ITP - Sleep and Consciousness PDF

ITP **Consciousness** describes our awareness of internal and external stimuli. **Awareness of internal stimuli** includes feeling pain, hunger, thirst, sleepiness, and being aware of our thoughts and emotions **Awareness of external stimuli** includes experiences such as seeing the light from th...

ITP **Consciousness** describes our awareness of internal and external stimuli. **Awareness of internal stimuli** includes feeling pain, hunger, thirst, sleepiness, and being aware of our thoughts and emotions **Awareness of external stimuli** includes experiences such as seeing the light from the sun, feeling the warmth of a room, and hearing the voice of a friend. **Sleep** is a state marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness. **Wakefulness** is characterized by high levels of sensory awareness, thought, and behavior **Biological rhythms** are internal rhythms of biological activity. A woman's menstrual cycle is an example of a biological rhythm---a recurring, cyclical pattern of bodily changes. **Circadian rhythm** is a biological rhythm that takes place over a period of about 24 hours. Our sleep-wake cycle, which is linked to our environment's natural light-dark cycle, is perhaps the most obvious example of a circadian rhythm, but we also have daily fluctuations in heart rate, blood pressure, blood sugar, and body temperature. **Homeostasis** is the tendency to maintain a balance, or optimal level, within a biological system. The brain's clock mechanism is located in an area of the hypothalamus known as the **suprachiasmatic nucleus (SCN).** One important regulator of sleep-wake cycles is the hormone **melatonin.** The **pineal gland,** an endocrine structure located inside the brain that releases melatonin, is thought to be involved in the regulation of various biological rhythms and of the immune system during sleep **Sleep regulation** refers to the brain's control of switching between sleep and wakefulness as well as coordinating this cycle with the outside world. **Jet lag** is a collection of symptoms that results from the mismatch between our internal circadian cycles and our environment. **Insomnia** (i.e., a consistent difficulty in falling or staying asleep for at least three nights a week over a month's time) **Rotating shift work** refers to a work schedule that changes from early to late on a daily or weekly basis. For example, a person may work from 7:00 a.m. to 3:00 p.m. on Monday, 3:00 a.m. to 11:00 a.m. on Tuesday, and 11:00 a.m. to 7:00 p.m. on Wednesday. In such instances, the individual's schedule changes so frequently that it becomes difficult for a normal circadian rhythm to be maintained. When people have difficulty getting sleep due to their work or the demands of day-to-day life, they accumulate a **sleep debt**. A person with a sleep debt does not get sufficient sleep on a chronic basis. **Sleep rebound** refers to the fact that a sleep-deprived individual will fall asleep more quickly during subsequent opportunities for sleep. **Sleep** is characterized by certain patterns of activity of the brain that can be visualized using **electroencephalography (EEG),** and different phases of sleep can be differentiated using EEG as well. **Evolutionary psychology** is a discipline that studies how universal patterns of behavior and cognitive processes have evolved over time as a result of natural selection. Sleep is composed of several different stages that can be differentiated from one another by the patterns of **brain wave** activity that occur during each stage. Our brain wave activity is dominated by **beta waves**. As compared to the brain wave patterns while asleep, beta waves have the **highest frequency** **Rapid eye movement (REM)** sleep is characterized by darting movements of the eyes under closed eyelids. Brain waves during REM sleep appear very similar to brain waves during wakefulness. **Non-REM (NREM)** sleep is subdivided into three stages distinguished from each other and from wakefulness by characteristic patterns of brain waves. **Stages of Sleep** **Stage 1 sleep** is a *[transitional phase]* that occurs between wakefulness and sleep, the period during which we drift off to sleep. During this time, there is a slowdown in both the rates of respiration and heartbeat. The early portion of stage 1 sleep produces **alpha waves.** These patterns of electrical activity (waves) resemble that of someone who is very relaxed, yet awake, but they have less variability (are more synchronized) and are relatively lower in frequency (8--12 Hz) and higher in amplitude than beta waves **Theta waves** are even lower frequency (4--7 Hz), and higher in amplitude, than the alpha wave patterns. It is relatively easy to wake someone from stage 1 sleep; in fact, people often report that they have not been asleep if they are awoken during stage 1 sleep. **Stage 2 sleep**, the body goes into a *[state of deep relaxation.]