Consciousness. } This section covers: What it means to be conscious States of consciousness

Transcription

1 Consciousness } This section covers: What it means to be conscious States of consciousness

2 The Continuum of Consciousness } Consciousness refers to our awareness of external stimuli and our own internalmental and physiological processes. Dr. Rudolph s Definition: Self awareness within context.

3 Historical Perspectives on the Study of Consciousness } Consciousness has long been a favorite topic of study among psychologists. Recall that questions of consciousness were addressed by a variety of philosophical traditions. William James (1890) coined the term stream of consciousness Moving, seemingly unbroken flow of conscious awareness. Proponents of the psychodynamic tradition used the term consciousness to refer to aspects of the mind that could be retrieved voluntarily In contrast unconscious parts of the mind remain hidden to voluntary searches for information. Cognitive psychologists debate questions of consciousness E.g., Why does some information become conscious, while other information does not?

4 The Continuum of Consciousness } Fundamental Questions: What does it mean to to be conscious? Is consciousness uniquely human? What is the relationship between brain function and consciousness?

5 The Continuum of Consciousness } Most would agree that lower order organisms (e.g., bacteria) do not possess consciousness, but that humans do. Consciousness is adaptive: Emerged at some point in the course of evolution. Has provided survival advantages to successive generations (i.e., birth cohorts construed over time).

6 The Continuum of Consciousness } Animals show variations in states of awareness. While ducks sleep, one hemisphere of their brains can process visual information from an eye that remains open. Does this imply consciousness? Probably not.

7 The Continuum of Consciousness } The self-awareness aspect of consciousness might be the rarest of all among living things. Self Awareness: The capacity for introspection and the ability to recognize oneself as an individual separate from the environment and other individuals. Self-awareness is often exemplified in I statements. E.g., I am hungry E.g., I can t believe it s only Tuesday! Important: Self awareness is the hallmark of consciousness among humans!

8 The Continuum of Consciousness } Conscious states can be viewed as points along a continuum This continuum of refers to a wide range of experiences, for example: Awareness to Unawareness Which roughly maps onto: Controlled/Conscious to Automatic/Unconscious

9 The Continuum of Consciousness } Controlled Processes Activities that require full awareness, alertness, and concentration to reach some goal. High Awareness & Conscious Processes Focused attention required in controlled processes usually interferes with the execution of other ongoing activities. } Automatic Processes Activities that require little awareness, take minimal attention, and do not interfere with other ongoing activities. Low Awareness & Unconscious Processes E.g., Daydreaming Requires a low level of awareness Often occurs during automatic processes

10 States of Consciousness } While consciousness is understood along a continuum, we often think in terms of states of consciousness. Altered States Result from using any number of procedures to produce an awareness that differs from normal consciousness. E.g., meditation, sleep, psychoactive drugs, hypnosis, etc.

11 States of Consciousness } Unconsciousness Can result from disease, trauma (e.g., a blow to the head), or general medical anesthesia. KEY: Total lack of sensory awareness Complete loss of responsiveness to one s environment.

12 Meditation } A state of heightened awareness achieved by using attention to control one s mental processes

13 Meditation } EEG recordings during meditation show increased alpha wave activity Characteristic of an awake but relaxed state. Important: Suggests that meditative states are not unique state of consciousness! } More experienced practitioners (3+ years) show increased theta activity in PFC. Characteristic of lighter stages of sleep. Theta activity in PFC correlated with experience of positive emotions.

14 Meditation } FMRI studies suggest that meditation appears to result in physical changes in the brain. Meditation has been correlated with increased cortical thickness and increased gray matter in the brainstem. } Some correlational research studies suggest that there are long-term health benefits associated with regular meditation. Lower levels of stress hormones in the body Enhanced immune system functioning Improved cardiovascular health Reductions in chronic pain

15 Consciousness and the Brain } Certain brain structures are necessary, but not sufficient, for consciousness

16 Consciousness and the Brain } Consciousness requires complex interactions between areas of the cerebral cortex and the thalamus Thalamus lesions result in profound unconsciousness (i.e., brain death) } The reticular formation plays an active role in raising or lowering the thresholds of conscious awareness } Important: These structures enable consciousness, but they do not produce its content!

