EEG- electroencephalogram

• EEG scanners measure electrical activity through electrodes accatched to the scalp
• information is processed in the brain as electrical activity in the form of action potentials or nerve impulses
• small electrical charges are detected by the electrodes and graphed over a period of time, indicating the level of activity. There are four types of EEG patterns- alpha, beta, theta and delta waves
• spatial resolution- fMRI images are thought to be accurate within 1-2 mm
• amplitude- the intensity or size of the activity
• frequency- the speed or quantity of activity
• EEG patterns produce two distinctive states- synchronised and desynchronised patterns
• synchronised- recognisable wave form
• desynchronised- no wave pattern
• alpha waves are associated with light sleep
• theta/delta waves are associated with deeper sleep
• EEG can also be used to detect illnesses like epilepsy and sleep disorders, and to diagnose other disorders that affect brain activity, like Alzheimer's disease
• amplitude with waves- how much the waves go up and down, and frequency- how close together each wave is to the next
• positive- has been historically important in understanding brain activity in areas such as sleep research and medical diagnosis
• Another benefit of EEGs is that they are a cheaper alternative to methods such as an FMRI and we are able to use EEGs with experiments involving movement
• very good temporal accuracy, measuring brain activation with a resolution measured in milliseconds