Brain and Behavior and Drugs: 2nd 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
  cortexits association areasare 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
Aphasia is an impairment of language, usually
caused by left hemisphere damage either to
Brocas area (impaired speaking) or to Wernickes
area (impaired understanding).
6
Specialization Integration

• Brain activity when hearing, seeing, and speaking
  words

7
The Brains Plasticity

• The brain is sculpted by our genes but also by
  our experiences.
• Plasticity refers to the brains 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 Brains 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
  drugs effect lessens. Thus it takes greater
  quantities to get the desired effect.

17
Withdrawal Dependence

1. Withdrawal Upon stopping use of a drug (after
   addiction), users may experience the undesirable
   effects of withdrawal.
2. 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.

1. Depressants
2. Stimulants
3. Hallucinogens

19
Depressants

• Depressants are drugs that reduce neural activity
  and slow body functions. They include

1. Alcohol
2. Barbiturates
3. Opiates

20
Depressants

1. Alcohol affects motor skills, judgment, and
   memoryand increases aggressiveness while
   reducing self awareness.

Daniel Hommer, NIAAA, NIH, HHS
Moderate Alzheimers
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

1. Caffeine
2. Nicotine
3. Cocaine
4. Ecstasy
5. Amphetamines
6. 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

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

29
Hallucinogens

1. LSD Powerful hallucinogenic drug Serotonin
   agonist.
2. 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.

1. Drug Therapies
2. Brain Stimulation
3. 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 Parkinsons 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