Body Rhythms and Mental States Chapter 3. Consciousness – The brain’s awareness of internal and external stimulation (*filter or interpretation of events.

Body Rhythms and Mental States

Chapter 3

Consciousness – The brain’s awareness of internal and external stimulation(*filter or interpretation of events NOT a direct copy)

What is the Nature of Consciousness?

The Functions and Structures of Consciousness

• Restricts attention

• Combines sensation with learning and memory

• Helps us select personally meaningful stimuli

• Allows us to draw on lessons stored in memory

Mental Control

• Attention

(limited resource)

*White Bear Study

• Automatic vs. Contolled Processes

• Preattentive Processes

Sleep and Dreaming

• Circadian rhythms• Rapid eye movements (REM)• Sleep paralysis, ‘paradoxical sleep’• REM rebound• Non-REM (NREM) sleep

Sleep Cycle

• NREM = 4 stages

*deepest sleep early in night

• REM replaces Stage 1

• 60-90 between REM

(most people have 4-6 cycles per night)

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.

The Sleep Cycle

The Need for Sleep

Over the years, the need for REM sleep decreases considerably, while the need for

NREM sleep diminishes less sharply

Why We Sleep• The exact function of sleep is uncertain

but the possible functions include: – eliminate waste products from muscles– repair cells– strengthen the immune system – recover abilities lost during the day – conserve energy– Aid in learning/memory

Why We Dream: A Cross-Cultural Perspective

• Folk theories (visions, religion)

• Scientific approach– Dreams as meaningful events– Dreams as random brain activity

Dreams as Meaningful Events

• To guard sleep (disguising images)

• To serve as sources of wish fulfillment

• Differences in dream content by age, gender, and culture

Dreams as Random Brain Activity

Hypnosis

Hypnosis – Induced state of altered awareness, characterized by heightened suggestibility and deep relaxation

Hypnotizability – Degree to which an individual is responsive to hypnotic suggestions

Altered Consciousness

Psychoactive drugs –

Chemicals that affect mental processes and behavior by their effects on the nervous system

HallucinogensHallucinogensStimulantsStimulants

DepressantsDepressants OpiatesOpiates

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.

Process of Addiction

Psychological• Dependence• Associations• People, Places, &

Things

Biological/Physical• Tolerance/dependence• Withdrawal