F6- EEG

The highest frequency band in the EEG, typically starting at 30 Hz, associated with cognitive functions like memory and sensory processing.

A theory suggesting that gamma waves represent the synchronized activity of neurons working together to perform a specific function, like recognizing an object or moving a limb.

A technique that records electrical activity directly from the surface of the brain, useful for studying high-frequency brainwaves like gamma waves.

A brief, sharp spike in the EEG signal, often associated with epilepsy.

The potential difference in electrical charge recorded in response to a specific stimulus, commonly used to assess the integrity of sensory pathways.

A specific type of evoked potential that assesses the visual pathways from the eyes to the cortex.

The time it takes for a stimulus to reach the cortical target, measured in evoked potentials.

The different stages of sleep characterized by specific patterns of brainwave activity, measured using electroencephalography (EEG).

The recording of electrical activity in the brain using electrodes placed on the scalp.

A type of neuroimaging technique that measures brain activity by detecting changes in blood flow. It provides good spatial resolution but has a slower temporal resolution.

The frequency range of brain waves that are typically associated with normal wakefulness.

A type of brain wave that is typically associated with sleep.

A non-invasive technique that records brain electrical activity from the scalp, primarily used to diagnose epilepsy and sleep disorders.

A specialized cap placed on the head to record brain waves.

The difference in electrical potential between a recording electrode placed on the scalp and a reference electrode.

The synchronized activity of a large group of pyramidal neurons in the cerebral cortex is responsible for the EEG signal.

The point where a dendrite receives an input from another neuron, often generating a positive charge.

An area where current flows into a neuron, usually associated with an EPSP.

The EEG measures the sum of excitatory and inhibitory postsynaptic potentials from many neurons firing synchronously.

The EEG is a dynamic measure because it records the changes in electrical potential over time.

The EEG is a non-invasive technique, meaning it does not require surgery or punctures to record brain signals.

The EEG has a wide range of applications in medicine, including diagnosing epilepsy, sleep disorders, and brain tumors.

The hypothalamus, found in the posterior part of the thalamus, plays a crucial role in regulating various bodily functions like body temperature, hormone secretion, blood pressure, urine production, and more, impacting both vegetative and homeostatic balances.

The electroencephalogram (EEG) allows us to observe and classify different sleep stages, distinguishing between wakefulness, non-REM sleep (stages I to IV), and REM sleep.

Non-REM sleep is characterized by a gradual decrease in brain activity, muscle tone, and overall bodily functions as sleep deepens, reaching its lowest point in stage IV.

REM sleep (Rapid Eye Movement) is a stage of sleep characterized by brain activity similar to wakefulness, rapid eye movements, muscle paralysis, and vivid dreams.

The transition from stage I to stage IV non-REM sleep shows a gradual transition in EEG signals. Deeper sleep reveals bigger EEG amplitudes and lower frequencies.

Following a cycle of non-REM sleep stages, the body reverses back through these stages before entering the REM sleep phase.

While non-REM sleep is characterized by decreased activity, REM sleep exhibits increased heart rate, blood pressure, and metabolism, all of which are nearly as high as the awake state.

REM sleep is marked by the presence of spontaneous penile erections, which can be used as an indicator of the REM phase and potentially related reproductive system health.

Muscle movement during REM sleep is regulated by increased activity of GABAergic neurons in the pontine reticular formation, which inhibit lower motor neurons in the spinal cord.

GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter, meaning it decreases or stops the activity of other neurons, playing a crucial role in regulating sleep and muscle activity.

A group of cholinergic neurons in the reticular formation near the junction of the pons and midbrain that, when stimulated, induce wakefulness and arousal.

The RAS, located in the brainstem, interacts with the thalamus to regulate the transition between sleep and wakefulness.

Slow-wave sleep, characterized by high-amplitude, slow brain waves, is associated with deep sleep and is induced by stimulating the thalamus.

The pontine reticular formation (PRF) sends signals to the superior colliculus, which controls eye movements, leading to the rapid eye movements characteristic of REM sleep.

Brain waves during REM sleep originate from the activation of the PRF and propagate through specific pathways, including the lateral geniculate nucleus of the thalamus and the visual cortex.

Brain waves associated with REM sleep that originate in the PRF and travel through the thalamus to the visual cortex, contributing to the rapid eye movements and vivid dreams of REM.

fMRI is used to identify brain regions active during different sleep stages, including REM and non-REM sleep.

REM sleep is characterized by brain wave patterns that resemble wakefulness, but its neural origin is different, stemming from the activation of the PRF.

The brainstem is involved in controlling wakefulness, while the thalamus plays a crucial role in regulating sleep.

While both REM and non-REM sleep have distinct brain wave patterns, they are both crucial for physical and mental restoration.