2. EEGs and Brain Functions Flashcards
What do EEGs measure?
EEGs record spontaneous brain activity from millions of cells via scalp electrodes, measuring gross electrical activity and producing brain waves.
What are two key applications of EEGs?
Differentiate between awake and asleep states.
Determine legal death in certain countries.
What are event-related potentials (ERPs)?
ERPs are EEG responses to specific stimuli, such as light flashes or sounds, averaged to ensure reliability.
How are ERPs used in research and medicine?
Detect hearing problems in infants.
Study psychological processes like attention.
What characterizes normal brain activity in EEGs?
Normal brain activity is typically desynchronized across different brain regions.
What happens to brain activity during seizures?
Brain activity becomes synchronized, appearing as spike-and-wave patterns in EEGs.
Describe tonic-clonic seizures.
-Involve loss of consciousness and convulsions.
-Show synchronized EEG activity across the brain.
What are simple partial seizures (absence attacks)?
-Short (5–15 seconds) with spike-and-wave EEG patterns.
-No muscle activity but involve unawareness of surroundings.
What are complex partial seizures?
Affect specific brain regions, causing symptoms like auras or behavioral changes depending on the activated region.
What treatments are available for epilepsy?
-Antiepileptic drugs to reduce neuron excitability.
-Cannabidiol (CBD) as a potential treatment (requires more trials).
-Surgical removal of seizure-prone areas in severe cases.
What was Wilder Penfield’s contribution to neuroscience?
Developed brain mapping by stimulating cortical regions during awake surgery to localize seizure origins and cortical functions.
What did Wilder Penfield discover about brain function?
-Opposite brain sides control opposite body sides.
-Identified sensory and motor regions (forming the homunculus).
-Stimulation elicited memories, emotions, and behaviors.
What is the significance of the homunculus map?
It shows that brain function is spatially organized, with distortions reflecting sensory sensitivity and motor control importance.
What did Penfield’s findings reinforce about the brain?
Mental processes arise from physical brain activity.
