Brain and Behavior and Drugs: 2 nd pt Chapter 3

1. Brain and Behavior and Drugs: 2nd ptChapter 3

2. Association Areas • Although small, well-defined regions within these lobes control muscle movement and receive information from the body senses, most of the cortex—its association areas—are free to process other information.

3. Association Areas • Association areas are NOT involved in primary motor or sensory functions. • They integrate and act on information processed by the sensory areas. • Are involved in higher mental functions, such as learning, remembering, thinking, and speaking. • Association areas are found in all four lobes. • Complex human abilities, such as memory and language, result from the intricate coordination of many brain areas.

4. Association Areas More intelligent animals have increased “uncommitted” or association areas of the cortex.

5. Language Aphasiais an impairment of language, usually caused by left hemisphere damage either to Broca’s area (impaired speaking) or to Wernicke’s area (impaired understanding).

6. Specialization & Integration Brain activity when hearing, seeing, and speaking words

7. The Brain’s Plasticity The brain is sculpted by our genes but also by our experiences. Plasticity refers to the brain’s ability to modify itself after some types of injury or illness. Research indicates that some neural tissue can reorganize in response to damage. When one brain area is damaged, others may in time take over some of its function. If you lose a finger, the sensory cortex that received its input will begin to receive input from the adjacent fingers, which become more sensitive.

8. The Brain’s Plasticity • Our brains are most plastic when we are young children. • Constraint-induced therapy rewires the brain by restraining a fully functioning limb and forcing use of the “bad hand” or the uncooperative leg. • Eventually, the therapy reprograms the brain, improving the dexterity of a brain-damaged child or even an adult stroke victim. • New evidence reveals that adult humans can also generate new brain cells. • Monkey brains illustrate neurogenesis by forming thousands of new neurons each day.

9. Our Divided Brain Our brain is divided into two hemispheres. The left hemisphere processes reading, writing, speaking, mathematics, and comprehension skills. In the 1960s, it was termed as the dominant brain.

10. Splitting the Brain A procedure in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them. Corpus Callosum Courtesy of Terence Williams, University of Iowa Martin M. Rother

11. Split Brain Patients With the corpus callosum severed, objects (apple) presented in the right visual field can be named. Objects (pencil) in the left visual field cannot.

12. Divided Consciousness

13. Try This! Try drawing one shape with your left hand and one with your right hand, simultaneously. BBC

14. Drugs: Affecting our own Consciousness • Dependence and Addiction • Psychoactive Drugs • Influences on Drug Use

15. Drugs and Consciousness Psychoactive Drug: A chemical substance that alters perceptions and mood (affects consciousness).

16. Dependence & Addiction Continued use of a psychoactive drug produces tolerance. With repeated exposure to a drug, the drug’s effect lessens. Thus it takes greater quantities to get the desired effect.

17. Withdrawal & Dependence • Withdrawal:Upon stopping use of a drug (after addiction), users may experience the undesirable effects of withdrawal. • Dependence: Absence of a drug may lead to a feeling of physical pain, intense cravings (physical dependence), and negative emotions (psychological dependence).

18. Psychoactive Drugs Psychoactive drugs are divided into three groups. • Depressants • Stimulants • Hallucinogens

19. Depressants Depressantsaredrugs that reduce neural activity and slow body functions. They include: • Alcohol • Barbiturates • Opiates

20. Depressants • Alcoholaffects motor skills, judgment, and memory…and increases aggressiveness while reducing self awareness. Daniel Hommer, NIAAA, NIH, HHS Moderate Alzheimer’s

21. Depressants 2. Barbiturates:Drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment. Nembutal, Seconal, and Amytal are some examples.

22. Depressants 3. Opiates:Opium and its derivatives (morphine and heroin) depress neural activity, temporarily lessening pain and anxiety. They are highly addictive. http://opioids.com/timeline

23. Stimulants Stimulants are drugs that excite neural activity and speed up body functions. Examples of stimulants are: • Caffeine • Nicotine • Cocaine • Ecstasy • Amphetamines • Methamphetamines

24. Caffeine & Nicotine Caffeine and nicotine increase heart and breathing rates and other autonomic functions to provide energy.

