Download Forebrain cont`d

Vocabulary (Ch 3 & 4)
Central nervous system
peripheral nervous system
Sensory nerves
biological rhythm
Split-brain surgery
hemispheric dominance
Reticular activating system
cortisol
Limbic system
adrenal glands
epinephrine
Temporal lobes
frontal lobes
corpus callosum
REM sleep
cell body
hypothalamus
Prefrontal cortex
plasticity
synapse
medulla
Content
 Development and cultural context
* Historical and cultural conditions that gave birth to perspective.
* Contributions and current standing.
Framework* Key concepts
* Assumptions
* Theoretical explanation of behavior change
Methodologies
* Methods
* Strengths and limitations
* Ethics
Application
* Effectiveness in explaining psychological questions
* Recommendations for change in lifestyle
Biological Perspective:
Extra Credit
• Genetic influences on behavior
• Look for magazine and newspaper articles that deal with
BIOLOGY & PSYCHOLOGY (MUST be both – not one or
the other). For example: you might find an article describing
research that indicates schizophrenia is caused by a chemical
imbalance in a person’s body.
•
You must give a short summary of the article to the class.
• The FIRST person to turn in the article will receive extra
credit points. (5 points for each article)
Where do human commonalities
come from?
• Name characteristics of behavior shared by
all human cultures:
1. Language
2..
3..
4..
5..
Where do human differences
come from?
• Name characteristics of behavior that are
different based on individuality:
1. .
2. .
3. .
4. .
5. .
BIOLOGICAL
Development and cultural
context
• Focus:
–interaction between the physiological and
psychological factors that contribute to
behavior.
•Behavioral change can be regarded as arising from an
interaction between innate disposition and environmental
factors.
•There is an acceptance that not only environmental factors
shape and alter the brain (plasticity) but culture has an
influence as well.
BIOLOGICAL
• IN THE PAST
• Oversimplified and reductionistic
• Assumed that inherited factors directly determined
behavior
• Assumed that the brain was fairly intact at birth
• Early Greek times: Galen and Hippocrates believed
personality and temperament were linked to levels of body
fluids (bile, blood)
• Now viewed as much more complex
BIOLOGICAL
Framework
Basic Assumptions
• Nativists:
– Emphasized genes and inborn characteristics (nature)
• Edward L. Thorndike (1903) claimed that “in the actual race of
life…the chief determining factor is heredity”
• Empiricists:
– Focused on learning or experience (nurture)
• John B. Watson (1925) insisted that experience could write
virtually any message on the blank slate of human nature” (using
John Locke’s theory that when humans are born their minds are a
blank slate - tabla rosa)
•
Cognition, behavior and feelings are strongly affected by the ways in
which the human brain works. Biological psychologists reject the idea
that the mind exists independently of the physical brain. Biological and
cognitive sciences are closely tied, called psychoneurology.
• Remember: A bi-directional approach viewing biology as inherited
AND acquired, better explains human behavior.
BIOLOGICAL
Development and cultural
context
Evolutionary Biology
•Darwin
– natural selection: the fate of genetic
variations depends on the environment.
– Over the past century and a half, these
evolutionary principles have been resoundingly
supported by findings in anthropology, botany
and molecular genetics and now guide all of
the biological sciences.
BIOLOGICAL
Development and cultural context
•How can we explain our human differences and similarities?
- Evolutionary psychologists
•Believe the answer lies in genetic dispositions that developed
during the evolutionary history of our species.
•Believe the human mind evolved as a collection of specialized and
independent “modules” to handle specific survival problems.
* Dislike for bitter tastes
- Evolutionary biological psychologists
•Start with an observation about some
characteristic and try to account for it in
evolutionary terms.
* Male peacocks
- Critics
•The idea of mental modules is no improvement over the instinct
theory. (all human activity is innate)
Nature vs. Nurture
Obesity
Nature
Nurture
Confounding
Hate mother
Genetic Set point
Low cost /high fat foods
Sexually repressed
Chemical regulations
Over processed foods
Emotionally disturbed
Metabolism
Couch potato lifestyle
Basic Biology 101
• Genes: basic units of heredity located on chromosomes
that contain DNA.
• Each gene contains 23 matched pairs of chromosomes
(except sex cells).
• Chromosomes: rod shaped structures found in every cell
of the body.
Human genes: 30,000-150,000
• Some genes are unique to each
human
• Some genes are shared by all
humans and other animals
• DNA is broken into 4 basic elements
(ATCG). The combination of each letter
defines that gene.
• Example: (ACGTCTCTATA) = one gene
• Linkage studies:
• There are over 3 Billion combinations
possible.
