Week 7 Summary - Brain and Behaviour PDF

WEEK 7 SUMMARY Weekly Objective 1: Describe the core characteristics of the hypnotic state Hypnosis is defined as an altered state of consciousness brought on by special techniques and characterised by responsiveness to suggestions to produce changes in an individual’s experience and behaviour. Hypn...

WEEK 7 SUMMARY Weekly Objective 1: Describe the core characteristics of the hypnotic state Hypnosis is defined as an altered state of consciousness brought on by special techniques and characterised by responsiveness to suggestions to produce changes in an individual’s experience and behaviour. Hypnotised people are not sleeping. You cannot be hypnotised unwillingly, and the more people want to cooperate with the hypnotist, the more likely it is that they will experience hypnosis. Weekly Objective 2: Explain the factors that make someone more susceptible to hypnosis and hypnotic suggestibility Experiencing Hypnosis Procedures for inducing hypnosis begins with suggestions of relaxation and focusing people’s attention on a restricted, often monotonous, set of stimuli while asking them to ignore everything else as they imagine certain feelings. People with higher levels of hypnotic susceptibility have differences in certain brain structures, are more imaginative, tend to fantasise, tend to be more suggestible, have a greater ability to focus attention, can ignore distraction, can process information quickly and effortlessly, and have more positive attitudes and expectations about hypnosis. About 10 per cent of adults are difficult or impossible to hypnotise. The most important factor in inducing hypnosis is the willingness to be hypnotised. Under hypnosis, people respond to suggestions and can display age regression, apparently recalling or re-enacting their childhoods. Instructions about behaviour to take place after hypnosis has ended are called posthypnotic suggestions and can last for hours or days. Some people show posthypnotic amnesia, which is an inability to remember what happened under hypnosis. Hilgard described five main changes that people display during hypnosis. Hypnotised people display 1. reduced planfulness, the ability to initiate action on their own, 2. redistributed attention, they ignore all but the hypnotist, 3. increased ability to fantasise, 4. increased role taking, and 5. reduced reality testing. Weekly Objective 3: Describe the two main theories of how hypnosis works (role/sociocognitive theory, dissociation theory) According to state theories of hypnosis, hypnotised people experience an altered state of consciousness. According to non-state theories of hypnosis, like role theory, people under hypnosis merely act in accordance with the hypnotised role. They are not in a special state; they simply comply with the hypnotist’s directions. According to dissociation theory, which is a blend of role and state theories, hypnotised people are not in a special, but rather a general state of consciousness in which a person dissociates, or splits, various aspects of their behaviour and perceptions from the ‘self’ that normally controls these functions. Relaxation of this central control occurs as part of a social agreement to share control with the hypnotist. Weekly Objective 4: Explain how psychoactive substances affect the brain to create an altered state of consciousness Psychoactive drugs affect the brain, changing consciousness and other psychological processes. Psychopharmacology is the study of psychoactive drugs. Psychopharmacology Most psychoactive drugs or substances affect the brain by influence the interaction between neurotransmitters and receptors. These drugs get into the brain through the blood supply when they pass the blood-brain barrier. · Drugs that act as agonists mimic the effects of neurotransmitters. · Drugs acting as antagonists prevent neurotransmitters from binding with receptors and inhibit neurotransmitter activity. · Other drugs work by increasing or decreasing the release of a specific neurotransmitter. · And still others work by speeding or slowing the removal of a neurotransmitter from synapses. The Varying Effects of Drugs Predicting a drug’s effects is complicated because most psychoactive drugs interact with many neurotransmitter systems. Drugs have desirable main effects, but many also have undesirable side effects. Drug Abuse Drug abuse (or substance abuse) is the pattern of use that causes impairment or distress and serious social, legal, or interpersonal problems for the user. · Psychological dependence occurs when a person continues to use the drug to gain a sense of wellbeing, and becomes preoccupied with obtaining the drug, even when the drug produces adverse consequences. However, the person can still function without the drug. Psychological dependence can occur with and without physical dependence. · Physical dependence or addiction is a physiological state in which continued use of the drug is required to prevent the onset of an unpleasant drug withdrawal (or withdrawal syndrome). Drug tolerance is a condition in which increasingly large drug doses are needed to produce the same effect. It may develop with prolonged use of a drug. · By affecting the regulation of dopamine and other neurotransmitters in the brain’s ‘pleasure centres’, drugs of dependence have the capacity to create tremendously rewarding effects in most people. The changes created in the brain by drug dependence can remain long after drug use ends, increasing the chance for relapse months or even years later. Weekly Objective 5: Explain the role of expectations in enhancing the physiological effects of drugs Drug effects are not determined by biochemistry alone. Learned expectations also play a role. People who think they have taken a drug, but really haven’t may display the effects of the drug because they expect to be affected by it. Learned expectations regarding drug effects vary from culture to culture, therefore the