18.4 Chapter 4: Consciousness

show what you know

1. subjective
2. b. automatic processing
3. Answers will vary. The ability to focus awareness on a small segment of information that is available through our sensory systems is called selective attention. Although we are exposed to many different stimuli at once, we tend to pay particular attention to abrupt or unexpected changes in the environment. Such events may pose a danger and we need to be aware of them. However, selective attention can cause us to be blind to objects directly in our line of vision. This “looking without seeing” can have serious consequences, as we fail to see important occurrences in our surroundings. Our advice would be to try to remain aware of the possibility of inattentional blindness, in particular when you are in situations that could involve serious injury.

1. d. retinal ganglion cells.
2. b. Stage 2
3. cataplexy
4. Drawings will vary; see Infographic 4.2. A normal adult sleeper begins in non-rapid eye movement sleep. Stage 1, the lightest sleep, is associated with theta waves. Stage 2 includes evidence of sleep spindles. Stages 3 and 4 are associated with delta waves and deep sleep. Sleep then becomes less deep as the sleeper works back from Stage 4 to Stage 1. But instead of waking up, the sleeper enters rapid eye movement sleep (REM). Each cycle lasts about 90 minutes, with the average adult sleeper looping through five cycles per night.

1. manifest content; latent content
2. c. activation–synthesis model
3. Electroencephalogram (EEG) and PET scan technologies can demonstrate neural activity of the sleeping brain. During REM sleep, the motor areas of the brain are inhibited, but a great deal of neural activity is occurring in the sensory areas of the brain. The activation–synthesis model suggests dreams result when the brain responds to this random neural activity as if it has meaning. The creative human mind makes up stories to match the neural activity. The vestibular system is also active during REM sleep, resulting in sensations of floating or flying. The neurocognitive theory of dreams proposes that a network of neurons in the brain (including some areas in the limbic system and forebrain) are necessary for dreaming to occur.
4. a. until children are around 13 to 15 years old, their reported dreams are less vivid.

1. depressant: b. slows down activity in the CNS; 2. opioid: a. blocks pain; 3. alcohol: d. cirrhosis of the liver; 4. cocaine: c. increases neural activity in the CNS
2. c. LSD
3. psychoactive drugs
4. To determine if behaviors should be considered problematic, one could evaluate the presence of tolerance or withdrawal, both signs of physiological dependence. With tolerance, one’s system adapts to a drug over time and therefore needs more and more of the substance to re-create the original effect. Withdrawal can occur with constant use of some psychoactive drugs, when the body has become dependent and then reacts when the drug is withheld. In some cases, with psychological dependence, behaviors may be problematic when there is a strong desire or need to continue the behavior, but with no evidence of tolerance or withdrawal symptoms. If an individual harms himself or others around him as a result of his behaviors, it is a problem. Overuse is maladaptive and causes significant impairment or distress to the user and/or his family. This might include difficulties at work or school, neglect of children and household duties, and physically dangerous behaviors.

1. d. consciousness
2. b. selective attention.
3. a. The cocktail-party effect
4. d. circadian rhythm.
5. c. hypothalamus; reticular formation
6. a. insomnia
7. b. alpha
8. d. REM sleep
9. a. REM rebound.
10. b. wish fulfillment.
11. d. the neurocognitive theory
12. c. Psychoactive drugs
13. a. dopamine
14. b. tobacco
15. c. Physiological; withdrawal
16. Answers will vary. If someone walks into your room while you are asleep, you wake up immediately if there is a noise. You hear a text message come in during the night and immediately wake up to answer the message.
17. Without one’s 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, and is important because our sensory systems absorb large amounts of information that need to be processed. But it would not be possible to be consciously aware of all of it. Automatic processing also enables sensory adaption, which is the tendency to become less sensitive to and less aware of constant stimuli after a period of time.
18. We might not want a doctor with such a schedule to care for us because staying up for 48 hours can result in problems with memory, attention, reaction time, and decision making, all important processes that doctors use in caring for patients. Sleep deprivation impairs the ability to focus attention on a single activity, such as delivering medical care.
19. Answers will vary. See TABLE 4.1 for information on sleep disturbances and their defining characteristics.
20. Answers will vary. There are many different drugs that people use legally on an everyday basis. Caffeine is a psychoactive drug found in coffee, soda, tea, and some medicines. Over-the-counter pain-killers are legal drugs used to treat minor aches and pains. Nicotine is a highly addictive drug found in cigarettes or cigars. Alcohol is a legal psychoactive drug used on a daily basis by many people, as they drink a glass of wine or beer with an evening meal.

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ANSWER: Answers will vary. Conduct a study using a representative sample of U.S. college students. Because the goal of the study is to determine if the college living environment has some effect on sleep–wake cycles, the independent variable is living environment, and the dependent variable is sleep–wake cycle. The control group lives in a typical college dormitory, where there are no rules about when to go to sleep and wake up. The experimental group also lives in a dormitory, but this dorm has an early curfew and an 11 p.m. “lights-out” policy. At the end of some specified time period (for example, 6 weeks), the researchers observe and compare the sleep cycles of the two groups.