* Theta waves still dominate the activity of the brain, but they are interrupted by brief bursts of activity known as **sleep spindles.** sleep spindle is a rapid burst of higher frequency brain waves that may be important for learning and memory A **K-complex** is a very high amplitude pattern of brain activity that may in some cases occur in response to environmental stimuli. Thus, K-complexes might serve as a bridge to higher levels of arousal in response to what is going on in our environments **REM stage 3 sleep** is often referred to as *[deep sleep or slow-wave]* sleep because this stage is characterized by low frequency (less than 3 Hz), high amplitude **delta waves** **Dreams** and their associated meanings vary across different cultures and periods of time. **Manifest content** is the actual content, or storyline, of a dream **Latent content**, on the other hand, refers to the hidden meaning of a dream **Collective unconscious**, as described by Jung, is a theoretical repository of information he believed to be shared by everyone. **Lucid dreams** are dreams in which certain aspects of wakefulness are maintained during a dream state. In a lucid dream, a person becomes aware of the fact that they are dreaming, and as such, they can control the dream's content **Insomnia,** a consistent difficulty in falling or staying asleep, is the most common of the sleep disorders. **Cognitive-behavioral therapy** is a type of psychotherapy that focuses on cognitive processes and problem behaviors. A **parasomnia** is one of a group of sleep disorders in which unwanted, disruptive motor activity and/or experiences during sleep play a role. **Sleepwalking,** or somnambulism, the sleeper engages in relatively complex behaviors ranging from wandering about to driving an automobile. During periods of sleepwalking, sleepers often have their eyes open, but they are not responsive to attempts to communicate with them. **REM sleep behavior disorder (RBD)** occurs when the muscle paralysis associated with the REM sleep phase does not occur. Individuals who suffer from RBD have high levels of physical activity during REM sleep, especially during disturbing dreams. These behaviors vary widely, but they can include kicking, punching, scratching, yelling, and behaving like an animal that has been frightened or attacked. This disorder is associated with a number of neurodegenerative diseases such as **Parkinson's disease.** **Clonazepam**, an anti-anxiety medication with sedative properties, is most often used to treat RBD. It is administered alone or in conjunction with doses of melatonin (the hormone secreted by the pineal gland). **Restless leg syndrome** has uncomfortable sensations in the legs during periods of inactivity or when trying to fall asleep. This discomfort is relieved by deliberately moving the legs, which, not surprisingly, contributes to difficulty in falling or staying asleep. **Night terrors** result in a sense of panic in the sufferer and are often accompanied by screams and attempts to escape from the immediate environment **Sleep apnea** is defined by episodes during which a sleeper's breathing stops. **Obstructive sleep apnea** occurs when an individual's airway becomes blocked during sleep, and air is prevented from entering the lungs. **Central sleep apnea**, disruption in signals sent from the brain that regulate breathing cause periods of interrupted breathing **Continuous positive airway pressure (CPAP)** device includes a mask that fits over the sleeper's nose and mouth, which is connected to a pump that pumps air into the person's airways, forcing them to remain open **Sudden infant death syndrome (SIDS)** an infant stops breathing during sleep and dies. a person with **narcolepsy** cannot resist falling asleep at inopportune times. These sleep episodes are often associated with **cataplexy**, which is a lack of muscle tone or muscle weakness, and in some cases involves complete paralysis of the voluntary muscles. This is similar to the kind of paralysis experienced by healthy individuals during REM sleep **Physical dependence** involves changes in normal bodily functions---the user will experience withdrawal from the drug upon cessation of use. **Psychological dependence** has an emotional, rather than physical, need for the drug and may use the drug to relieve psychological distress. **Tolerance** is linked to physiological dependence, and it occurs when a person requires more and more drug to achieve effects previously experienced at lower doses. Drug **withdrawa**l includes a variety of negative symptoms experienced when drug use is discontinued. **Depressant** is a drug that tends to suppress central nervous system activity. Other depressants include barbiturates and benzodiazepines. These drugs share in common their ability to serve as agonists of the gamma-Aminobutyric acid (GABA) neurotransmitter system. **Stimulants** are drugs that tend to