Chapter 4 States of Consciousness

Chapter 4: States of consciousness What is consciousness? (4.1) - Consciousness- awareness of internal and external stimuli such as feelings of hunger - and pain or detection of light Wakefulness- high levels of sensory awareness, thought, and behavior Sleep- low levels of physical activity and reduced sensory awareness Biological rhythms - - Biological rhythm- an internal cycle of biological activity including: - Fluctuation of body temperature - An individual's menstrual cycle - Levels of alertness Circadian rhythm- a biological rhythm that occurs approximately 24 hours Generated by the Suprachiasmatic nucleus (SCN) The sleep wake cycle is linked to our environments natural light dark cycle What controls our biological rhythm? - The hypothalamus Melatonin and sleep regulation - Our sleep-wake cycle is also regulated by other factors such as the hormone melatonin Melatonin release is stimulated by darkness, making us sleepy, and inhibited by daylight Released by the pineal gland Sleep regulation- the brains control of switching between sleep and wakefulness Disruption of normal sleep - Certain circumstances can throw off our circadian rhythm Jet lag- symptoms resulting from the mismatch between our internal circadian cycles and our environment Symptoms can include fatigue, sluggishness, irritability and insomnia Rotating shift work- a work schedule that changes from early to late on a daily/weekly basis Can result in persistent feelings of exhaustion and agitation, sleeping problems can lead to signs of depression and anxiety Sleep deprivation - Sleep rebound- a sleep deprived individual will tend to take a shorter time to fall asleep during subsequent opportunities for sleep Sleep debt- result of insufficient sleep on a chronic basis What is sleep (4.2) - Sleep is a state marked by relatively low physical activity and is reduced sense of awareness Sleep is associated with the following the secretion and regulation of many hormones including: - Melatonin - Follicle stimulating hormone - Luteinizing hormone - Growth hormone Why do we sleep - Adaptive function (evolutionary hypothesis) 1. Sleep is essential to restore resources that are expended during the day 2. Sleep is an adaptive response to predatory risks, which increase in darkness There is little evidence to support these explanations Cognitive function Focuses on sleeps importance for cognitive function and memory formation Sleep deprivation results in disruptions in cognition and memory deficits These impairments become more severe as the amount of sleep deprivation increases Slow wave sleep appears to be essential for effective memory formation Stages of sleep (4.3) Brainwaves during sleep - Brain wave activity changes dramatically across the different stages of sleep Alpha- relatively low frequency, relatively high amplitude, synchronized Theta- low frequency, moderately low amplitude Delta- low frequency, high amplitude, desynchronized NREM sleep: stages 1 and 2 - - - Stage 1 - Traditional phase occurring between wakefulness and sleep - Rates of respiration and heartbeat slow down Stage 2 - The body goes into deep relaxation - Characterized by the appearance of both sleep spindles and K-complexes Sleep spindles- rapid burst of high frequency brainwaves K-complexes- very high amplitude pattern of brain activity NREM sleep: stage 3 - Known as slow wave sleep Respiration and heart rate slow down further Rapid eye movement (REM) sleep - Rapid eye movements - Paralysis of voluntary muscles Brain waves are similar to those seen during wakefulness REM rebound Dreams - - - Sigmund freud: -Saw dreams as a way to gain access to the unconscious Manifest content- the actual content of the dream Latent content- the hidden meaning of the dream Carl Jung: believed that certain symbols in dreams reflected universal archetypes regardless of culture or location. Believed that certain symbols in dreams reflected universal archetypes regardless of culture or location. Cartwright & Hibson: Dreams may represent life events that are important to the dreamer. Dreaming may represent a state of protoconsciousness or a virtual reality Lucid dreams- certain aspects of wakefulness are maintained during a dreaming state *you realize that you are dreaming* Sleep problems and disorders (4.4) Insomnia - - Defined by difficulty of falling or staying asleep, for at least 3 nights a week, for at least one month Contributing factors include: -Age -Drug use -Exercise -Mental status -Bedtime routines Treatment: -Stress management techniques -Cognitive behavioral therapy, which focus on cognitive processes and problem behaviors Parasomnias - - Sleepwalking: - Sleeper engages in relatively complex behaviors that can range from wandering around the house Usually occurs during slow wave sleep - REM sleep behavior disorder: Occurs when the muscle paralysis associated with REM sleep does not occur Includes high levels of physical activity during REM sleep Often treated with clonazepam Resting leg syndrome: - -Involves uncomfortable sensations in the legs when trying to fall asleep that are relieved by moving the legs Can be treated with a variety of medications Night terrors: -Sleeper experiences a sense of panic and may scream or attempt to escape Sleep apnea - Occurs when individuals stop breathing during their sleep, usually for 10-20 seconds or longer 1. Obstructive- airway becomes blocked, and air is prevented from entering the lungs 2. Central- CNS fails to initiate breaths Treatment can include a continuous positive airway pressure (CPAP) device which pumps air into the persons airways Sudden infant death syndrome - Occurs when an infant stops breathing during sleep and dies Infants younger than 12 months are at the highest risk Contributing factors: - Premature birth -Smoking within the home -Hyperthermia Narcolepsy - Involves an irresistible urge to fall asleep during waking hours Shares many features of REM sleep including: Cataplexy- loss of muscle tone while awake or in some cases complete paralysis of the voluntary muscles Hypnagogic hallucinations- vivid, dream like hallucinations Treatment- psychomotor stimulant drugs Substance use and abuse (4.5): substance use disorder - Substance use disorder is a compulsive pattern of drug use despite negative consequences Physiological dependence- involves changes in normal bodily functions and withdrawal upon cessation of use Psychological dependence- emotional need for the drug Tolerance- occurs when a person requires more and more of a drug to achieve effects previously experienced at lower doses Withdrawal- negative symptoms experienced when drug use is discontinued Drug categories - Antipsychotics Stimulants Depressants