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BNS 107 Week 14
Sleep and Consciousness
Term | Definition |
---|---|
Restorative sleep hypothesis | Species with higher metabolic rates typically spend more time in sleep |
adaptive sleep hypothesis | The amount of sleep depends on the availability of food and safety. Predators (lions) and animals that can hide (bats) sleep a lot. Vulnerable animals without shelter (cattle) and those that need to spend hours feeding (elephants) sleep little. |
circadian rhythms | A rhythm that is a day in length, such as the wake-sleep cycle. |
suprachiasmatic nucleus (SCN) of hypothalamus | A structure in the hypothalamus that was found to be larger in gay men than in heterosexual men, regulates the reproductive cycle in female rats, and is the main biological clock, controlling several activities of the circadian rhythm. |
zeitgeber | environmental stimuli that regulate sleep/wake cycle |
melatonin | sleep-inducing hormone released by pineal gland |
pineal gland | A gland located just posterior to the thalamus that secretes melatonin; it controls seasonal cycles in nonhuman animals and participates with other structures in controlling daily rhythms in humans. |
ultradian rhythms | rhythms that are shorter than a day in length |
retinal ganglion cells | |
melanopsin (circadian photopigment) | |
electroencephalogram (EEG) | A measure of brain activity recorded from two electrodes on the scalp over the area of interest and connected to an electronic amplifier; detects the combined electrical activity of all the neurons between the two electrodes. |
theta waves | Seen in the first stage of sleep, the EEG picks up on these waves and they hold a frequency of 4-7 Hz. |
sleep spindles | Seen in stage 2 of sleep, brief bursts of 12-to 14-Hz waves that appear to serve a gating function, preventing disruptive stimuli from reaching the cortex and waking the sleeper |
delta waves | Seen during Stages 3 and 4 of sleep (slow wave sleep), they are large and slow waves that are at a frequency of 1-3 Hz. |
REM (rapid eye movement) sleep | The stage of sleep during which most dreaming occurs; research indicates that it is also a time of memory consolidation during which neural activity from the day is replayed. The eyes dart back and forth horizontally during this stage. |
activation-synthesis hypothesis | During REM sleep, forebrain integrates brainstem neural activity with information stored in memory |
basal forebrain area (induces drowsiness) | adenosine is accumulated within this area during wakefulness, this ultimately induces drowsiness |
adenosine | a neurotransmitter that has sedative and depressive effects, blocking its receptors contributes to arousal. |
Iocus coeruleus (involved in waking) | a part of the brain that is important for alertness |
orexin maintains wakefulness | A neuropeptide released by lateral hypothalamic neurons that increases feeding and arousal; also known as hypocretin. It suppresses REM sleep and helps to sustain wakefulness |
insomnia | The inability to sleep or to obtain quality sleep, to the extent that the person feels inadequately rested. |
sleepwalking | Occurs during slow wave sleep, Can be triggered by stress, alcohol and sleep deprivation, and the individual may engage in complex behavior while sleepwalking |
narcolepsy | A chronic neurological disorder in which individuals fall asleep suddenly during the daytime and go directly into REM sleep. |
cataplexy | A disorder in which a person has a sudden loss of muscle strength (atonia) like that seen in REM sleep; the person may fall to the floor but remains awake. |
lucid dreaming | Dreamers are aware during a dream that they are dreaming. They can even learn to control the content of their dreams; they may decide before sleeping what they will dream about, or they may interact with characters in their dream. |
awareness | |
sense of self | self recognition: the ability to recognize oneself in a mirror sense of agency: the attribution of an action or effect to ourselves rather than to another person or external force |
anterior singulate gyrus and the insula | involved in a sense of body image |
mirror neurons | neurons that respond both when we engage in a specific act and while observing the same act in others |
what areas of the brain are involved in inducing sleep? What about waking? | |
Is there a genetic basis for narcolepsy and cataplexy? | yes |
what is a proposed function of mirror neurons? | It is believed that mirror neurons are used for social understanding (understanding the actions of others) |