KHA303 Lecture Notes - Lecture 2: Traumatic Brain Injury, Umbilical Cord, Hemoglobin
3 Jul 2018
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Professor
Cognitive neuroscience week 2:
Psychophysics:
- Experimental psychology
oWhat can we learn about the brain without going in to the brain
oMost traditional way of looking at things
oCognitive psychology
oInformation processing depends on internal representations
Can perform operations on these internal representations
Transformations
Mental rotation
- Common task:
oWhat processes underlie decision making
oWhat stages of processing are involved behaviour
oWhat stages are involved:
Sequentially? Parallel?
Trick is to design experiments well
oReaction times: RTs
Are mostly what is measured
Pushing a button
Manual vs. saccadic RTs
Saccadic: eye movements
Orienting behaviours: attention
Target pops up: eye response time, how long does it
take you to look at that thing
Usually means manual but may be saccadic
- Chronometric: time and accuracy measures
oReaction times: measure of time elapsed between stimulus and
response to the stimulus
Normally measured in ms
oOvert vs. covert
oAccuracy and speed accuracy tradeoffs
Not always a tradeoff
From this, determine whether at sensory end or output end
- Common cognitive tasks:
oSimple detection task:
Press a button as quickly and accuracy as possible when you
see a target stimulus
Push this when it appears
Images vs. words? Top vs. bottom
Half and half; faster depending on word vs. images?
Location of the stimulus
Problems:
Anticipations
Push it before stimulus even appears
Overcome it by doing ‘catch trials’: 20% of the time
nothing appears
find more resources at oneclass.com
find more resources at oneclass.com
Need ways of making sure the subject is doing what
they are supposed to be doing
oLocalization task:
Press z if it is on the left…
This is what he usually uses
For eye movement systems this is easiest
Can be manual
oDiscrimination task: 2AFC
PRESS Z IF IT IS BLUE…
Alternative forced choice: AFC
oLetter matching:
Counterbalancing is important to overcome order effects
Eliminate confounding variables
oMemory comparison:
Sequentially looking
Linear relationships?
- Stroop task:
Neuropsychology:
- Studying the damaged brain
- Postmortem
oEg. Alzheimer’s
oCannot induced lesions in humans so wait until after
- Lesion studies:
oOrigin of lesion
Lesions due to injury or disease
Surgical ablation in animals
Not that long ago this was happening in humans
HM, lobotomized
Seizures: excitatory
Hippocampus has many many connections:
oNot as many layers as neocortex
oImplicit memories, procedural memories, not
skill based memories: these all not effected in
functioning
TMS: artificial lesions
Used to briefly disrupt cognitive processing
Magnetic device put over brain and zap it: prevents this
area from working for a brief moment
oTry to match up where damage is to the specific behaviours and
workings
- Vascular disorders:
oBrain uses 20% of all oxygen we breathe and requires a continuous
supply
oStroke:
Blood vessels damaged severely
oCerebral Palsy
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Experimental psychology: what can we learn about the brain without going in to the brain, most traditional way of looking at things, cognitive psychology, information processing depends on internal representations. Can perform operations on these internal representations. Common task: what processes underlie decision making, what stages of processing are involved behaviour, what stages are involved: Trick is to design experiments well: reaction times: rts. Target pops up: eye response time, how long does it take you to look at that thing. Usually means manual but may be saccadic. Chronometric: time and accuracy measures: reaction times: measure of time elapsed between stimulus and response to the stimulus. Normally measured in ms: overt vs. covert, accuracy and speed accuracy tradeoffs. From this, determine whether at sensory end or output end. Common cognitive tasks: simple detection task: Press a button as quickly and accuracy as possible when you see a target stimulus.
