Electrophysiological recordings of brain activity Flashcards
What is another name for micro-electrode recordings?
Single-cell recordings
When are micro-electrode recordings performed?
when humans undergo brain surgery
What is typically measured in micro-electrode recordings?
The firing rate or spike rate (the frequency of action potentials)
What did micro-electrode recordings in humans show?
selective responses to a specific item (e.g. face)
What does EPSP stand for?
Excitatory postsynaptic potential
What is a field potential?
Potential measured outside the neuron
Why is EEG not sensitive to action potential/spikes?
the spatial extent of action potentials is too small and the time too short for them to be reflected in the EEG
of the shape of the electrical fields they elicit
Where is EEG most sensitive to activity?
cortical tissue
What can you extract from EEG?
- how rapidly the EEG signal oscillates
- frequency of EEG to inform on sleep behaviour
- associated w particular stimuli and can analyse seperatly (ERP)
What does frequency refer to?
number of oscillations per unit of time
Higher frequency activity in the EEG is associated with greater what?
cortical activity
What did Cruse et al 2011 find?
Conscious awareness in vegetative patients
What is abnormal in epilepsy?
Synchronisation of post-synaptic potentials
How do ERPs find average segments?
Different types of stimuli are separately averaged and then compared.
Show the stimulus many times to identify the noise and the actual response to the stimulus.
The only consistent is the response to the stimulus
When is N400 elicited?
By any anomaly in a sentence.