17 Consciousness and the Brain } Binding Problem: One of the challenges in the study of consciousness is how to explain how the brain forms a unified whole out of large quantities of information. Possible Explanation: Sensory information combines with past experience to produce expectations for a current situation. } The integration of sensory input and prior experience becomes part of the stream of consciousness. Good explanation for the gradual emergence of consciousness in the developing child.

18 Sleeping and Dreaming } This section covers: Circadian rhythms Sleep cycles and dreaming

19 Sleep & Dreaming } Some questions to consider: Are you a morning person or an evening person? If you were entirely free to plan your evening and had no commitments the next day, at what time would you choose to go to bed? You have to do 2 hours of physically hard work. If you were entirely free to plan your day, in which time period would you choose to do the work? You have a 2-hour test to take that you know will be mentally exhausting. If you were entirely free to choose, in which time period would you choose to take the test?

20 Sleeping and Dreaming } Sleep consists of five different stages that involve different levels of awareness, consciousness, responsiveness, and physiological arousal. } Dreaming is a unique state of consciousness in which we are asleep but experience a variety of visual, auditory, and tactile images, often connected, and often in color.

21 Circadian Rhythms } A circadian rhythm is a built-in cycle of physical processes in living beings. Circadian rhythms support the maintenance of homeostasis. e.g., core body temperature, alertness, hormone productions and other biological processes.

22 Circadian Rhythms } This sleep circadian rhythm is programmed by a structure in the hypothalamus called the suprachiasmatic nucleus (SCN). } SCN is like an internal clock Signals other brain areas when to be alert and when to sleep.

23 Circadian Rhythms } SCN is very responsive to light changes (i.e., takes cues from eyes Is it dark? Is it light? ). Light information helps the SCN direct the release of melatonin (sleep hormone). Light information & melatonin regulate your sleep circadian rhythm. } When circadian rhythms are out of sync, the effect can be quite disruptive. Jet Lag Shift Work Disorder

24 Circadian Rhythms

25 Stages of Sleep

26 Stages of Sleep } Using EEG sleep researchers have identified five stages of sleep. } When we are awake and alert, our brain emits beta waves. Beta brain waves are rapid, with a high number of cycles per second. } When we are awake yet relaxed, our brain emits alpha waves. Alpha waves are somewhat slower and less frequent than beta waves.

27 Stages of Sleep } Stage I sleep is a light sleep and is characterized by theta waves. Theta waves are slower and less frequent than beta or alpha waves. Breathing and heart rate slow down. You may experience sensations such as falling or floating. You can easily awaken from stage I sleep, which typically lasts from 1 to 7 minutes.

28 Stages of Sleep } Stage II sleep is characterized by sleep spindles and lasts approximately 20 minutes. Sleep spindles are a pattern of slower theta waves sporadically disrupted by bursts of electrical activity. Breathing, muscle tension, heart rate, and body temperature continue to decrease. You are clearly asleep and not easily awakened. } Stage II sleep spindles help us process both simple and complex motor skills that we have learned.

29 Stages of Sleep } Stages III and IV sleep are referred to as slowwave sleep. In stage III sleep, you begin showing delta brainwave patterns. Delta waves are large, slow brain waves.

30 Stages of Sleep } When a consistent pattern of delta waves emerges, you have entered stage IV sleep. Stage IV sleep is referred to as deep sleep. The body is extremely relaxed. Heart rate, respiration, body temperature, and blood flow to the brain are reduced. Growth hormone is secreted. } It is difficult to awaken people from deep sleep. When awakened, people may be disoriented or confused.

