1b. methods in cognitive neuroscience

state the method type, invasiveness, and brain property used for EEG/ERP scans

method - recording

invasiveness - non-invasive

brain property used - electrical

state the method type, invasiveness, and brain property used for single-cell recording

method - recording

invasiveness - invasive (microelectrodes inserted)

brain property used - electrical

state the method type, invasiveness, and brain property used for TMS

method - stimulation (temporarily deactivating areas)

invasiveness - non-invasive

brain property used - electromagnetic

state the method type, invasiveness, and brain property used for MEG

method - recording

invasiveness - non-invasive

brain property used - magnetic

state the method type, invasiveness, and brain property used for PET

method - recording

invasiveness - invasive (radioactive tracer is pumped through veins)

brain property used - hemodynamic

state the method type, invasiveness, and brain property used for fMRI

method - recording

invasiveness - non-invasive

brain property used - hemodynamic

how does single cell recording work

a tiny microelectrode is implanted into an animal’s axon or outside the axon membrane

this records the neural activity from ideally one, but sometimes a population of neurons

what is the 10-20 system

the system of numbers and letters given to EEG electrodes that help map where signals are coming from in the brain

explain how EEG works

electroencephalography

measures electrical activity in the brain

cap with electrodes is placed on a head, each electrode has a number and letter to keep track of which ones are picking up on electrical signals

records the voltage difference between a recording and reference electrode

what do ERPs show us

the fluctuation in voltage when people are exposed to different stimuli

what does rhythmic oscillations in EEG signals tell us

we can look at the different frequency of brain waves (oscillation) i.e. alpha, beta, gamma to tell us what frequencies are involved in what processes

if two areas are oscillating at the same rate, it suggests they are connected in function

how does MEG work

magnetoencephalography

measures magnetic fields from action potentials, which are so so super hard to detect

uses devices called SQUIDs to measure these magnetic fields

what’s the issue with SQUIDs

they are super expensive and need to be kept super cold so they are a pain in the ass

how do MRI - structural and functional - scans work

structural = uses the different magnetic properties of tissues to produce images of the brain

functional = measures temporary changes in the brain (like deoxyhaemoglobin levels) to assess activity in specific locations

how to PET scans work

positron emission tomography

measures blood flow in an area - assuming that higher blood flow equates to activity in the area

radioactive tracers are used because they follow the blood flow and end up in the areas with the highest blood flow - which is then picked up with a scanner

explain cognitive subtraction

used to calculate activation levels

activity measured in a control task is subtracted from the activity measured in the experimental task

explain DTI - diffusion tensor imaging

measures how different brain areas are physically connected together

follows axons because when they join together they make white matter pathways

uses MRI scans to measure these white matter tracts to view the connectivity

explain fNIRS - functional near-infarred spectroscopy

a smaller and cheaper machine than MRI

uses a cap to shine light on the skull and measure the level of reflection

the amount of reflection tells us about activity

haemoglobin and deoxyhaemoglobin are strong absorbers of light

picks up on the same BOLD contrast as fMRI

intracranial electroencephalography (iEEG)

The only method that has high spatial and temporal resolution

records activity from directly inside the brain while people are undergoing neurosurgery