25. Cocaine Induces immediate euphoria followed by a crash. Crack, a form of cocaine, can be smoked. Other forms of cocaine can be sniffed or injected. http://www.ohsinc.com

26. Ecstasy A stimulant and mild hallucinogen. Produces a euphoric high and can damage serotonin-producing neurons, which results in a permanent deflation of mood and impairment of memory.

27. Methamphetamines • Highly Addictive • Triggers strong release of dopamine, norepinephrine, and serotonin

28. Hallucinogens Hallucinogensare psychedelic (mind-manifesting) drugs that distort perceptions and evoke sensory images in the absence of sensory input.

29. Hallucinogens • LSD:Powerfulhallucinogenic drug Serotonin agonist. • THC: Cannabinoid receptors are found in parts of the brain that influence pleasure, memory, concentrating, time perception and coordinated movement.

30. Marijuana Use The use of marijuana in teenagers is directly related to the “perceived risk” involved with the drug.

31. Influences on Drug Use The use of drugs is based on biological, psychological, and social-cultural influences.

32. Drugs & Other Therapies • Drug Therapies • Brain Stimulation • Psychosurgery • Therapeutic Life-Style Changes

33. The Biomedical Therapies These include physical, medicinal, and other forms of biological therapies. • Drug Therapies • Brain Stimulation • Psychosurgery

34. Drug Therapies Psychopharmacology is the study of drug effects on mind and behavior. With the advent of drugs, hospitalization in mental institutions has rapidly declined.

35. Drug Therapies Many patients are left homeless on the streets due to their inability to cope independently in society. Margaret Holloway aka The Shakespeare Lady

36. How Neurotransmitters Influence Us Serotonin pathways are involved with mood regulation.

37. Dopamine Pathways Dopamine pathways are involved with diseases such as schizophrenia and Parkinson’s disease.

38. Antipsychotic Drugs Classical antipsychotics [chlorpromazine (Thorazine)]: Remove a number of positive symptoms associated with schizophrenia such as agitation, delusions, and hallucinations. Atypical antipsychotics [clozapine (Clozaril)]: Remove negative symptoms associated with schizophrenia such as apathy, jumbled thoughts, concentration difficulties, and difficulties in interacting with others.

39. Atypical Antipsychotic Clozapine (Clozaril) blocks receptors for dopamine and serotonin to remove the negative symptoms of schizophrenia.

40. Antianxiety Drugs Antianxiety drugs (Xanax and Ativan) depress the central nervous system and reduce anxiety and tension by elevating the levels of the Gamma-aminobutyric acid (GABA) neurotransmitter.

41. Antidepressant Drugs Antidepressant drugs like Prozac, Zoloft, and Paxil are Selective Serotonin Reuptake Inhibitors (SSRIs) that improve the mood by elevating levels of serotonin by inhibiting reuptake.

42. Mood-Stabilizing Medications Lithium Carbonate, a common salt, has been used to stabilize manic episodes in bipolar disorders. It moderates the levels of norepinephrine and glutamate neurotransmitters.

43. Brain Stimulation Electroconvulsive Therapy (ECT) ECT is used for severely depressed patients who do not respond to drugs. The patient is anesthetized and given a muscle relaxant. Patients usually get a 100 volt shock that relieves them of depression.

44. Alternatives to ECT Repetitive Transcranial Magnetic Stimulation (rTMS) In rTMS, a pulsating magnetic coil is placed over prefrontal regions of the brain to treat depression with minimal side effects.

45. Psychosurgery Psychosurgery was very popular even in Neolithic times. Although used sparingly today, about 200 such operations do take place in the US alone. Lobotomy

46. Psychosurgery Used as a last resort in alleviating psychological disturbances. Psychosurgery is irreversible. Removal of brain tissue changes the mind. Lesions are made by radiation, thermo-coagulation, freezing or cutting.

47. Psychological Disorders are Biopsychosocial in Nature

48. Neurotransmitters