Chapter 5 – Body Rhythms and Mental States
Consciousness is an awareness of self and environment. This change in mood, alertness, efficiency ebbs and flow
throughout the day.
Examining the on going rhythmic cycles is like watching a motion picture of consciousness; studying the person’s
distinct states of consciousness is like viewing each frame separately.
The chapter examines:
1) The Movie – how consciousness and functioning varies periodically over time - rhythmically.
2) A Frame in time (a state of consciousness) in the world of dreams
3) Re-touching the film (the influence of recreational drugs and hypnosis on consciousness)
We all experience dozens of periodic, fairly regular ups (waxing) and downs (waning) in physiological functioning. A
biological clock in the brain (a tear drop like shaped cluster of cells in the hypothalamus called the SCN supra-chi-asmatic nucleus) for example governs the waxing and waning of: hormone levels, urine volume, blood pressure and even
responsiveness of brain cells to stimulation.
*Supra means transcending above. Chiasma is a crossing or intersecting of two (nerve or ligament) tracts.
Biological Rhythm
A periodic somewhat regular fluctuation in a biological system, it may or may note have
psychological implications.
Internal (endogenous) biological rhythms are usually synchronized with external (exogenous) events such as changes
from day to night (circadian rhythm), seasonal changes in the calendar (infradian rhythms) and clock changes from
minute to hours throughout the day (ultradian rhythms). This internal-external synchronization is called entrainment (to
pull or carry along after one’s self).
The three categories of biological rhythms
1) Circadian rhythm – a biological rhythm of about 24 hours with a period from peak to trough of about 24 hours.
Example – the sleep-wake cycle among hundreds of others. Body temperature fluctuates one degree centigrade
each day rising (peaking) in later afternoon and hitting a low point in the wee hours in the morning.
2) Infradian rhythms occur less often than once a day, more at once a month or twice a season. Example, the human
female menstrual cycle which occurs every 28 days; birds migrate south for the winter and bears hibernate.
3) Ultradian rhythms occur more often than once a day, frequently on or about a 90-minute cycle. Other examples
include stomach contractions, hormone levels, susceptibility to visual illusions, verbal/spatial performance brain
wave responses during cognitive tasks alertness and daydreaming.
Why Study Biological Rhythms?
They affect everything, eg., the effectiveness of medication taken at different times of the day to alertness and
performance on the job.
1) Circadian rhythms occur in all life forms and is impacted by changes in light, air pressure temperature associated
with the earth’s rotation on its axis.
Our bodies adapt to a 24 hour cycle bodily rhythms become entrained by external cues. Studying endogenous rhythms
requires isolation from external cues (eg., clocks and other markers of night and day).
Subjects studied in controlled environments (underground caves, salt mines) isolating them from external cues with
one-way communication to the surface reveal the following:
Bodily norm reverts to a 24.3 hour cycle, when put on a 28 hour day cycle, body temperature and hormone levels follow
a 24.18 hour cycle (Czeisler et al., 1999).
The Body’s Clock
The suprachiasmatic nucleus SCN controls the body’s rhythms. Neural pathways in the back of the eyes feed signals
back to the SCN allowing it to respond to light and dark. It then sends out messages to the brain allowing it to adapt to
these changes.
Melatonin
The SCN regulates fluctuating levels of hormones and neurotransmitters, they in turn provide feedback that affect the
SCN’s functioning. During dark hours the SCN regulates melatonin, a hormone secreted by the pineal gland deep
within the brain. Darkness decreases the level of melatonin, brightness increases it. Melatonin appears to help the
biological clock keep phase with light-dark cycles (Haimov & Lavie, 1996; Lewy et al., 1992). Melatonin promotes
sleep, it is often absent in blind people.
The rhythms governed by the suprachiasmatic nucleus are synchronized with one another but may peak at different
phases, the peaking of one predicts the peaking of another. When the normal rhythms are thrown out of sync the
resulting internal de-synchronization compromises performance. Examples are the Exxon Valdez oil spill.
Shift workers would fare better were they allowed to establish a stable routine.
2) Infradian Rhythms Long Term Impact on Mood and other Cycles
Season Affective Disorder (SAD)is common during the winter months are may be the result of decrease sun light
(Rosenthal, 1998). Evidence for SAD comes form clinical case studies, extrapolations from patient cases. Surveys
places the prevalence of SAD as low as .4% and .01% for major/minor SAD (Blazer, Kessler & Swartz, 1998). There is
some evidence that photo (light) therapy may be an effective for SAD and some speculation that such patients may have
low levels of melatonin (Lewy et al., 1998).
Is SAD the result of realizing yet another birthday? Holiday blues? Decreased physical activities in the winter?
The Menstrual Cycle occurs on average every 28 days. During the first half of the cycle there is an increase in estrogen
and a thickening of the uterine lining in preparation for possible pregnancy. At mid cycle the ovaries release a mature
egg (an ovum). The ovum sac which contained the egg begins to produce progesterone which helps the uterine lining to
receive the egg. If pregnancy does not occur estrogen and progesterone levels fall and the uterine sloughs off as the
menstrual flow and the cycle begins again.
