Discovering Psychology Special Update For DSM-5 Don H. Hockenbury and Sandra E. Hockenbury Discovering Psychology Sixth Edition Special Update For DSM-5 Chapter 4 Consciousness and Its Variations Copyright © 2014 by Worth Publishers
Figure 4.1 (a) Can We Read Your Mind? We’d like you to participate in a mind-reading experiment. Please follow all directions as carefully as you can. First, pick one of the six cards below and remember it. Figure 4.1 (a) Can We Read Your Mind? Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Table 4.1 Examples of Human Circadian Rhythms Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Figure 4.1 (b) Can We Read Your Mind? Take a close look. Is your card missing? If so, we correctly identified the card you chose! Did we successfully read your mind? Figure 4.1 (b) Can We Read Your Mind? Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Figure 4.2 The Biological Clock Special photoreceptors in the retina regulate the effects of light on the body’s circadian rhythms (Menaker, 2003). In response to morning light, signals from these special photoreceptors are relayed via the optic nerve to the suprachiasmatic nucleus. In turn, the suprachiasmatic nucleus reduces the pineal gland’s production of melatonin, a hormone that causes sleepiness. As blood levels of melatonin decrease, mental alertness increases. Daily exposure to bright light, especially sunlight, helps keep the body’s circadian rhythms synchronized and operating on a 24-hour schedule. Figure 4.2 The Biological Clock Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Figure 4.3 The First 90 Minutes of Sleep From wakefulness to the deepest sleep of stage 4 NREM, the brain’s activity, measured by EEG recordings, progressively diminishes, as demonstrated by larger and slower brain waves. The four NREM stages occupy the first 50 to 70 minutes of sleep. Then, in a matter of minutes, the brain cycles back to smaller, faster brain waves, and the sleeper experiences the night’s first episode of dreaming REM sleep, which lasts 5 to 15 minutes. During the rest of the night, the sleeper continues to experience 90-minute cycles of alternating NREM and REM sleep. Figure 4.3 The First 90 Minutes of Sleep Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Figure 4.4 The 90-Minute Cycles of Sleep During a typical night, you experience five 90-minute cycles of alternating NREM and REM sleep. The deepest stages of NREM sleep, stages 3 and 4, occur during the first two 90-minute cycles. Dreaming REM sleep episodes become progressively longer as the night goes on. Shifts in sleep position, indicated by the dots, usually occur immediately before and after REM episodes. Figure 4.4 The 90-Minute Cycles of Sleep Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Figure 4.5 Sleep Over the Lifespan Sleep quality changes significantly over the lifespan. In particular, notice that slow-wave sleep decreases over the lifespan, as does total sleep time. By middle adulthood, people are more likely to experience wakefulness after sleep onset, abbreviated WASO. Senior adults aged 55 and older often take longer to fall asleep, which is technically called sleep latency (Bootzin & Epstein, 2011). Figure 4.5 Sleep Over the Lifespan Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Figure 4.6 The Activation–Synthesis Model of Dreaming According to the activation–synthesis model of dreaming, dreaming is our subjective awareness of the brain’s internally generated signals during sleep. Dreaming is initiated when brainstem circuits arouse brain areas involved in emotions, memories, movements, and sensations. These activated brain areas, shown in green, give rise to dreaming consciousness and the dream imaginations of sensations, perceptions, movements, and feelings. The activated brain synthesizes, or combines, these elements, drawing on previous experiences and memories to impose a personal meaning on the dream story (Hobson, 2005; McCarley, 2007). Other brain areas, highlighted in purple, are deactivated or blocked during dreaming. Outgoing motor signals and incoming sensory signals are blocked, keeping the dreamer from acting out the dream or responding to external stimuli (Pace-Schott, 2005). The logical, rational, and planning functions of the prefrontal cortex are suspended. Hence, dream stories can evolve in ways that seem disjointed or illogical. And because the prefrontal cortex is involved in processing memories, most nightly dream productions evaporate with no lingering memories of having had these experiences (Muzur & others, 2002). Figure 4.6 The Activation–Synthesis Model of Dreaming Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Table 4.2 Help Through Hypnosis Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Table 4.3 Behavioral Effects of Blood Alcohol Levels Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Table 4.4 Common Sources of Caffeine Don H. Hockenbury and Sandra E. Hockenbury: Discovering Psychology, Sixth Edition – Special Update For DSM-5 Copyright © 2014 by Worth Publishers
Photo Credits Slide 5: Image Source/ Punchstock Slide 9: Corbis