Body Rhythms and Mental States

1. Body Rhythms and Mental States Chapter 5

2. Body Rhythms and Mental States • Biological rhythms: The tides of experience • The rhythms of sleep • Exploring the dream world • Consciousness-altering drugs • The riddle of hypnosis

3. Biological Rhythms: Tides of Experience • Understanding biological rhythms • Endogenous biological rhythms • Circadian rhythms • When internal clocks are out of sync • Moods and long-term rhythms • Menstrual cycles and moods

4. Understanding Biological Rhythms • Consciousness • Awareness of oneself and the environment. • Biological rhythms • A periodic, more or less regular fluctuation in a biological system; may or may not have psychological implications. • Entrainment • Biological rhythms are synchronized with external events such as changes in clock time, temperature, and daylight.

5. 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. • Ultradian Rhythms • Occur more frequently than once a day, about every 90min. • Examples include stomach contractions and hormone levels.

6. Circadian Rhythms • Occur in plants, animals, insects and people. • To study endogenous circadian rhythms, scientists isolate volunteers from time cues. • Supraciasmatic nucleus (SCN) • Located in the hypothalamus, responsible for circadian rhythms by regulating melatonin, a hormone secreted by the pineal gland.

7. When Internal Clocks are Out of Sync • Internal desynchronization • A state when biological rhythms are not in phase with one another. • Circadian rhythms are influenced by changes in routine. Examples include: • Airplane flights across time zones. • Adjusting to new work shifts. • Also, illness, stress, fatigue, excitement, drugs, and mealtimes.

8. Moods and Long-term Rhythms. • Seasonal Affective Disorder (SAD) • A controversial disorder in which 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.

9. Menstrual Cycles and Mood • Physical symptoms are common. • Cramps, breast tenderness and water retention. • Emotional symptoms are rare. • Irritability and depression. • Fewer than 5% of women have symptoms predictably.

10. Why women overestimate “PMS” • They notice depression or irritability when these moods occur premenstrually but overlook times when moods are absent premenstrually. • The attribute irritability before menstruation to PMS and attribute irritability at other times to other reasons. • They are influenced by cultural attitudes and myths about menstruation.

11. Research conclusions about “PMS” • No gender differences exist in mood. • There is no relation between stage of menstrual cycle and emotional symptoms. • No consistent “PMS” pattern exists across menstrual cycles.

12. The Rhythms of Sleep • Why we sleep • When we don’t get enough sleep • The realms of sleep

13. Why We Sleep • The exact function of sleep is uncertain but sleep appears to provide time for: • the body to eliminate waste products from muscles, • repair cells, • strengthen the immune system, or • recover abilities lost during the day.

14. Sleep Disorders • Sleep deprivation leads to decreases in physical and mental functioning. • Sleep apnea • Breathing briefly stops during sleep, causing the person to choke and gasp and momentarily waken. • Narcolepsy • A sleep disorder involving sudden and unpredictable daytime attacks of sleepiness or lapses into REM sleep. • Staying up late and not allowing oneself enough sleep • 2/3 of North Americans get fewer than recommended 8 hours

15. Realms of Sleep • Stage 1. Feel self drifting on the edge of consciousness. • Stage 2. Minor noises won’t disturb you. • Stage 3. Breathing and pulse have slowed down. • Stage 4. Deep sleep. • REM. Increased eye movement, loss of muscle tone and dreaming.

16. A typical night’s sleep for a young adult

17. Exploring the Dream World • Dreams as unconscious wishes • Dreams as reflections of current concerns • Dreams as a by-product of mental housekeeping • Dreams as interpreted brain activity

18. Dreams as Unconscious Wishes • Freud concluded that dreams provide insight into our unconscious. • Manifest content includes aspects of the dream we consciously experience and latent content includes unconscious wishes and thoughts symbolized in the dream. • To understand a dream we must distinguish manifest content from latent content. • Not everything in dream is symbolic.

19. Dreams as Reflections of Current Concerns • Dreams may reflect ongoing conscious issues such as concerns over relationships, work, sex or health. • Dreams are more likely to contain material related to a person’s current concerns than chance would predict. • Example: university students and testing • Males and females appear to dream about similar issues now that lives and concerns of two sexes have become more similar.

20. Dreams as By-product of Mental Housekeeping • Unnecessary neural connections in the brain are eliminated and important ones are strengthened. • The brain divides new information into “wanted” and “unwanted.” • What we recall as dreams are only brief snippets from scanning and sorting that occurs during REM sleep.

21. Dreams as Interpreted Brain Activity • Activation-synthesis theory • Dreaming results from the cortical synthesis and interpretation of neural signals triggered by activity in the lower part of the brain. • At same time, brain regions that handle logical thought and sensation from the external world shut down.

22. Consciousness-altering Drugs • Classifying drugs • The physiology of drug effects • The psychology of drug effects

23. Classifying Drugs • Psychoactive drug • Substance capable of influencing perception, mood, cognition, or behaviour. • Types • Stimulants • speed up activity in the CNS. • Depressants • slow down activity in the CNS. • Opiates • relieve pain. • Psychedelic drugs • disrupt normal thought processes.

24. The Physiology of Drug Effects • Psychoactive drugs work by acting on brain neurotransmitters. These drugs can: • increase or decrease the release of neurotransmitters, • prevent reabsorption of excess neurotransmitters by the cells that have released them, • block the effects of neurotransmitters on receiving cells, or • bind to receptors that would ordinarily be triggered by a neurotransmitter or a neuromodulator.

25. Cocaine’s Effect on the Brain • Cocaine blocks the brain’s reabsorption (“reuptake”) of the neurotransmitters dopamine and norepinephrine, so levels of these substances rise. • The result is an overstimulation of certain brain circuits and a brief euphoric high. • When drug wears off, depletion of dopamine may cause user to “crash.”

26. The Psychology of Drug Effects • Reactions to psychoactive drugs depend on: • Physical factors such as body weight, metabolism, initial state of emotional arousal and physical tolerance. • Experience or the number of times a person has used a drug. • Environmental factors such as where and with whom one is drinking. • Mental set or expectations for drug’s effects.

27. The Riddle of Hypnosis • Defining hypnosis • The nature of hypnosis • Theories of hypnosis

28. Defining hypnosis • A procedure in which the practitioner suggests changes in the sensations, perceptions, thoughts, feelings or behaviour of the subject.

29. The Nature of Hypnosis • The hypnotic state is not sleep. • Hypnotic responsiveness depends more on the person being hypnotized than on the skill of the hypnotist. • Hypnotized people can’t be forced to do things against their will. • Feats performed under hypnosis can be performed by motivated people without hypnosis.

30. The Nature of Hypnosis • Hypnosis doesn’t increase accuracy of memory. • Hypnosis doesn’t produce a literal re-experiencing of long-ago events. • Hypnotic suggestions have been used effectively for medical and psychological purposes.

31. Theories of Hypnosis • Dissociation theories • Hypnosis is a split in consciousness in which one part of the mind operates independently of the rest of the consciousness, or • During hypnosis, dissociation occurs between an executive control system in the brain (probably frontal lobes) and other brain systems involved in thinking and acting.

32. Theories of Hypnosis • Sociocognitive theories • Effects of hypnosis result from interaction between social influence of the hypnotist (socio) and the abilities, beliefs and expectations of the subject (cognitive). • Can explain “alien abduction” and “past-life regression.