Symptoms associated with menstruation (observed cross culturally) includes: tenderness of the breasts, water retention
and abdominal cramps. Pre-menstrual syndrome, a term popularized during the 1970's to include symptoms such as:
irritability, fatigue, headache and depression appears uniquely a western concept (Parlee, 1994). Less than 5% of
women have such symptoms predictable over the course of their cycle (Brooks-Gunn, 1986; Reid, 1991). Menstruation
is cyclic but not for women beyond menopause.
Do women conform to behavior expected of someone who is pre-menstrual? Would eliminating the definition
eliminate psychological reality of the syndrome?
3 Ultradian rhythms occur more often than once a day, frequently on or about a 90-minute
cycle. The diurnal sleep cycle is an example of ultradina rhythm in motion.
Sleep
Question: What is the evolutionary adaptive function of sleep?
Answer: The function of sleep is…
Sleep Research
In 1955 a sleep researcher named Nathaniel Kleitman asked one of his graduate students to monitor the EEG of one of
his sleeping laboratory subjects, the graduate student William Dement noticed discernable brain wave activities which
he reported. Another graduate student Eugene Aserinsky was asked to observe, his observation concurred with his
colleague's. Thus was born the scientific study of sleep!
Sleep can be divided into four distinct stages
For a brief overview of the stages click here or for an expanded view click here.
Stage 1: light sleep, alpha waves - edge consciousness drifting off
Stage 2: deeper sleep than stage 1, still fast waves. 45% of sleep
Stage 3: deep, delta waves
Stage 4: deeper sleep
night terrors
sleep walking
Stage 5: REM... dreams, muscle paralysis nightmares
It takes between 30 - 40 minutes to reach stage 4, the stages then re-occur but in reverse order 3, 2, then 1, stage 1 then
become the Rapid Eye Movement stage some 70 - 90 minutes later.
REM sleep is embarked upon some 40 - 70 minutes after the end of stage 4. REM can be termed stage five sleep.
Stage 5 is characterized by long bursts of very rapid somewhat irregular spikes in brain wave patterns. The eyes move
rapidly as if tracking objects in motion. There is increased respiration and blood pressure, likewise penile and clitoral
erection occurs, there is also vaginal lubrication. Paradoxically, the skeletal muscles become limp disallowing physical
movement, in fact, this is termed paradoxical sleep. The first cycle of REM lasts between 5 - 20 minutes then gets
progressively longer as the night wears on. There is an 82% likelihood of dreaming at this stage and dreams are
reported as lucid Foulkes, 1962 reported 51% probability of dreams occurring during non-REM cycles.
The evolutionary adaptive function of REM sleep remains a mystery though several competing explanations are
posited:
1)
Unconscious Wishes - Psychoanalytic Theory (Freud ). Latent wishes, desires, impulses and other
forbidden thoughts are expressed (manifested) symbolically during dreams. The thoughts are disguised as
non-threatening symbols for us to interpret but not take literally. Flaws: The theory is farfetched and does not
provide a reliable way to interpret latent content accurately.
2)
Problem Focus (Siegel, 1991; Webb & Cartwright, 1978). Dreams serve to resolve ongoing conflicts and
concerns of waking life. For example, if going through a divorce, dreams are more likely to contain marital
related contents than would be predicted by chance occurrence (Cartright et al., 1998). Flaws: Doubt that
people are able to workout their conflicts while sound asleep, dreams are merely an expression of the problem,
insight may result only after people have had the change to figure out what was troubling them (Blagrove,
1996; Domhoff, 1998).
3)
By-Product of Mental Housekeeping (Evans, 1984; Crick & Mitchison, 1995). The brain prioritizes
weeding out the sensible form the non-sensible, strengthening neural connections between meaningful data
while weakening connections in the case of meaningless data. Similar processes may occur in the
strengthening of synaptic connections associated with recently stored memories - consolidating these
connections. Flaws: The information processing theories do not explain why some dreams reoccur throughout
the years, why some dreams are story-like in presentation. It may tell use more about REM than about dreams.
4)
Activation-Synthesis Theory (Allan Hobson, 1988, 1990). Lower brain regions such as the pons emit random
signals which are interpreted and synthesized by the cortex. The cortex imposes structure on the random
firings. Flaws: Our interpretation of these random firing (the sense we make out of them) may be more a
reflection of our concerns and conflicts. This theory however, does not explain the story-like quality of REM
and N-REM dreams.
Altered States of Consciousness
We began by using the movie analogy in describing consciousness, this is what we have covered thus far through our
journey into consciousness:
1)
The Movie – how consciousness and functioning varies periodically over time rhythmically.
