review midterm summary q&a.docx

What does PSG stand for? - Polysomnography What are three ways we can measure sleep? - Phenomenology - Behavior - Physiology What are the three signals from the body measured in PSG? - Electroencephalogram - Electrooculogram - Electromyogram ways we can identify sleep using b...

What does PSG stand for? - Polysomnography What are three ways we can measure sleep? - Phenomenology - Behavior - Physiology What are the three signals from the body measured in PSG? - Electroencephalogram - Electrooculogram - Electromyogram ways we can identify sleep using behavior alone. - Circadian timing (day/night) - Non-responsive but reversible - Rebound after deprivation - Low muscle tone - Horizontal position Which two stages of sleep are considered together as "Slow Wave Sleep"? - NREM 3 & 4 Which stage of sleep is associated with the absence of muscle tone, eye movements, and fast frequency, desynchronized EEG activity? - REM Which stage of sleep features K- complexes and sleep spindles? - NREM Stage 2 On average, how long is the NREM-REM cycle in humans? - 90 minutes Which phase(s) of sleep or wake are associated with high frequency, low amplitude, desynchronized brain waves? - REM or Wake During which state are the three primary neuromodulators regulating sleep/wake in balance? - Wake What are the 3 basic, critical structures involved in regulating sleep/wake states and their roles - Brainstem (power source) - Thalamus (sensory gate) - Cortex (information processing) Which cortical region is inactive during REM sleep? - Lateral Prefrontal Cortex What are PGO waves associated with? - Rapid eye-movements and scene changes in dreams Describe the neurochemical difference between NREM and REM in terms of the three primary neuromodulators regulating sleep/wake - NREM: Acetylcholine (ACh) is at its lowest and norepinephrine (NE) and serotonin (5HT) are lower than wake. - REM: NE and 5HT are at lowest levels while ACh is at highest level In what aspect are circadian rhythms "endogenous" rhythms? - Circadian rhythms are self-generated and persist without external cues (Mammoth Cave study) What is the role of melatonin in circadian rhythms and sleep (in humans)? - Released in response to darkness, helps regulate the onset of sleep at night What is a "zeitgeber"? Provide 2 examples - An external (exogenous) cue that (re)sets the circadian (SCN) clock. E.g. light, activity, food, temperature, social cues What is jet-lag and why is it harmful? - A mismatch between the biological clock and the day-night cycle. It is harmful because it is causes disorganized and misaligned circadian rhythms. Describe the two process model of sleep - Process C is the circadian process that creates daily biological rhythms (melatonin). - Process S is sleep homeostasis, regulated by sleep pressure which builds up the longer you are awake (adenosine) What proportion of animals have some form of sleep? - All animals have some form of sleep. What did Barrett Klein's research tell us about sleep in bees? - Bees have a state of reduced activity in which they are (reversibly) unresponsive, have reduced muscle tone, and this follows a circadian rhythm What is special about avian (bird) NREM sleep observed in certain species? - Unihemispheric SWS (half the brain in NREM, and the other half awake) Why is DARPA studying the white-crowned sparrow? - In order to build a 'super- soldier', who, like the sparrow, can stay awake for up to 2 weeks, without the negative effects of sleep deprivation. In what settings might humans also display (partial) unihemispheric NREM sleep? - In new sleeping settings (first night effect) Name one way in which the sleep of an infant might differ from that of an older adult. - Infants sleep polyphasically - more REM sleep - more sleep each day In what 3 ways does sleep change from childhood into old age? - Decreasing REM - decreasing SWS - more night awakenings with age What is the stable NREM:REM ratio for an adult? - 4(NREM):1(REM) What is the benefit of increased sleep spindle density during a nap for children? - Increased memory retention, and reduced forgetting Older adults get less sleep. Do they simply need less sleep than younger adults? - Older adults have difficulty getting enough sleep but they need just as much sleep as younger adults.