Chapter 19: Brain Rhythms and Sleep Flashcards
Chapter Chapter 19: Brain Rhythms and Sleep
What is the primary focus of Electroencephalogram (EEG) recordings?
EEG primarily focuses on measuring the collective activities of neuron populations over individual neuron activities.
Who is credited with describing the human EEG, noting differences between waking and sleeping EEG patterns?
Hans Berger, an Austrian psychiatrist, is credited with describing the human EEG.
What are the frequency ranges and characteristics of Delta EEG rhythms?
Delta rhythms, with frequencies less than 4 Hz, are slow, large-amplitude waves indicative of deep sleep.
How do Magnetoencephalography (MEG) and EEG differ in their recording techniques?
MEG records cerebral cortex rhythms via the magnetic fields generated by neuronal electrical currents, while EEG measures the electrical activity from the scalp’s surface.
What are the potential functions of cortical rhythms, as discussed in the chapter?
The exact function of cortical rhythms remains unclear, with theories suggesting they may serve to disconnect the cortex from sensory input during sleep or help coordinate perceptual processes during wakefulness by synchronizing neural activity across different brain regions.
What is sleep?
Sleep is a readily reversible state of reduced responsiveness to, and interaction with, the environment. (Coma and general anesthesia are not readily reversible and do not qualify as sleep.)
What are the two main behavioral states humans experience during a day?
Humans experience two main behavioral states during a day—waking and sleeping—which includes distinct phases of non-REM and REM sleep.
How is non-REM sleep characterized?
Non-REM sleep is characterized as a period of rest for both the body and brain, with reduced muscle tension, minimal movement, and decreased body temperature and energy consumption. The brain’s activity and neuron firing rates are at their lowest during this stage.
What are the characteristics of REM sleep?
REM sleep, known as the dreaming phase, is characterized by highly active brain activity, vivid dreams, and a state of paralysis in the body except for eye and respiratory muscles. Physiological control systems switch to sympathetic dominance during REM sleep.
Describe the sleep cycle.
Sleep cycles through non-REM and REM stages, with about 75% of sleep time in non-REM and 25% in REM, repeating roughly every 90 minutes. Non-REM sleep transitions from light to deep sleep before moving into REM sleep.
What are some proposed functions of sleep?
Sleep may serve essential functions related to brain health, memory consolidation, emotional processing, and neural plasticity.
How is sleep regulated in the brain?
Sleep involves active processes controlled by specific brain regions and neurotransmitter systems, including diffused modulatory neurotransmitter systems and the suprachiasmatic nucleus (SCN).
What regulates circadian rhythms?
Circadian rhythms are regulated by biological clocks, primarily the suprachiasmatic nucleus (SCN), which coordinates the body’s internal clocks with environmental cues like light-dark cycles.
Where are alpha rhythms prominent, and what behavioral state are they associated with?
Alpha rhythms are prominent over the occipital cortex and are associated with quiet, waking states.
What distinguishes mu rhythms from alpha rhythms?
Mu rhythms have a frequency range of 8–13 Hz and are similar to alpha rhythms but occur over motor and somatosensory areas.
