Role of Conscious and Biorhythms in Organism’s Activity

Consciousness and its mechanisms

Consciousness is special form of perceiving surroundings and goal-orientated activity of person with interrelation to surroundings. Only social life forms consciousness. It involves life experience of entire society.

This ability of prefrontal areas to keep track of many bits of information could well explain abilities to prognosticate, do plan for the future, delay action in response to incoming sensory signals, consider the consequences of motor actions even before they are performed, solve complicated mathematical, legal, or philosophical problems, correlate all avenues of information in diagnosing rare diseases and control our activities in accord with moral laws.

The process of sensation and perceptual conclusions

The process of sensation results in the transmission of neural messages to the brain, where the psychological process of perception occurs.We actively construct perceptual conclusions about this sensory information.

In arriving at those perceptual conclusions, we are guided by well-established perceptual principles, such as the cues that typically indicate distance, movement, form, and so forth.

But our perceptual conclusions can also be influenced by a variety of psychological factors, including our expectations, learning experiences, and experiences that are unique to our culture.

The nativist position and empiricist position The Gestalt psychologists believed that

perceptual processes are inborn, a viewpoint called the nativist position. According to this position, people everywhere, whatever their background, see the world in the same way because they share the same perceptual rules.

Other psychologists have advocated the empiricist position, believing that people actively construct their perceptions by drawing on their prior learning experiences, including cultural experiences.

Consciousness studying Wilhelm Wundt’s investigations of consciousness,

begun in 1879, were central to the development of psychology as a field of study. Wundt’s approach, called structuralism, sought to determine the structure of consciousness by recording the verbal descriptions provided by laboratory subjects to various stimuli, a method that became known as introspection.

The next major approach to the study of consciousness was the functionalism of William James, who focused on how consciousness helps people adapt to their environment. Behaviorism, pioneered by John B. Watson in the early 1900s, shifted interest from conscious processes to observable behaviors, and the study of consciousness faded into the background for almost half a century, especially in the United States, until it was revived by the “cognitive revolution” that began in the 1950s and 1960s.

Consciousness: Sigmund Freud’s model The existence of different levels of consciousness was at the

heart of Sigmund Freud’s model of human mental functioning.

In addition to the conscious level, consisting of thoughts and feelings of which one is aware, Freud proposed the existence of the unconscious, a repository for thoughts and feelings that are repressed because they are painful or unacceptable to the conscious mind for some other reason.

He also formulated the concept of the preconscious, which functions as an intermediate or transitional level of mind between the unconscious and the conscious.

A preconscious thought can quickly become conscious by receiving attention, and a conscious thought can slip into the preconsciouswhen attention is withdrawn from it. In contrast, the repressed material contained in the unconscious can only be retrieved through some special technique, such as hypnosis or dream interpretation. (What Freud called the unconscious is today referred to by many psychologists as the subconscious.)

Consciousness: Carl Jung’s model Freud’s contemporary, Carl Jung, posited the

existence of a collective unconscious shared by all people which gathers together the experiences of previous generations.

The collective unconscious contains images and symbols, called archetypes, that Jung found are shared by people of diverse cultures and tend to emerge in dreams, myths, and other forms.

In Jung’s view, a thorough analysis of both the personal and collective unconscious was necessary to fully understand the individual personality.

Circadian rhythms In response to morning light, signals from

photoreceptors in the eye are relayed via the optic nerve to the suprachiasmatic nucleus. In turn, the suprachiasmatic nucleus causes the pineal gland to reduce the production of melatonin, a hormone that causes sleepiness.

As blood levels of melatonin decrease, mental alertness increases. Daily exposure to bright light, especially sunlight, helps keep the body’s circadian rhythms synchronized and operating on a 24-hour schedule.

Circadian Temperature Rhythm

The Biological Clock A tiny sliver of brain tissue, less than the size of a

pinhead, regulates the timing of our bodies. Within this sliver lies a biological clock that keeps track of the time of day, and seasons of the year, and marches our bodies and brains in step.

The small cluster of nerve cells that forms the biological clock is called the suprachiasmatic nucleus (SCN). Its name derives from the location of the SCN, just above where the broad optic nerve trunks cross over each other (a site known as the "optic chiasm") on their way back from the eyes to the visual center of the brain.

The SCN also receives information about light and dark from the eyes, but it has its own dedicated pathway of nerves, the retino-hypothalamic tract (RHT), which is separate from the main nerve bundles carrying visual information to the brain.

The Biological Clock• We know that the SCN is a biological clock because when it

is destroyed in an experimental animal by surgical pinpoint lesions of the brain, rhythms in sleep and wake, and many other rhythms, fade away. Interestingly, the animal, minus its SCN, runs, eats and drinks the same total amount each 24 hours, but these activities are now randomly distributed throughout the day and night.

