Chapter 6: Consciousness

Chapter Summary

• Consciousness is defined as our immediate awareness of our internal and external states. • The study of consciousness has proven difficult for researchers because of the difficulty measuring its associated phenomena, such as dreams and awareness. In part, the rise of behaviourism in the United States during the 1950s was a reaction to these difficulties, focusing more on objective behaviours that could be easily measured. • Recent developments in neuroimaging have allowed researchers to look at brain activity during various states of consciousness.

When We Are Awake: Conscious Awareness LEARNING OBJECTIVE 1 Define different levels of conscious awareness and describe key brain structures and functions associated with those levels.

• Attention is one of the key aspects of conscious awareness. Other key cognitive activities underlying cognitive awareness include monitoring (our implicit decisions about what to attend to), memory, and planning. • Most biological investigators believe that consciousness results from a combination of brain activities in several brain regions. Two key brain structures appear to be the cerebral cortex, which helps regulate our awareness of attentional processes, and the thalamus, which relays sensory information from various parts of the brain to the cerebral cortex for processing.

Preconscious and Unconscious States LEARNING OBJECTIVE 2 Summarize the ideas of preconscious and unconscious states, including Freud’s thinking on the unconscious.

• In addition to our conscious level of awareness, many psychologists believe there are other levels or degrees of consciousness, and distinguish conscious awareness from two other states—unconsciousness and preconsciousness. • Cognitive psychologists have demonstrated the existence of implicit memory; that is, memory that we do not consciously reflect upon but which, nevertheless, influences our behaviour. • Preconsciousness is a level of awareness in which information can become readily available to consciousness if necessary. • Unconsciousness is a state in which information is not easily accessible to conscious awareness. • Freud viewed the human unconscious as an important storehouse for knowledge and experience, which although not directly accessible to our conscious awareness, still influences our behaviour. • Although Freud’s ideas fell into disfavour for several years, in recent years, scientists have begun to re-examine the unconscious from different points of view. For example, implicit memory describes knowledge that we have and are able to apply to various tasks, without being able to recall it at will.

When We Are Asleep LEARNING OBJECTIVE 3 Describe what happens when people sleep, key theories of why we sleep and dream, and problems with sleep and how they affect functioning.

• Every 90 to 100 minutes when we sleep, we pass through a sleep cycle consisting of five different stages. The fifth stage of sleep, rapid eye movement, or REM sleep, is characterized by rapid and jagged brain-wave patterns and eye movements and irregularities in heart rate and breathing. Dreaming usually occurs during this phase of sleep. • Scientists have identified brain activities that maintain the regular rhythms of life. Our move from a sustained period of wakefulness into a period of sleep during each 24-hour period is known as a circadian rhythm. • Scientists have not reached a definitive conclusion about why people sleep, although some scientists have suggested sleep serves an evolutionarily adaptive function, keeping our ancestors away from predators that hunted at night. Others have suggested that sleep might play a role in growth, or allow us time to restore depleted chemical resources in the brain and body and eliminate chemical wastes that have accumulated throughout the day. • We also do not understand why people dream. Recent theories about dreams emphasize cognitive approaches. The information-processing theory of dreams suggests that dreams are the mind’s attempt to sort out and organize the day’s experiences and fix them in memory. The attention-synthesis hypothesis suggest that dreams are the mind’s attempts to give meaning to internally generated signals firing throughout the brain during deep sleep. Freud believed that dreams represent expressions of the internal desires and wishes that have been repressed and stored in the unconscious. • Sleep deprivation can lead to feelings of fatigue, irritability, and malaise, resulting in lower productivity and a tendency to make mistakes. Loss of sleep can also affect the functioning of the immune system. The regular inability to fall asleep or stay asleep is called insomnia. Other sleep disorders include sleep apnea, narcolepsy, sleepwalking, and night terrors.

Hypnosis LEARNING OBJECTIVE 4 Discuss theories and evidence about what hypnosis is, how it works, and how it can be used.

• Hypnosis is a suggestible state during which people can be directed to act in unusual ways, experience unusual sensations, remember forgotten events, or forget remembered events. • Ernest Hilgard’s theory suggests that hypnosis divides consciousness into two parts: one focused on the suggestions of the hypnotist, and the other a hidden observer. Other theorists suggest that motivated role-playing is at work in hypnosis. • Hypnosis has been used to successfully help control pain, as well as treat anxiety, skin diseases, asthma, insomnia, stuttering, high blood pressure, warts, and other forms of infection. Meditation LEARNING OBJECTIVE 5 Describe the techniques and effects of meditation.

• Meditation is designed to help turn one’s consciousness away from the outer world toward inner cues and awareness, and to ignore all stressors. • Like hypnosis, meditation has been suggested to have numerous positive benefits, including successfully treating many of the same illnesses, and helping people to relax.

Psychoactive Drugs LEARNING OBJECTIVE 6 List and describe common depressant, stimulant, and hallucinogenic psychoactive drugs and their effects.

• The three main classes of psychoactive drugs are depressants (substances that slow down brain activity), stimulants (substances that excite brain activity), and psychedelic or hallucinogenic drugs (substances that distort sensory perceptions). • Regular ingestion of some drugs can lead to maladaptive changes in a person’s behaviour patterns and physical responses, a pattern known as addiction. Signs of addiction can include increased tolerance, the need for larger and larger doses of a substance to get the desired effect, and symptoms of withdrawal when one discontinues the drug. • Review the list of drugs and their effects in Table 6.1.