increase overall levels of neural activity. Many of these drugs act as agonists of the dopamine neurotransmitter system. **Methamphetamine** is a type of amphetamine that can be made from ingredients that are readily available (e.g., medications containing pseudoephedrine, a compound found in many over-the-counter cold and flu remedies). Stimulant users seek **a euphoric high**, feelings of intense elation and pleasure, especially in those users who take the drug via intravenous injection or smoking **Opioid** is one of a category of drugs that includes heroin, morphine, methadone, and codeine. Opioids have analgesic properties; that is, they decrease pain. Natural opioids, called **opiates,** are derivatives of opium, which is a naturally occurring compound found in the poppy plant. **Methadone** is a synthetic opioid that is less euphorigenic than heroin and similar drugs. **Methadone clinics** help people who previously struggled with opioid addiction manage withdrawal symptoms through the use of methadone. **Codeine** is an opioid with relatively low potency. It is often prescribed for minor pain, and it is available overthe-counter in some other countries. Like all opioids, codeine does have abuse potential. In fact, abuse of prescription opioid medications is becoming a major concern worldwide **Hallucinogen** is one of a class of drugs that results in profound alterations in sensory and perceptual experiences **Hypnosis** is a state of extreme self-focus and attention in which minimal attention is given to external stimuli. In the therapeutic setting, a clinician may use relaxation and suggestion in an attempt to alter the thoughts and perceptions of a patient. **Meditation** is the act of focusing on a single target (such as the breath or a repeated sound) to increase awareness of the moment. While hypnosis is generally achieved through the interaction of a therapist and the person being treated, an individual can perform meditation alone. Often, however, people wishing to learn to meditate receive some training in techniques to achieve a meditative state. **Chap 5-Sense and Percept** Sensory receptors are specialized neurons that respond to specific types of stimuli. When sensory information is detected by a sensory receptor, **sensation** has occurred. These cells relay messages, in the form of action potentials (as you learned when studying biopsychology), to the central nervous system. The conversion from sensory stimulus energy *[to action potential]* is known as **transduction.** **Absolute threshold** refers to the minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time It is also possible for us to get messages that are presented below the threshold for conscious awareness---these are called **subliminal messages** how much difference in stimuli is required to detect a difference between them. This is known as the **just noticeable difference (jnd) or difference threshold.** **Perception** refers to the way sensory information is organized, interpreted, and consciously experienced. **Bottom-up processing** refers to sensory information from a stimulus in the environment driving a process **top-down processing** refers to knowledge and expectancy driving a process We often don't perceive stimuli that remain relatively constant over prolonged periods of time. This is known as **sensory adaptation.** **Inattentional blindness** is the failure to notice something that is completely visible because the person was actively attending to something else and did not pay attention to other things The ability to identify a stimulus when it is embedded in a distracting background is called **signal detection theory.** **Amplitude** of a wave is the distance from the center line to the top point of the crest or the bottom point of the trough. **Wavelength** refers to the length of a wave from one peak to the next. **Frequency** refers to the number of waves that pass a given point in a given time period and is often expressed in terms of hertz (Hz), The **visible spectrum** is the portion of the larger **electromagnetic spectrum** that we can see The **cornea** is the transparent covering over the eye. It serves as a barrier between the inner eye and the outside world, and it is involved in focusing light waves that enter the eye. **Pupil** is the small opening in the eye through which light passes, and the size of the pupil can change as a function of light levels as well as emotional arousal. The pupil's size is controlled by muscles that are connected to **the iris**, which is the colored portion of the eye. light crosses the **lens,** a curved, transparent structure that serves to provide additional focus. These photoreceptor cells, known as cones, are light-detecting cells. The cones are specialized types of photoreceptors that work best in bright light conditions. **Cones** are very sensitive to acute detail and provide tremendous spatial resolution. They also are