LAB STUFF

Question 1

With reference to the individual neurons, what causes the rhythmic oscillation of the EEG (α rhythm) when the eyes are closed?

Answer 1

the combined activity of many pyramidal cells where individual currents of neurons summate to produce a detectable field

Question 2

Explain how the EEG exhibits larger oscillations when someone closes their eyes that when their eyes are open?

Answer 2

when someone opens their eyes, the waves become less synchronised because there is lots of input and so there is a larger amplitude

Question 3

With regards to a visual evoked potential, how does a specific stimulus cause a predictable change in the EEG waveform?

Answer 3

VEP is an example of a CEP which is activation of cortical neurons by a specific stimulus evoked by a visual stimulus. Because this activation is coordinated across many neurons, it generates a predictable change in the electrical signal by EEG electrodes. This is a triphasic wave