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CHAPTER 4 CONSCIOUSNESS AND ITS VARIATIONS LECTURE NOTES Consciousness your immediate awareness of internal and external stimuli, such as thoughts, sensations, and memories. The subjective experience of consciousness has a sense of continuity one stream of conscious mental activity seems to effortlessly flow into the next. William James coined the term stream of consciousness This helps provide us with a sense of personal identity that has continuity from one day to the next. Psychologists often infer the conscious experience that seems to be occurring by carefully observing behavior. BIOLOGICAL AND ENVIRONMENTAL CLOCKS THAT REGULATE CONSCIOUSNESS Circadian rhythm biological processes that systematically vary over a 24-hour period Mental alertness and sleep/wake cycles are consistent. Your mental alertness has a daily pattern Ex) you hit a slump at 3pm, everyone feels tired at 3pm, time for a siesta Our master biological clock is governed by the suproachiasmatic nucleus (or SCN) The SCN is the internal pacemaker of the circadian rhythms The SCN is a tiny cluster of neurons in the hypothalamus Keeping circadian rhythms all synchronized together involved the help of environmental time cues Ex) bright sun light As the sun sets, light decreases SCN detects that there is less light SCN triggers an increase in melatonin Melatonin makes you sleepy, reduces activity levels Before sunrise, melatonin production stops As the sun rises, exposure to brighter light suppresses melatonin Thus, you become more active in the day light LIFE WITHOUT A SUNDIAL Free running conditions conditions where sun light does not influence circadian rhythms Researchers have built rooms in underground caves Volunteers live in these rooms for weeks/months at a time 2 major effects occur: 1. people tend to drift to a natural 25-hour day schedule 2. circadian rhythms lose their normal synchronization with one another When volunteers return to normal daylight, within days their bodies reset to the biological clock (return to 24-hour day schedule, circadian rhythms become synchronized again). Many blind people have free-running conditions b/c they are unable to detect light which sets the SCN--- they offer suffer from insomnia and other sleep problems JET LAG: Biological clock gets out of whack with the environmental clock This occurs when people travel across time zones Circadian rhythms get out of synch with your daylight/darkness cues Thinking, concentration, and memory are disrupted Experience physical and mental fatigue, depression, irratibility & disrupted sleep Melatonin production/release is messed up It can take a week or longer to adjust to jet lag NIGHT SHIFTS: Circadian rhythms are out of synch with daylight/darkness cues When sleeping during the daycompletely darken the room Trying to stay awake at nightuse lots of bright lights (trick your brain) MONDAY MORNING BRAIN FOG: We stay up later on the weekends and thus reset our clocks... View Full Document

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