1.1 neurophysiology and techniques

Which frequencies does a high-pass filter cut off?

Frequencies below a specified threshold.

Which frequencies does a low-pass filter cut off?

Frequencies above a specified threshold.

What does attenuates mean?

It means to reduce the amplitude or strength of a signal.

What does a notch filter do?

Attenuates specific frequencies.

What does a band pass do?

Allows frequencies within a specified range to pass through while attenuating those outside it.

Oscillatory brain activity serves to?

Bind information, open and close neural windows, and facilitate communication between brain regions.

What does it mean for the brain to bind information?

Ability to integrate different sensory input to form a cohesive perception or understanding of an experience.

What does it mean to open and close neural networks?

The brain's ability to modulate connectivity between neurons, phase-locking oscillations, so signals transmit effectively.

What are phase-locked oscillations?

When two signals are synchronised in frequency and timing, it allows for enhanced communication between neural populations.

Which signalling mechanisms account for communication between neurons?

Changes in firing rate and changes in phase-locking activity.

What do the peaks of neural oscillations represent?

Excitatory phase, neurons are depolarised, primed to fire, and the communication window is open.

What do the troughs of neural oscillations represent?

Inhibitory phase, neurons are hyperpolarised, harder to activate, and the communication window is closed.

From the lowest Hz to the highest Hz, list the order of brain waves?

Delta, Theta, Alpha, Beta, Gamma.

What is Gamma activity associated with?

High-level cognition and binding above 30Hz

What is Beta activity associated with?

Focused cognition, between 12-30Hz

What is Alpha activity associated with?

Relaxed alertness between 8-12Hz.

What is Theta activity associated with?

Light sleep and encoding 4-8Hz

What is Delta activity associated with?

NREM and restorative functions 0.5-4Hz

What is neuromodulation?

The process by which neurotransmitters or other signalling molecules regulate the activity of neurons