Title: Brain and Behavior and Drugs: 2nd pt Chapter 3
1Brain and Behavior and Drugs 2nd ptChapter 3
2Association 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.
3Association 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.
4Association Areas
- More intelligent animals have increased
uncommitted or association areas of the cortex.
5Language
Aphasia is an impairment of language, usually
caused by left hemisphere damage either to
Brocas area (impaired speaking) or to Wernickes
area (impaired understanding).
6Specialization Integration
- Brain activity when hearing, seeing, and speaking
words
7The 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.
8The 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.
9Our 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.
10Splitting 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
11Split 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.
12Divided Consciousness
13Try This!
Try drawing one shape with your left hand and one
with your right hand, simultaneously.
BBC
14Drugs Affecting our own Consciousness
- Dependence and Addiction
- Psychoactive Drugs
- Influences on Drug Use
15Drugs and Consciousness
- Psychoactive Drug A chemical substance that
alters perceptions and mood (affects
consciousness).
16Dependence 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.
17Withdrawal 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).
18Psychoactive Drugs
- Psychoactive drugs are divided into three groups.
- Depressants
- Stimulants
- Hallucinogens
19Depressants
- Depressants are drugs that reduce neural activity
and slow body functions. They include
- Alcohol
- Barbiturates
- Opiates
20Depressants
- Alcohol affects motor skills, judgment, and
memoryand increases aggressiveness while
reducing self awareness.
Daniel Hommer, NIAAA, NIH, HHS
Moderate Alzheimers
21Depressants
- 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.
22Depressants
- 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
23Stimulants
- Stimulants are drugs that excite neural activity
and speed up body functions. Examples of
stimulants are
- Caffeine
- Nicotine
- Cocaine
- Ecstasy
- Amphetamines
- Methamphetamines
24Caffeine Nicotine
- Caffeine and nicotine increase heart and
breathing rates and other autonomic functions to
provide energy.
25Cocaine
- 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
26Ecstasy
- 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.
27Methamphetamines
- Highly Addictive
- Triggers strong release of dopamine,
norepinephrine, and serotonin
28Hallucinogens
- Hallucinogens are psychedelic (mind-manifesting)
drugs that distort perceptions and evoke sensory
images in the absence of sensory input.
29Hallucinogens
- LSD Powerful hallucinogenic drug Serotonin
agonist. - THC Cannabinoid receptors are found in parts of
the brain that influence pleasure, memory,
concentrating, time perception and coordinated
movement.
30Marijuana Use
The use of marijuana in teenagers is directly
related to the perceived risk involved with the
drug.
31Influences on Drug Use
The use of drugs is based on biological,
psychological, and social-cultural influences.
32Drugs Other Therapies
- Drug Therapies
- Brain Stimulation
- Psychosurgery
- Therapeutic Life-Style Changes
33The Biomedical Therapies
- These include physical, medicinal, and other
forms of biological therapies.
- Drug Therapies
- Brain Stimulation
- Psychosurgery
34Drug Therapies
- Psychopharmacology is the study of drug effects
on mind and behavior.
With the advent of drugs, hospitalization in
mental institutions has rapidly declined.
35Drug Therapies
- Many patients are left homeless on the streets
due to their inability to cope independently in
society.
Margaret Holloway aka The Shakespeare Lady
36How Neurotransmitters Influence Us
Serotonin pathways are involved with mood
regulation.
37Dopamine Pathways
Dopamine pathways are involved with diseases such
as schizophrenia and Parkinsons disease.
38Antipsychotic 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.
40Antianxiety 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.
41Antidepressant 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.
42Mood-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.
43Brain 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.
44Alternatives 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.
45Psychosurgery
Psychosurgery was very popular even in Neolithic
times. Although used sparingly today, about 200
such operations do take place in the US alone.
Lobotomy
46Psychosurgery
- 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.
47Psychological Disorders are Biopsychosocial in
Nature
48Neurotransmitters