Tools: Neuroimaging Flashcards
Nervous system development
Nervous system develops over the first weeks in da womb
Basic biological processes are largely unaffected by embryo development
Central nervous system can be altered by chemical environments during foetal development
Synaptogenesis
Neurons multiple and grow over the lifetime, but greatest over the first few months
Renewal in puberty
– when we see abnormal behaviours develop/mental illness
Myelination
The fatty tissue that provides axon insulation and speeds up brain processes
Coincides with increased processing speed
EEG / MEG
EEG - measures electrical current
MEG - magnetic field produced by electrical current
– good temporal resolution
Event-related potential - how do we operationalise EEG
An ongoing stream of EEG
Ppts sit in front of a screen and shown different images/videos
Take signals from the time locked to when the event occurred, and average across trials to generate the event related potential
ERPs are positive P or negative N
Amplitudes shift over development
Optically pumped magnometers
Wearable MEG - less resolution but able to measure on different developmental populations who are unable to remain still (e.g. younger children, neuro-divergent populations)
Measuring Haemodynamics - blood flow
When neurons are active they use up energy and oxygen
Need to be replenished after usage so blood flow increases to area roughly 6 seconds after activity
fMRI
Measured the magnetic field that goes through human tissue
As blood oxygen levels move through the field they cause fluctuations which MRI measures
fNIRS
An infrared light that measures blood flow between light sources which travels through brain tissue and is absorbed by blood
Can measure increases or decreases in blood flow
Uniquely advantageous for infants as light penetration is deeper with them
Good spatial resolution of the cortical surface
Basic block design trials with fNIRS
Block specific stimuli together and complete one at a time
Congruent blocks are easy and lead to less activity
Incongruent blocks are difficult and use more activity - leading to increase in blood flow to the area that is active for that task
fMRI of adolescents to hostile faces - Perez-Edgar
Adolescents who were identified as behaviourally inhibited toddlers vs. not
Amygdala was more active while viewing hostile faces in inhibited and when asked to rate their own level of fear
Precise localisation - tells us where something occurs well (spatial)
fNIRS and free play - Hashmi et al. 2020
Blocks of playing alone or with an experimenter with structured games
fNIRS and free play - Hashmi et al. 2020
Blocks of playing alone or with an experimenter with structured games