directly involved in our ability to perceive color. **Rods** are specialized photoreceptors that work well in low light conditions, and while they lack the spatial resolution and color function of the cones, they are involved in our vision in dimly lit environments as well as in our perception of movement on the periphery of our visual field. **trichromatic theory of color vision,** shown in Figure 5.14, all colors in the spectrum can be produced by combining red, green, and blue. The three types of cones are each receptive to one of the colors. **Opponent-process theory**. According to this theory, color is coded in opponent pairs: black-white, yellowblue, and green-red. An **afterimage** describes the continuation of a visual sensation after removal of the stimulus. For example, when you stare briefly at the sun and then look away from it, you may still perceive a spot of light although the stimulus (the sun) has been removed. Our ability to perceive spatial relationships in three-dimensional (3-D) space is known as **depth perception**. With depth perception, we can describe things as being in front, behind, above, below, or to the side of other things. We use a variety of cues in a visual scene to establish our sense of depth. Some of these are **binocular cues,** which means that they rely on the use of both eyes. **Monocular cues,** or cues that require only one eye. **Linear perspective** refers to the fact that we perceive depth when we see two parallel lines that seem to converge in an image The **temporal theory of pitch perception** asserts that frequency is coded by the activity level of a sensory neuron. This would mean that a given hair cell would fire action potentials related to the frequency of the sound wave. The **place theory of pitch perception** suggests that different portions of the basilar membrane are sensitive to sounds of different frequencies. **monaural** (one-eared) and **binaural** (two-eared) cues to localize sound. **Interaural level difference** refers to the fact that a sound coming from the right side of your body is more intense at your right ear than at your left ear because of the attenuation of the sound wave as it passes through your head. **Deafness** is the partial or complete inability to hear. Some people are born without hearing, which is known as **congenital deafness.** When the hearing problem is associated with a failure to transmit neural signals from the cochlea to the brain, it is called **sensorineural hearing loss.** One disease that results in sensorineural hearing loss is **Ménière\'s disease** **Vertigo** (a sense of spinning), and an increase in pressure within the inner ear **Cochlear implants** are electronic devices that consist of a microphone, a speech processor, and an electrode array. **Olfactory receptor** cells are located in a mucous membrane at the top of the nose. Small hair-like extensions from these receptors serve as the sites for odor molecules dissolved in the mucus to interact with chemical receptors located on these extensions Once an odor molecule has bound a given receptor, chemical changes within the cell result in signals being sent to the **olfactory bulb**: a bulb-like structure at the tip of the frontal lobe where the olfactory nerves begin. Many species respond to chemical messages, known as **pheromones** **thermoception** (temperature perception) and **nociception** (a signal indicating potential harm and maybe pain) Pain that signals some type of tissue damage is known as **inflammatory pain.** This very rare genetic disorder is known as **congenital insensitivity** to pain (or congenital analgesia) **Vestibular sense** contributes to our ability to maintain balance and body posture **Proprioception** (perception of body position) **Kinesthesia** (perception of the body's movement through space) perception involved more than simply combining sensory stimuli. This belief led to a new movement within the field of psychology known as **Gestalt psychology** **figure-ground relationship**. According to this principle, we tend to segment our visual world into figure and ground. Figure is the object or person that is the focus of the visual field, while the ground is the background. Principle of **similarity** to group things in our visual fields. According to this principle, things that are alike tend to be grouped together Gestalt principles are the law of **continuity** (or good continuation) and closure. The law of **continuity** suggests that we are more likely to perceive continuous, smooth flowing lines rather than jagged, broken lines. principle of **closure** states that we organize our perceptions into complete objects rather than as a series of parts **Pattern perception**, or our ability to discriminate among different figures and shapes, occurs by following the principles described above. **Perceptual hypotheses:** educated guesses that we make while interpreting sensory information.