• One final fact about human biological clocks -- they actually follow a pattern of about 25 hours. Hence, if someone lives in a cave or an apartment without windows (as people have done), their circadian patterns of sleep and wakefulness shift "westward" by about one hour a day. However, in the regular world, sunlight and darkness serve to "reset" the biological clock every day and keep us on a 24-hour cycle.

Suprachiasmatic nucleus Circadian rhythms are controlled by a master

biological clock-a tiny cluster of neurons in the hypothalamus in the brain. This cluster of neurons is called the suprachiasmatic nucleus.

The SCN is the internal pacemaker that governs the timing of circadian rhythms, including the sleep-wake cycle and the mental alertness cycle.

Keeping the circadian rhythms synchronized with one another and on a 24-hour schedule also involves environmental time cues. The most important of these cues is bright light, especially sunlight.

Normally the sleep-wake cycle, body temperature, and the melatonin cycle are closely coordinated.

Suprachiasmatic Nucleus (SCN)

Role of melatonin The decrease in available light is detected by the SCN

through its connections with the visual system. In turn, the SCN triggers an increase in the production of a hormone called melatonin.

Melatonin is manufactured by the pineal gland, an endocrine gland located in the brain. Increased blood levels of melatonin make a person sleepy and reduce activity levels.

At night, blood levels of melatonin rise, peaking between 1:00 and 3:00 A.M. Shortly before sunrise, the pineal gland all but stops producing melatonin, and a person soon wakes up.

As the sun rises, exposure to sunlight and other bright light suppresses melatonin levels, and they remain very low throughout the day. In this way, sunlight entrains, or sets, the SCN so that it keeps circadian cycles synchronized and operating on a 24-hour schedule.

Sleep People experience not only different levels,

but also different states of consciousness, ranging from wakefulness (which may be either active or passive) to deep sleep. Although sleep suspends the voluntary exercise of both bodily functions and consciousness, it is a much more active state than was once thought.

Tracking brain waves with the aid of lectroencephalograms (EEGs), researchers have identified six stages of sleep (including a pre-sleep stage), each characterized by distinctive brainwave frequencies.

Theories of sleep• Two theories of sleep, the repair and the adaptive theories,

attempt to explain why sleep occurs. • In the repair theory, sleep serves a biological need, replenishing

key areas of the brain or body which are depleted during the day.

• The adaptive theory suggests that sleep as a function evolved over time because it prevented early humans from wasting energy and exposing themselves to nocturnal predators, thus aiding in survival.

• REM sleep in particular has been thought to serve special functions. Research subjects whose REM sleep was interrupted made up for the loss by spending extra time in the REM stage on successive nights. It has also been suggested that REM sleep aids the activity of neurons that use the neurotransmitter norepinephrine, thus maintaining waking alertness. Persons deprived of REM sleep have shown poorer retention of skills learned during the day, leading to the hypothesis that REM sleep helps in assimilating daytime learning experiences.

Stage 1 NREM

• As the alpha brain waves of drowsiness are replaced by even slower theta brain waves, you enter the first stage of sleep. Lasting only a few minutes, stage 1 is a transitional stage during which you gradually disengage from the sensations of the surrounding world.

• Familiar sounds, such as the hum of the refrigerator or the sound of traffic, gradually fade from conscious awareness. During stage 1 NREM, you can quickly regain conscious alertness if needed. Although hypnagogic experiences can occur in stage 1, less vivid mental imagery is common.

• Although dreamlike, these images lack the unfolding, sometimes bizarre details of a true dream.

Stage 2 NREM

• Stage 2 represents the onset of true sleep. • Stage 2 sleep is defined by the appearance of sleep

spindles, brief bursts of brain activity that last a second or two, and K complexes, single but large high-voltage spikes of brain activity that periodically occur. Other than these occasional sleep spindles, brain activity continues to slow down considerably.

• Breathing becomes rhythmical. Slight muscle twitches may occur. Theta waves are predominant in stage 2, but large, slow brain waves, called delta brain waves, also begin to emerge.

• During the 15 to 20 minutes initially spent in stage 2, delta brain-wave activity gradually increases.

Stage 3 and Stage 4 NREM

• Stages 3 and 4 of NREM are physiologically very similar. Both stages are defined by the amount of delta brain-wave activity. In combination, stages 3 and 4 are sometimes referred to as slow-wave sleep.

• When delta brain waves represent more than 20 percent of total brain activity, the sleeper is said to be in stage 3 NREM.

• When delta brain waves exceed 50 percent of total brain activity, the sleeper is said to be in stage 4 NREM. During the 20 to 40 minutes spent in the night's first episode of stage 4 NREM, delta waves eventually come to represent 100 percent of brain activity. At that point, heart rate, blood pressure, and breathing rate drop to their lowest levels. However, his muscles are still capable of movement.