31 REM (Rapid-Eye-Movement) Sleep } After ~30 40 minutes of slow-wave sleep, your brain and body start to speed up again. You cycle back through the stages of NREM sleep and then enter REM (rapid-eye-movement) sleep. Your breathing rate increases, Your heart beats irregularly. Muscle tone significantly decreases Leaving the muscles extremely relaxed; essentially paralyzed. Quick, shifting movements of the eyes are noted. Hence the name REM

32 REM (Rapid-Eye-Movement) Sleep } REM sleep is intimately connected to dreaming. You can dream in some form in all sleep stages, dreams during REM sleep are more easily recalled. More than 80% of people awakened from REM sleep report dreaming.

33 REM (Rapid-Eye-Movement) Sleep } Purpose of REM sleep? Memory processing! REM-deprived = less likely to recall complex information learned earlier in the day. REM-deprived = difficulty concentrating when they awaken. REM sleep may facilitate the storage of memories as well as facilitate mental strategies (e.g., attention). REM appears to help us process recent emotional experiences.

34 REM (Rapid-Eye-Movement) Sleep

35 How Much Sleep Do We Need? } Age. The older we get, the less sleep we need. Babies require a lot of sleep, between 16 and 18 hours a day. Preschoolers require less sleep, about hours a day, typically including a midday nap. Teenagers and young adults need less sleep than children, but they still require 8 10 hours of sleep a night.

36 How Much Sleep Do We Need? } Lifestyle/Environment Our cultural beliefs, lifestyle habits, and bedroom environment also influence the amount of sleep that we need or get.

37 How Much Sleep Do We Need? } Genetics. Genes may play a role in the amount of sleep that each of us requires. E.g., Sleep patterns of identical twins compared to fraternal twins More similar sleep needs and sleep behaviors among identical twins.» Genetic component to our propensity to be either night owls or early birds.

38 How Much Sleep Do We Need?

39 The Nature of Dreams

40 Theories of Dreaming } Hobson s Activation Synthesis Model Dreaming is a consequence of the highly aroused brain during REM sleep Cortex attempts to create meaning out of these neural impulses by synthesizing them into familiar images/stories based on stored memories.

41 Sleep Disorders } Not everyone sleeps soundly. ~ million adults in the U.S/ experience a sleep disorder Disturbance in the normal pattern of sleep. Sleep disorders also affect approximately 25% to 40% of children and adolescents. Insomnia, Narcolepsy, Sleep Apnea, Restless Legs Syndrome, Sleepwalking, Night Terrors

42 Insomnia } Insomnia, the most commonly reported sleep disorder The inability to get to sleep and/or stay asleep. More than 1/3 of American adults report insomnia in the past 12 months.

43 Insomnia } Correlates of insomnia? Stress, change in sleep schedule, obesity, chronic pain, drug abuse, anxiety, depression. Can be treated medically using antianxiety or sedative medications or by taking over-the-counter medications to induce sleepiness. Long-term use of sleep drugs may lead to dependence and serious side effects Memory loss, fatigue, increased sleepiness.

44 Insomnia } Chronic insomnia is best treated with a combination of treatments (e.g., drugs, therapy, changing sleep environment, lifestyle changes) Several sleep guidelines have evolved from our study of how we sleep.

45 Insomnia } Establish a regular sleep wake cycle to work with your body s natural sleep rhythm. } Avoid long naps during waking hours. Naps can disrupt your sleep circadian rhythm. } Don t use your bed for anything other than sleeping.

46 Insomnia } Avoid sleeping pills, alcohol, cigarettes, and caffeine. These are all drugs that can interfere with your natural sleep cycle and disrupt REM sleep. } Exercise during the day can promote good sleep. However, avoid physical workouts within an hour of bedtime.

47 Insomnia } Turn off your cell phone and computer prior to sleeping. } Turn off the lights. Unnecessary light exposure, from the television, cell phone, LCD clock display, or a night light affects sleep quality. It increases Stage I sleep and decreases slowwave/deeper sleep stages.