Consciousness

Body Rhythms Pages 156-160

Consciousness:Body rhythms and mental states

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Objectives: The student will

• Analyze body rhythms, including circadian rhythms

• Describe when the body is out of synch (the body clock)

• Summarize P.M.S.

Objective #1

• Consciousness- the process underlying the mental model we create of the world which we are aware

• Biological rhythms- Biological clock in our brains= governs hormone level, blood pressure, responsiveness of brain cells to stimuli

• Most B.R.’S= Endogenous, generated from within.

Understanding biological rhythms

ConsciousnessAwareness of oneself and the environment

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

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Objective #1

• Circadian Rhythms- bodily patterns that occur every 24 hours, most common sleep-wake

• However 100’s more, alertness, tasks• Circa (about) + dies (day)= 24 hour day• Work schedules, time change, staying up all

night to study, all effect cycle• Influenced by external cues• Participants in studies Awake 20-25 hours, sleep

for 10.

Circadian Rhythms

Endogenous biological rhythms

Circadian rhythmsOnce about every 24 hoursExample: the sleep-wake cycle

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Circadian rhythmsOccur in animals, plants, and people

To study endogenous circadian rhythms, scientists isolate volunteers from time cues.

Suprachiasmatic nucleusLocated in hypothalamus, regulates melatonin, a hormone secreted by the pineal gland

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Body’s Clock

• C.R.’S controlled by biological clock= super cluster of cells in hypothalamus called Suprachiasmatic ( soo-pruh-kie-as-MAT-ick) nucleus (SCN)

• Sends messages up neural pathways; responds to light and dark

• SCN regulates hormones and neurotransmitters• Melatonin, Pinal gland- Responds to light and dark• Darkened room-=melatonin rises O.T.O.H.

lightened room=falls

SCN

When the clock is out of synch

• Internal desynchronization- a STATE IN WHICH Biological rhythms are not in phase (synchronized) with one another

• Jet lag, body temp., hormone levels adjusted• new shift at work could be disaster; Exxon

Valdez, 3 mile island

Internal desynchronization

A state when biological rhythms are not in phase with each other

Circadian rhythms are influenced by changes in routine.Airplane flights across time zonesAdjusting to new work shiftsIllness, stress, fatigue, excitement, drugs, and mealtimes

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Internal des.

Moods and long term rhythms

• Birds migrate south, bears hibernate, sea creatures become inactive so effected by seasons

• Seasonal affective disorder ( SAD)- People become depressed when there is less sunlight

• Studies show lifetime of major seasonal depression 0.4%

Moods and long-term rhythms

Seasonal Affective Disorder (SAD)A controversial disorder in which a person experiences depression during the Winter and an improvement of mood in the Spring.

Treatment involves phototherapy or exposure to fluorescent light.

Evaluating frequency of and treatment for SAD is difficult.

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SAD

Menstrual Cycle affect moods

• 1st half of cycle more estrogen lines uterus for possible baby

• Mid cycle release the egg, produce progesterone

• Then if conception does not occur, E. & P. fall• So does physical changes correlate to

emotional or intellectual changes?

P.M.S.

• 1970’s vague cluster of physical and emotional problems days before menstruation

• Fatigue, irritability, headache, depression• Premenstrual syndrome- 13% to “most

women”• Physical symptoms, cramps, breast tenderness• However just like sad many more people think

they have symptoms than actually do

Menstrual cycles and mood

Physical symptoms are commonCramps, breast tenderness, and water retention

Emotional symptoms are rareIrritability and depressionFewer than 5% of women have symptoms predictably.

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Why women overestimate “PMS”

They notice depression or irritability when these moods occur premenstrually but overlook times when moods are absent premenstrually.

They attribute irritability before menstruation to PMS and irritability at other times to other causes.

They are influenced by cultural attitudes and myths about menstruation.

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Research conclusions about “PMS”

No gender differences in mood

No relation between stage of menstrual cycle and emotional symptoms

No consistent “PMS” pattern across menstrual cycles

No connection between “PMS” and behavior

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Summaries

• Circadian rhythms• Body clock• P.M.S.