• The sleeper is approximately 70 minutes into a typical night's sleep and immersed in deeply relaxed stage 4 NREM sleep. At this point, the sequence reverses. In a matter of minutes, the sleeper cycles back from stage 4 to stage 3 to stage 2 and enters a dramatic new phase: the night's first episode of REM sleep.

REM Sleep

• During REM sleep, the brain becomes more active, generating smaller and faster brain waves. Visual and motor neurons in the brain activate repeatedly, just as they do during wakefulness.

• Dreams usually occur during REM sleep. Although the brain is very active, voluntary muscle activity is suppressed, which prevents the dreaming sleeper from acting out those dreams.

• REM sleep is accompanied by considerable physiological arousal. The sleeper's eyes dart back and forth behind closed eyelids-the rapid eye movements. Heartrate, blood pressure, and respirations can fluctuate up and down, sometimes extremely. Muscle twitches occur. In both sexes, sexual arousal may occur, which is not necessarily related to dream content.

• This first REM episode tends to be brief, about 5 to 15 minutes. From the beginning of stage 1 NREM sleep through the completion of the first episode of REM sleep, about 90 minutes have elapsed.

Beyond the First 90 Minutes

• Throughout the rest of the night, the sleeper cycles between NREM and REM sleep. Each cycle lasts about 90 minutes on average, but the duration of cycles may vary from 70 to 120 minutes.

• Usually, four more 90-minute cycles of NREM and REM sleep occur during the night. Just before and after REM periods, the sleeper typically shifts position.

• Stages 3 and 4 NREM, slow-wave sleep usually occur only during the first two 90-minute cycles. As the night progresses, REM sleep episodes become increasingly longer and less time is spent in NREM.

• During the last two 90-minute sleep cycles before awakening, NREM sleep is composed primarily of stage 2 sleep and periods of REM sleep can last as long as 40 minutes.

Disrupting the sleep-wake cycle

• As with many other physiological processes, sleep is linked to a 24-hour circadian rhythm and affected by signals such as light and dark. The effects of disrupting the sleep-wake cycle can be seen in jet lag, which is characterized by fatigue, irritability, lack of alertness, and sleeping problems.

• A person affected by jet lag feels like sleeping at the wrong times of day. It has been found that the body maintains a circadian sleep-wake rhythm even in the absence of external cues like lightness and darkness, although research subjects deprived of such cues eventually adopt a 25-hour “day.”

• The “internal clock” that maintains this pattern is a section of the brain called the supra chiasmatic nucleus (SCN), located in the hypothalamus.

Disorders interfering with sleep

• Various disorders interfere with sleep. The most common is insomnia, the inability to fall asleep or stay asleep. Nearly one-third of all Americans are affected by some degree of insomnia. Often associated with mental distress, insomnia is treated with medication, psychotherapy, relaxation techniques, or a combination of these methods.

• The medications most commonly prescribed are benzodiazepines (Valium, Halcyon, Restoril) and barbiturates. While they alleviate insomnia in the short run, these drugs interfere with normal sleep patterns, and can lead to increased tolerance and dependence.

• Researchers and clinicians have had success treating insomnia with the hormone melatonin, a naturally occurring substance related to sleep onset and secreted by the pineal gland.

Sleep disorders• Narcolepsy, a disorder characterized by sudden and uncontrollable

occurrences of sleep, afflicts 100,000 people in the United States. This condition is genetically linked, and may be curable in the future. Individuals affected by narcolepsy abruptly enter REM sleep states during the daytime, collapsing and remaining immobile for a period of time after awakening. Napping and stimulants have both been used to treat this condition.

• Another disorder associated with sleep is sudden infant death syndrome (SIDS), in which a healthy baby stops breathing during sleep, fails to awaken, and suffocates. While the exact cause of SIDS is unknown, researchers are attempting to identify and save at-risk infants by studying the relationship between the disorder and sleeping patterns.

• In sleep apnea, a person repeatedly stops breathing while asleep but awakes each time. The disrupted sleep that results from these multiple awakenings leaves the sleeper fatigued and sleepy during the daytime.

• Night terrors are non-REM dream experiences from which the sleeper never fully awakes and which he or she does not recall upon awakening. This condition mostly occurs in children and can be treated with hypnosis or medication in severe cases.

Chronic sleep problems

• An estimated 15 percent of Americans have chronic sleep problems, while about 10 percent have occasional trouble sleeping.

• Sleep disorders are listed among the clinical syndromes in Axis I of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders.

• They may be either primary (unrelated to any other disorder, medical or psychological) or secondary (the result of physical illness, psychological disorders such as depression, drug or alcohol use, stress, or lifestyle factors, such as jet lag).