2) A Frame in time (a state of consciousness) in the world of dreams
Now briefly, we shall attempt to re-touch the film by taking a closer look at recreational drugs and hypnosis on
consciousness. For a more in depth look at the topic click the link above or visit Dr. Charles T. Tart's archive, he has
written extensively on states of consciousness.
3) Re-touching the film (the influence of recreational drugs and hypnosis on consciousness).
Throughout history humans have attempted in one way or another to alter consciousness, we will quickly look at four
major classes of drugs and mention two others not yet officially classed.
A psychoactive drug is a substance that alters perception, emotion, mood, memory and the body's biochemistry. The
four major categories are:
Stimulants
Speeds up activities in the Central Nervous System to produce feelings of excitement, confidence
well-being or euphoria. Increasingly large doses causes jittering, anxiety, hyper-alertness, convulsion,
heart failure and death
Amphetamines -(met-amphetamines) are usually synthetic drugs in pill form. Cocaine naturally occurs in the leaf of the
coca plant, in refine form it can be injected, snorted or smoked, the effects are more immediate and
intense, the stimulants do not actually increase energy reserve, more the case that it depletes it. After
effects are fatigue, depression and irritability. Nicotine is a stimulant thought its effect is calming and
promotes alertness, it decreases an appetite for carbohydrates. Coffee and teas contain caffeine which
is a stimulant.
Depressants
Slows down the Central Nervous System to reduce guilt, anxiety, and tension. Increasing amounts
causes irregular heartbeat, convulsion, inhibited breathing, and death.
Alcohol
initially suppresses parts of the brain that inhibits impulses so one feels relaxed, euphoric, but then the
anesthetic effect begins with increasing consumption. While alcohol consumption does not cause
violent behavior, one is more likely to express impulsiveness and relinquish responsibility. Impaired
coordination and cirrhosis and permanent neurological impairments may result from chronic use or
abuse. Barbiturates - Phenobarbital; tranquilizers, valium and methaqualone are other
depressants/sedatives, addictive.
Opiates
Opiates are pain numbing, anxiety reducing and euphoric inducing substances which also decreases
motivation. May result in convulsion, coma and death. Opium derives from the opium poppy,
morphine from opium, heroin from morphine. Methadone is a synthetic drug. These drugs generally
mimic endorphins and have powerful effects on emotions.
Psychedelics
Disrupts normal perception of time, space and thought processes, produces visual hallucinations.
LSD (lysergic acid diethylamine) is a synthetic drug. Mescaline form the peyote cactus and
psilocybin (from certain species of mushrooms) are psychedelics. "Trips" may be very un/pleasant
mystical or nightmares.
Sub-classifications are
Anabolic
Steroids
Marijuana
Synthetic testosterone (pill or injection) increases muscle, may shrink the testes (normal production of
testosterone reduced due to the introduction elsewhere), some reported side effects aggression / rage,
confidence / courage.
Marijuana is from the plant Cannabis Sativa, the psychoactive ingredient THC (tetra hydro
cannabinol). Increases heart rate and intensifies the perception of colors and sound, a decrease sense
of time may appear to drag on. Impairs transfer of short term memory into long term memory.
Physiology of Drug Effects - Mechanism of Action
Psychoactive drugs primarily have their effect at the synaptic level, increasing or decreasing the release of
neurotransmitters, blocking their re-uptake or changing the effect on the receiving cell or by binding to the receptor site
that would ordinarily be triggered by a neurotransmitter or neuro-modulator.
Cocaine for example increases the level of nor-epinephrine and dopamine in the brain by blocking the re-absorption of
these substances, it may also increase the transmission of serotonin (Rocha et al., 1998).
Alcohol interferes with the work of serotonin on memory, information stored before a drinking session remains in tact
during the session but is retrieved more slowly (Stempel, Beckwith and Petros 1986).
Other synthetic drugs such as MDMA "Ecstasy" may cause permanent damage to cells that produce serotonin
(Ricaurate et al., 1988).
Tolerance
Use of psychoactive drugs such as heroin and tranquilizers may lead to tolerance - over time more of the drug is needed
to produce the same effect - discontinued use may result in withdrawal symptoms such as stomach cramps, nausea,
muscle spasms sleep loss and depression.
THEORIES OF HYPNOSIS
Disassociation Theory
(Ernest Hillgard 1977, 1986).
Like lucid dreaming, one part of the brain splits off and operates independently from the rest of consciousness, a part of
the brain not subject to hypnosis is watching as a hidden observer but not participating.
A related theory is that there is a disassociation between the executive control system (frontal lobes?) and the rest of the
brain. The executive part relinquishes control over the subordinate regions. Flaw: circular reasoning - we know that the
person is hypnotized because they are suggestible.
The Socio-cognitive Theory
The individual plays along and gets caught up in the role, in addition to wanting to please the hypnotist, the individual
even convinces him or herself of the situation. Flaw: Hypnosis is more of a trance-like state than is conscious pretense
and acting.