6 - Rhythms in the Brain Flashcards Preview

PSYC3014 - Behavioural & Cognitive Neuroscience > 6 - Rhythms in the Brain > Flashcards

Flashcards in 6 - Rhythms in the Brain Deck (12):

What is a rhythm?

A cyclical process repeats over time


How do you describe rhythmic patterns?

Shape of the waveform
Amplitude (strength)
Frequency (how often pattern repeats)
Phase (lag)


What type of brain rhythms are active during waking and sleeping?

- High frequency, low amplitude indicate waking and alterness, and dreaming
- Low frequency, high amplitude indicate non-dreaming sleep


What is the rhythm that is active during wakeful relaxation?

Alpha (~8Hz), suppressed when eyes are open


What is the synchrony hypothesis?

Neurons responding to the same object synchronise

E.g. firing in motion, ITC (object, category) and V4 (colour) will all fire in one pattern to a dog and another to a woman


What promotes binding in brain rhythms?


Strong gamma-band coherance


What kind of things do rhythmic core functions regulate?

Breathing, heart rate, oxygen and C02 levels


What regulates and monitors carbon dioxide and oxygen?

Medulla oblongata

Dynamically changes HR and respiration to changing conditions


What are the different categories of biorhythms?

Cicannual ~365 days
Infradian >24 hours
Circadian ~24 hours
Ultradian <24 hours


What does the SCN regulate?

Circadian rhythms.

Lesions abolish free-running rhythms.


Describe the circadian rhythm in humans

Runs around 24.2-25 hours.

The SCN runs on a single-cell basis (20,000) with each cell having it's own clock.

The sun resets the clock daily.


How is the biological clock reset by the sun?

Intrinsically reset by photosensitive retinal ganglion cells which project to the SCN