Sleep deprivation • Sleep deprivation appears to be a precipitating factor for

seizures in some people with epilepsy. The reason why this should be so is unclear. It may be due to neurochemical or hormonal changes or it is possible that the normal increase in protein synthesis that occurs in sleep may be impeded, thereby diminishing cellular repair mechanisms and rendering brain cells more open to epileptic activity. However, sleep deprivation may also be used by doctors to activate EEG abnormalities in patients when a diagnosis of epilepsy is unclear.

• In conclusion, people whose seizures are triggered by changes in sleep patterns should be advised to maintain reasonably regular hours of retiring and awakening, to obtain sufficient sleep, and to avoid shift work or other causes of disrupted sleep-waking rhythms. There is not need to exceed average hours of sleep to reduce the chances of seizures occurring.

Hypnosis• Certain waking states, which are accompanied by marked

changes in mental processes, are considered states of altered consciousness. One of these is hypnosis, a highly responsive state induced by a hypnotist through the use of special techniques. While the term “hypnosis” comes from the Greek word for sleep (hypnos), hypnotized people are not really asleep. Their condition resembles sleep in that they are relaxed and out of touch with ordinary environmental demands, but their minds remain active and conscious.

• Other characteristics of hypnosis include lack of initiative, selective redistribution of attention, enhanced ability to fantasize, reduced reality testing, and increased suggestibility. Also, hypnosis is often followed by post-hypnotic amnesia, in which the person is unable to remember what happened during the hypnotic session.

• Hypnosis has proven useful in preventing or controlling various types of pain, including pain from dental work, childbirth, burns, arthritis, nerve damage, and migraine headaches.

Degrees of hypnosis• There are three degrees of hypnosis. Under light hypnosis, the

subject becomes sleepy and follows simple directions; under deep hypnosis, the person experiences dulling of sensory perception, similar to that of anesthesia.

• Under deep hypnosis, the subject can move about, open his or her eyes, and can even undergo medical procedures with no additional anesthetic. Magicians and illusionists use deep hypnosis to make a subject behave in unusual ways, such as to suspend the subject’s body between two chairs in a posture that is completely stiff. The magician suggests that the subject’s body become stiff and rigid, and the result is muscle tension powerful enough to support the body completely.

• Many researchers contend that the key factor in hypnosis is the subject’s willingness to cooperate with the hypnotist, combined with the subject’s belief that hypnosis works. People who are easily hypnotized are described as “suggestible”; in fact, if the subject expects to be successfully hypnotized, it is much more likely that he or she will.

Hypnotic induction

• Hypnotic induction is the process by which hypnosis is accomplished. In most situations, an individual performs the induction on a willing subject. Classical hypnotic induction involves a series of steps.

• First, sensory input to the subject is restricted, and the subject is instructed to stop moving. Second, the subject’s focus of attention is narrowed. This may be accomplished by asking him or her to focus on a specific point of light or a spot on the wall.

• Finally, the hypnotist begins a pattern of monotonous repetition.

Employ hypnosis• Doctors also employ hypnosis as a method of pain

management for chronic headaches, backaches, severe burns, and during childbirth. In cancer treatment, hypnosis is used to control the side effects of chemotherapy and as a self-healing adjunct to chemotherapy.

• Hypnosis is also used for autoimmune diseases, sleep disorders, and skin ailments, including warts and rashes. Some surgeons use hypnosis in the operating room, not only to reduce the amount of anesthesia patients need, but also to lessen anxiety and postoperative swelling and bleeding.

• A patient in an hypnotic trance can remain immobile for extended periods of time, avoiding aggravation of the injury.

• Victims under a state of shock are also more responsive to hypnotic induction. Dentists use hypnosis to complete dental work on a relaxed patient without the need for anesthesia.

Professional organizations

• A number of professional organizations offer training and advanced training in hypnosis.

• Among these are the American Society of Clinical Hypnosis, the American Board of Medical Hypnosis, the American Board of Psychological Hypnosis, the American Board of Hypnosis in Dentistry and the American Hypnosis Board for Clinical Social Work. The American Psychiatric Association, the American Psychological Association, and the American Dental Association have all endorsed the technique.

• Mental health professionals have used hypnosis to treat sexual dysfunction, eating disorders, smoking and other addictions, enuresis and thumb-sucking.

Meditation

• In meditation, an altered state of consciousness is achieved by performing certain rituals and exercises. Typical characteristics of the meditative state include intensified perception, an altered sense of time, decreased distraction from external stimuli, and a sense that the experience is pleasurable and rewarding.

• While meditation is traditionally associated with Zen Buddhism, a secular form called Transcendental Meditation (TM) has been widely used in the United States for purposes of relaxation. It has been found that during this type of meditation, people consume less oxygen, eliminate less carbon dioxide, and breathe more slowly than when they are in an ordinary resting state.