effects of drugs likewise vary from culture to culture. Weekly Objective 6: Describe the three main classes of psychoactive substances and the specific drugs that each class encompasses. CNS Depressant Drugs CNS depressant drugs reduce central nervous system activity, partly by affecting the neurotransmitter GABA. Alcohol Alcohol affects the neurotransmitters dopamine, endorphins, endocannabinoids, glutamate, serotonin, and GABA. Alcohol affects specific brain regions. It reduces activity in the locus coeruleus and suppresses the hippocampus, cerebellum, and hindbrain mechanisms. Biological effects depend on the amount of alcohol the blood carries to the brain. Effects increase with faster drinking or drinking on an empty stomach, which speed the absorption of alcohol into the blood. Men tolerate higher amounts of alcohol than women. There are no effective measures to prevent or relieve the unpleasant hangover effects of overindulgence. Genetics also plays a role in determining the biochemical effects of alcohol and influences people’s tendency toward alcohol dependency. Barbiturates Also called downers or sleeping pills, barbiturates work by stimulating GABA receptors. Barbiturates are extremely addictive. Small doses cause relaxation, some euphoria, and diminished attention, among other effects. Higher doses cause deep sleep but can distort normal sleep patterns. Overdoses can be fatal and withdrawal symptoms some of the most unpleasant of any class of drug. GHB Gamma hydroxybutyrate or GHB is a naturally occurring substance like the neurotransmitter GABA. A laboratory-manufactured version of GHB (also known as ‘G’) has become a popular recreational drug. It is known for inducing relaxation, elation, loss of inhibition, suggestibility, and increased sex drive. It can cause severe negative reactions, especially when combined with other drugs. CNS Stimulating Drugs CNS stimulating drugs increase central nervous system activity. Amphetamines Commonly known as uppers or speed, amphetamines increase norepinephrine and dopamine activity and decrease GABA activity. Amphetamines stimulate the brain and sympathetic nervous system, increasing alertness, raising heart rate, arousal, supressing appetite, raising the blood pressure, and constricting blood vessels. Continued use can result in a variety of mental, including long term psychiatric conditions and physical problems. Cocaine Cocaine’s effects are like but more rapid than those of amphetamines. Additionally, the effects of cocaine are short-lived, which may help explain why this drug is especially addictive both psychologically and physiologically, particularly crack, a purified, highly potent form of cocaine. Cocaine stimulates self-confidence and optimism. Continued use results in a variety of mental and physical problems and overdoses can be deadly. Ceasing cocaine dependence can be difficult. Numerous pharmacological and psychological treatments have been tried with mixed results, particularly over the long term. Caffeine Caffeine is the world’s most popular drug. This drug reduces drowsiness and can enhance cognitive performance and vigilance. It improves problem-solving, increases physical work capacity, and raises urine production. Long term caffeine can cause physical dependence and associated withdrawal symptoms. Nicotine This drug stimulates the autonomic nervous system. It enhances the action of the neurotransmitter acetylcholine, increases the release of glutamate, activates the dopaminerelated pleasure system, and stimulates endogenous cannabinoid and opioid systems. It can improve mood, memory, and attention. Regular nicotine use can cause psychological and/or physiological dependence. Smoking is a major risk factor for cancer, heart disease and respiratory disorders. MDMA Also called ‘ecstasy’, MDMA increases the activity of dopamine neurons and is a serotonin agonist. It leads to some of the same effects as those produced by cocaine and amphetamines. With continued use, MDMA’s positive effects decrease, but its negative effects persist. Although MDMA does not appear to be physically addictive, high frequency use can cause permanent brain damage and cognitive impairment. Opiates Opiates, which include opium, morphine, heroin, codeine, oxycodone, hydrocodone, and propoxyphene are unique in induce states of sleep and pain relief. Opiates depress activity in wide areas of the cerebral cortex, they act as agonists for endorphins, and they appear to stimulate the endocannabinoid system, which may explain their euphoric effects. They are highly addictive partly because they stimulate a type of glutamate receptor that can physically change a neuron’s structure. Hallucinogenic Drugs Hallucinogenic drugs, also called psychedelics or psychotomimetics, cause a loss of contact with reality and induce changes in emotion, perception, and thought. Lysergic acid diethylamide (LSD) is one of the most powerful psychedelics, however the effects are largely unpredictable. LSD stimulates serotonin receptors in the forebrain. Unpleasant hallucinations and delusions can occur unpredictably. LSD is not addictive, but tolerance does develop. It can cause paranoia, panic attacks and flashbacks. Ketamine Veterinarians use ketamine as an anaesthetic and doctors use it for critically ill patients or for suppressing dangerous seizure activity. People steal it to use as a recreational drug called ‘Special K’. It causes dissociative feelings that people describe as an ‘out of body’ experience, but it causes memory damage. Marijuana The active ingredient in the hemp plant Cannabis sativa is tetrahydrocannabinol (THC). THC alters the blood flow to many brain regions. Low doses cause restlessness and hilarity, followed by carefree relaxation, vivid sensations, and food cravings. THC collects in the brain and reproductive organs. The brain contains several receptors for THC and produces a number of natural ‘endogenous cannabinoids’ whose receptors respond to THC.