Summary of Concepts

Summary of Concepts

LO 1     Define consciousness.

Consciousness is the state of being aware of oneself, one’s thoughts, and/or the environment. There are various levels of conscious awareness, including wakefulness, sleepiness, drug-induced states, dreaming, hypnotic states, and meditative states, to name a few.

LO 2     Explain how automatic processing relates to consciousness.

Because our sensory systems absorb large amounts of information, being consciously aware of all of it is not possible. Without our awareness, the brain determines what is important, what requires immediate attention, and what can be processed and stored for later use if necessary. This automatic processing happens involuntarily, with little or no conscious effort.

LO 3     Describe how we narrow our focus on specific stimuli to attend to them.

We have access to a great deal of information in our internal and external environments, but we can only focus our attention on a small portion of that information. This narrow focus on specific stimuli is referred to as selective attention. We are designed to pay attention to changes in environmental stimuli, to unfamiliar stimuli, and to especially strong stimuli.

LO 4     Identify how circadian rhythm relates to sleep.

Predictable daily patterns influence our behaviors, alertness, and activity levels in a cyclical fashion. These daily patterns in our physiological functioning roughly follow the 24-hour cycle of daylight and darkness, driven by our circadian rhythm. In the circadian rhythm for sleep and wakefulness, there are two times when the desire for sleep hits hardest. The first occurs in the early hours of the morning, between about 2:00 to 6:00 a.m., and the second, less intense desire for sleep strikes mid-afternoon, around 2:00 or 3:00 p.m.

LO 5     Summarize the stages of sleep.

Sleep begins in non-rapid eye movement (non-REM), or nondreaming sleep, which has four stages. The lightest stage of sleep is Stage 1; it is the time during which hallucinations, or imaginary sensations, can occur. This stage lasts only a few minutes before Stage 2 sleep begins. At this point, it is a little more difficult to rouse the sleeper before she drifts even further into Stage 3 sleep and then Stage 4 sleep, slow-wave sleep. Stage 4 is the deepest sleep. As the night progresses, the sleeper goes back to Stage 1 from Stage 4. And instead of waking up, the sleeper enters a 5th stage of sleep known as rapid eye movement (REM) sleep. During this stage, closed eyes dart around, and brain activity changes. People awakened from REM sleep often report having vivid dreams. Each cycle, from Stage 1 to REM, lasts about 90 minutes, and the average adult loops through five complete cycles per night. These cycles change in composition throughout the night.

LO 6     Recognize various sleep disorders and their symptoms.

Narcolepsy is a neurological disorder characterized by excessive daytime sleepiness and other sleep-related disturbances. REM sleep behavior disorder is a disorder of sleep in which the mechanism responsible for paralyzing the body during REM sleep does not function properly. The individual is able to move around and act out dreams. Obstructive sleep apnea hypopnea is a serious disturbance of non-REM sleep characterized by the periodic blockage of breathing. It results in the upper throat muscles going limp, allowing the airway to close. The sleeper awakens and gasps for air, then drifts back to sleep. Insomnia is the inability to fall asleep or stay asleep. People with insomnia report on the poor quantity or quality of their sleep, and some may complain about waking up too early and being unable to fall back to sleep.

LO 7     Summarize the theories of why we dream.

Freud believed dreams have two levels of content. Manifest content, the apparent meaning of the dream, is the actual story line of the dream itself—what you remember when you wake up. Latent content contains the hidden meaning of the dream, which represents the unconscious conflicts and desires. The activation–synthesis model suggests that dreams have no meaning whatsoever: we respond to random neural activity of the brain during sleep as if it has meaning. Neurocognitive theory suggests there is a network of neurons in the brain necessary for dreaming to occur. According to this theory, dreams are the result of how sleep and consciousness have evolved in humans.

LO 8     Define psychoactive drugs.

Psychoactive drugs can cause changes in psychological activities such as sensation, perception, attention, judgment, memory, self-control, emotion, thinking, and behavior. These drugs alter consciousness in an untold number of ways. They can depress activity in the central nervous system, produce hallucinations, and cause a sense of euphoria.

LO 9     Identify several depressants and stimulants and know their effects.

Depressants decrease the activities in the central nervous system. These include barbiturates, opioids, and alcohol. Stimulants are drugs that increase neural activity in the central nervous system, producing effects such as heightened alertness and energy and an elevated mood. These include cocaine, amphetamines, methamphetamine, caffeine, and nicotine.

LO 10     Discuss some of the hallucinogens.

Hallucinogens are drugs that produce hallucinations, altered moods, and distorted perception and thought. The most well-known hallucinogen is lysergic acid diethylamide (LSD). This odorless, tasteless, and colorless substance often produces extreme changes in sensation and perception. In addition to the traditional hallucinogens, a number of “club drugs,” or synthetic “designer drugs,” are commonly used at parties, raves, and dance venues. The most popular is methylenedioxymethamphetamine (MDMA), which is chemically similar to the stimulant methamphetamine, producing a combination of stimulant and hallucinogen effects. The most widely used illegal (in most states) drug is marijuana, and at high doses, tetrahydracannabinol (THC) can induce mild euphoria and create intense sensory experiences.

LO 11     Explain how physiological and psychological dependence differ.

With constant use of some psychoactive drugs, a condition can develop in which the body becomes dependent on the drug. Signs of this physiological dependence include tolerance and withdrawal. Psychological dependence occurs without the evidence of tolerance or withdrawal symptoms, but is indicated by many other problematic symptoms. People with psychological dependence believe they need the drug because it increases their emotional or mental well-being. Physiological dependence is physical and has serious physical consequences. Psychological dependence is associated with beliefs and emotions.

LO 12     Describe hypnosis and explain how it works.

Hypnosis is an altered state of consciousness that can create changes in perceptions and behaviors, usually resulting from suggestions made by a hypnotist. Hypnosis is known to ease pain associated with childbirth and surgery, and can reduce the need for painkillers. One theory suggests that hypnotized people experience a “split” in awareness or consciousness. Others suggest hypnosis is a role-playing exercise.

key terms

TEST PREP: are you ready?