Lecture 17 Flashcards
What does electroencephalogram (EEG) measure?
Brain electrical activity
What is an EGG used for?
- monitor behavioural state
- diagnose epilepsy
- localise brain areas active in different tasks
What does an alpha rhythm reflect?
Being relaxed with eyes closed
What does a beta rhythm mean?
The individual is alert
What are the sleep stages?
awake stage 1 stage 2 stage 3 stage 4 REM
How long does a sleep cycle last?
an hour to two
What happens during REM sleep?
muscles become very relaxed, which allows us to dream. The brain can be active without any output occurring
What generates our basic rhythm?
The suprachiasmatic nucleus in the hypothalamus
What is the role of the reticular activating system?
To monitor intrinsic cycles (through neurons in the hypothalamus) by retinal input. If the neurons in the reticular formation are active, we are aware. if the neurons are exhibiting reduced activity, then we sleep.
What are orexins?
proteins which are released by hypothalamic neurons. Those proteins keep us awake.
What happens in narcolepsy?
There are defective orexin neurons, so people fall asleep unexpectedly
What are the functions of sleep?
- to keep homeostasis in the brain
- memory consolidation
What happens if the body is sleep deprived?
Decreased immunity and psychosis
what are the functions of dreaming?
- memory consolidation during REM sleep
- protects us from waking
What does it mean to be conscious?
To be able to respond immediately to the environment
What are situations where we are unconscious?
- sleep
- coma
- vegetative state
What is Schizophrenia?
It is a disorder of thinking (psychosis)
What are Schizophrenia’s positive symptoms?
- hallucinations
- delusions
- paranoia
What are Schizophrenia’s negative symptoms?
- social withdrawal
- apathy
- catatonia
What is Schizophrenia related to?
The brain dopamine system.
What increases dopamine activity?
amphetamines
What happens during auditory hallucinations in Schizophrenia?
there is activation of areas of the brain that normally process auditory input. the input in the brain is reflected as being external
What are symptoms of depression?
- Persistent sadness,
- apathy,
- feelings of hopelessness,
- loss or gain of appetite,
- sleep disturbance
What is depression thought to be related to?
The brain serotonin system
