference, replaced
- Long term memory:
oNon-declarative: implicit memory
Procedural memory:
Not explicitly having to think about how to do acts
Perceptual representation system:
Perceptual priming
oCounting, distractor task, letter strings and have
to complete with first word that comes to mind
oPrevious exposure to list
oBenefit from prior experience
Classical conditioning:
oForm of associative learning
oNot under conscious control
oStimulus elicits a response, neutral stimulus
becomes conditioned when repeatedly paired
with stimulus
Non-associative learning
oHabituation
Response to stimuli decreases over time
oSensitization:
Response to stimulus increases over time
Not aware of the process
find more resources at oneclass.com
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Same time course etc. but we are not aware of it but can
demonstrate it
Further breakdown of these
oDeclarative: explicit memory
Episodic memory:
For events
Linked to time and place
Have context
Semantic memory:
For facts
General knowledge: objects, language, etc.
Things we don’t know when we learnt them, not
attached to time and place
oDays to years
oHigh capacity
oNo limit
oConsciously aware of this process
oImpaired acquisition to long term memory:
Anterograde amnesia
Short term memory loss
The anatomy of memory:
- Medial temporal lobe:
oHippocampus
oParahippocampal
oEntorhinal, perirhinal cortices
oFornix:
oMammillary bodies:
Also apart of the thalamus
oAneterior thalamic nuclei:
Parts of the thalamus
oAmygdala:
Will also be discussed
Important for encoding the affective qualities of memory
oSub-cortical areas project to other prefrontal areas
Sensory memory:
- Medical and other researchers
- Mismatch field (MMF)
oKnown in medical research
- MMF is elicited by a rare deviant (high) tone among standard tones (low)
oIndex of echoic memory
oNegative peak at 100ms
- MMF elicited ISIs of up to 9-10 seconds
- Brief trace:
oBriefer in visual when compared to auditory
Short term memory:
- Atkinson and Shiffrin
- If not rehearsed it may decay, or interference/displacement
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- Are the same areas used for STM and LTM
- Cases to answer this come from double dissociations:
oImpaired STM, spared LTM
Damage to left perisylvian cortex
Impaired digit span but could acquire LTM
Removal of tumor in Left angular gyrus
oShow evidence against modal model of memory
If this were the case you would have both damaged or none
Cant have flowing of information through to LTM
Can information be directly encoded from sensory memory
oImpaired LTM, spared STM
HM, Dory
Bilateral removal of medial temporal lobe, and hippocampus
Is this a pure dissociation?
Consensus that STM and LTM:
Supported by same neural networks but are working
differently and activated at different stages
Working memory model: Baddeley
- Maintenance and manipulation:
- Components and their processes:
oNot modal and structural based
- Memory can come from sensory or LTM
- System:
oPhonological loop:
Encoded according to sound
STM task for verbal information, will get confused if the
information sounds the same
Acoustic store
Articulatory loop
Brodmann area 40: left hemisphere network
Left inferior lateral frontal cortex
Aarea 44 involved in rehearsal
oVisuospatial sketch pad:
Visual and spatial code
It is possible to perform this task and a verbal task at the same
time, but cannot perform two task of each at the same time
Interference
Bilateral areas of the parieto-occipital region
In meta-analysis found this
Different to one study that found right is more involved
Right hemisphere lesions may be more involved in spatial, left
hemisphere in visual images
As shown in lesion studies
PET studies:
Letters and locations viewed
Indicate whether a sample letter or location was
previously shown
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Learning: the process of acquiring the information. Permanent representation of the information that was encoded: retrieval: Stored information is retrieved into control awareness. Sensory: brief and high capacity, not aware of this, will decay. Short term/working memory: limited capacity, consciously aware of it, trying to hold the information in conscious working memory, will decay if not moved to long term memory, interference, replaced. Long term memory: non-declarative: implicit memory. Not explicitly having to think about how to do acts. Perceptual priming: counting, distractor task, letter strings and have to complete with first word that comes to mind, previous exposure to list, benefit from prior experience. Classical conditioning: form of associative learning, not under conscious control, stimulus elicits a response, neutral stimulus becomes conditioned when repeatedly paired with stimulus. Response to stimuli decreases over time: sensitization: Same time course etc. but we are not aware of it but can demonstrate it. Further breakdown of these: declarative: explicit memory.
