Variations in Consciousness

A.P. Psychology

12/18/2009

Drill ~ 12/18/2009

• What is the major difference between the conscious, preconscious and unconscious mind?

Circadian Rhythm24 hour biological cycles

Circadian Rhythms

• Especially influential for sleep, but also influence:– Blood pressure– Urine production– Hormonal secretions– Alertness– Short-term memory– Cognitive performance

• CR’s leave us primed to fall asleep most easily at a particular time of the day

• Example:– Body Temperature

fluctuation• Research shows that we

tend to fall asleep as our body temperature begins to drop and awaken when it begins to rise again

Ignoring Circadian Rhythm’s

• If you ignore your biological clock– Quality of sleep suffers– Jet Lag ~ traveling across time zones

• Leads to fatigue, sluggishness, and irritibility• Chronic Jet Lag leads to deficits in cognitive

performance• Readjustment?

– Takes about a day for each time zone traveled through

– Depends on the direction traveled as well (easier to fly westward than eastward) ~ has a significant impact on sports teams

Melatonin & Circadian Rhythm

• a hormone that seems to regulate the human biological clock

• Studies show that Melatonin can reduce the effects of jet lag

• Studies are inconsistent because timing of the dosage is key

• Melatonin may also be used as a mild sedative

• More effective when given in the daytime than at night

• It has also been hailed as a miracle drug for AIDS, Cancer, and sexual enhancement

• There is no research to support this

We spend about 8 hours per day, 56 hours perweek, 240 hours per month

and 2,920 hours per year doing

it...that's right...SLEEPING.

The Sleep & Waking Cycle

• Sleep is very misunderstood

• People think we do “nothing” while we sleep

• In reality, sleepers experience quite a bit of physical & mental activity throughout the night

• How do we know?• Much research has been done in sleep

laboratories, where volunteer subjects spend the night

Recording Devices

• Electroencephalograph• Records brain waves

– Beta (13-24 cps)» Normal waking

thought– Alpha (8-12 cps)

» Deep relaxation, blank mind and meditation

– Theta (4-7cps)» Light sleep

– Delta (less than 4 cps)» Deep sleep

• Electromyograph• Records muscle activity

and tension

• Electrooculograph• Records eye movement

• Other devices monitor heart rate, breathing, pulse rate and body temperature

The Sleep Cycle

• Stages 1 – 4• Stage 1 brief transitional stage of light sleep and lasts

about 1 – 7 minutes. Breathing & heart rate slow» Hypnic Jerks brief muscular contractions that occur

as people fall asleep

• Stages 2 – 4 respiration rate, heart rate, muscle tension, and body temperature continue to decline

– Stage 2 10 – 25 minutes

» Sleep Spindles brief bursts of higher frequency brain waves

– Stage 3 & 4 Slow Wave Sleep

» High amplitude, low frequency delta waves become prominent

REM & NREM Sleep

• REM Sleep– Rapid eye movement

• Irregular breathing & pulse rate

– Relatively deep sleep marked by eye movement, high-frequency, low-amplitude brain waves and vivid dreaming

– Sometimes called “Paradoxical Sleep”

• NREM Sleep– Stages 1 – 4 where

eye movement is absent

– Relatively little dreaming takes place here

– EEG activity is varied