1. Body Rhythms and Mental States
How do you know you are not dreaming right now?
How many of you have text messaged while driving a car.

2. 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
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. 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.

5. 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?

6. 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.

7. Biological Rhythms Biological rhythms are controlled by
internal “biological clocks.”
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.
OBJECTIVE 2| Distinguish four types of biological rhythms, and give and example of each.

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

9. 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.

10. 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)

11. 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)

12. No Caption Found Hastings, M. BMJ 1998;317:1704-1707
Copyright ©1998 BMJ Publishing Group Ltd.