BODY RHYTHMS AND MENTAL STATESHow do you know you are not dreaming right now?

How many of you have text messaged while driving a car.

Key Terms and Ideas Consciousness – refers to different levels of awareness of one’s

thoughts and feelings. It may include creating images in one’s mind, following one’s thought process, or having unique emotional experiences

Continuum of consciousness – refers to a wide range of experiences ranging from being acutely aware and alert to being totally unaware Controlled processes – activities that require full awareness,

alertness and concentration to reach a goal. The attention required in carrying out controlled processes can

interfere with the execution of other activities Examples (driving a car)

Automatic processes – activities that require little awareness, take minimal attention, and do not interfere with other ongoing activities Examples (driving a car) Study by researchers at the University of Utah found that

motorists who talked on hands-free cellphones were 18 percent slower in braking and took 17 percent longer to regain the speed they lost when they braked.

4 x’s more like to get into an accident serious enough to injure themselves

Daydreaming – activity that requires a low level of awareness, often occurs during automatic processes, and involves fantasizing or dreaming while awake Men’s and women’s daydreams are similar (frequency,

vividness and realism Altered States – results from using any number of

procedure, ( such as meditation, psychoactive drugs, hypnosis or sleep deprivation) to produce an awareness that differs from normal consciousness. We perceive our environment or world in ways different

from normal perception. Sleep and dreams

Sleep – consists of five different stages that involve different levels of awareness, consciousness, and responsiveness, as well as different levels of physiological arousal

Deepest state of sleep borders on unconsciousness Dreaming – a unique state of consciousness in

which we are asleep but experience a variety of astonishing visual, auditory, and tactile images.

Natural Body Rhythms

Biological rhythm – a periodic, more or less regular fluctuation in a biological system; it may or may not have psychological implications

Controlled by the “biological clock” Endogenous – generated from within rather

than by external cues - how?

Endogenous Biological Rhythms

Circadian Rhythms Occur about every 24 hours. Example:The sleep-wake cycle.

Infradian Rhythms Occur less often than once a day. Examples include birds migrating, bears

hibernating. Menstrual cycle 28 days

Ultradian Rhythms Occur more frequently than once a day, about

every 90min. Examples include stomach contractions and

hormone levels.

Biological Rhythms

1. Annual cycles: On an annual cycle, geese migrate, grizzly bears hibernate, and humans experience seasonal variations in appetite, sleep, and mood. Seasonal Affective Disorder (SAD) is a mood disorder people experience during dark winter months.

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Biological rhythms are controlled byinternal “biological clocks.”

Biological Rhythms

2. 28-day cycles: The female menstrual cycle averages 28 days. Research shows menstruation may not affect moods.

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Biological Rhythms

3. 24-hour cycles: Humans experience 24-hour cycles of varying alertness (sleep), body temperature, and growth hormone secretion.

4. 90-minute cycles: We go through various stages of sleep in 90-minute cycles.

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The Biological Clock Suprachiasmatic nucleus (SCN) – teardrop-

shaped cluster of cells in the hypothalamus that governs circadian rhythms. Receives direct input from the eyes

Blind patients – some fully blind logical result of an internal clock mechanism that "runs

free” If scientists cut the optic nerve conveying information

from the retina to the brain, mice lose their normal circadian rhythms

Regulates melatonin and other hormones During sleep melatonin levels rise & fall during with

daylight (light)

Problems Internal desynchronization – biological

rhythms are out of synch. Examples

Jet lag - hormone and temperature cycles take longer the sleep/wake

New working hours (shifts) Seasonal affective disorder - see handout

Alaska Science Forum Tragic accidents related (pg 151 handout)

Copyright ©1998 BMJ Publishing Group Ltd.

Hastings, M. BMJ 1998;317:1704-1707

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