Genetics
• Not all traits are equally heritable or unaffected by
shared environment
• Some studies may underestimate the impact of the
environment
• Even traits that are highly heritable are not rigidly
fixed and can be modified by experience
• Twin Studies:
•Heston et all (1966)- Schizophrenia
•Tienari importance of environment
• The Human Genome is the full set of genes
in each cell of an organism.
• Most traits depend on more than one gene
pair.
• Linkage studies look for genetic markers
that are linked to specific genetic traits.
• Studies also look for inherited genes close
together to identify genetic markers.
Genetics
• Heritability
• Estimate of heritability applies only to a particular group
living in a particular environment.
• Intellectual ability
• Heritability estimates do not apply to individuals, only to
variations within a group
• Genetic mosaic
• Even highly heritable traits can be modified by the
environment
• Height
• Computing Heritability
• Adopted children studies
• Identical and fraternal twin studies
Genetics cont’d
• Heritability and Intelligence
• Genes and individual differences
• Identical Twins
• Fraternal Twins
• Adopted children
• Group differences
• Racism effects
• Same conditions, different results?
• Heredity & Temperament
• Reactive/nonreactive
• Heredity & Traits
• Trait = way of behaving, thinking, feeling
• Extrovert/introvert • Agreeableness
• Conscientiousness
• Negativity
• Openness to experience
THE ROLE OF GENES
• Genetic influences on behavior
•Virtually all behavior is influenced by genes.
•Virtually no behavior is determined by genes.
• Twin studies
• IQ tests
• Identical( raised together) – highly correlated
• Identical (raised apart) – correlated to non-identical
• Adoption studies
• Correlated to their birth parents’ scores more than adoptive
parents’ scores
THE ROLE OF GENES cont’d
• Birth order
– Does birth order determine IQ?
Problem: IQ heritability estimates are based mainly on white samples
• Genetically determined temperaments
• Differences in activity level, mood, responsiveness,
soothability, attention span
• May later form basis of personality traits
• Heredity & traits
• Habitual way of behaving, thinking and feeling
• Behavioral geneticists are finding that many traits are highly
heritable
BIOLOGICAL
Development
• Scientific discoveries about biological processes
–Mind and body effect each other
* Placebo effect
“If you treat just the disease without treating the emotional
devastation caused by the disease you’re only treating half a
patient.” Norman Cousins, journalist
–Physiological psychology
* Brain:
– 3 ½ pounds
– neurons (individual nerve cells), 10 billion approx.
– both electrical and chemical
– Only olfactory neurons in the nose are capable of regenerating
themselves
– 1990 scientists at John Hopkins kept a lab culture of
cerebral cortex neurons alive and multiplying
Brain labeled
• Hindbrain
* regulates body’s basic activities
* Connects directly to the spinal cord
* Three parts
-Medulla
-Connection between brain and
spinal cord
-Regulates breathing, heartbeat
and blood pressure
-Cerebellum
-maintains body’s balance
-coordinates fine-muscle
activity
• Hindbrain cont’d
-Reticular Activating System (RAS)
*attention center of the brain*
center of balance for the other
systems involved in learning, selfcontrol or inhibition, and
motivation
region of brainstem
-signals that control wakefulness and sleep
-signals that control arousal and alertness
-sorts out messages from constant flow of
trivia by sensory receptors
* When RAS does NOT excite neurons as it ought to
Poor memory
Difficulty learning
Lack of self-control
* When RAS excites neurons TOO MUCH
Excessive startle response
Restless
Talking too much
Hyperactivity
Touching everything
* Disorders that effect the hindbrain
Sleep disorders
ADHD, ADD
Stroke
• Forebrain
* Conscious thought
* Pleasure and pain
* Three parts
* Thalamus
»connects the forebrain with the rest of the body
»all incoming messages from sense organs
(except for smell) come through
»sorts messages and passes them on to the proper
groups of neurons
»Acquisition of knowledge(cognition)
* Hypothalamus
»Controls instinctive behavior
»Directs body responses to hunger,
thirst, stress (deep breathing)
»Pleasure center
• Forebrain cont’d
Cerebrum
»Allows you to experience consciousness (thought)
»Forms 60% of your brain
* divided into two cerebral hemispheres connected by a
mass of white matter known as the corpus callosum
»Cerebral Cortex divided into
four lobes (+ 1 part) and
contains most of the specific
areas that affect
* muscle coordination
* memory
* concentration
* problem solving
* decision making
• Forebrain cont’d
Cerebral cortex lobes
Occipital lobe
»Located in the back of the head
» Interprets the signals transmitted by
the eyes an allows you to “see”
Temporal lobe
»Located at the side of the head
»Handle both auditory and olfactory senses
Parietal lobe
»Located at the top of the head
»Governs sense of touch
»Keeps track of different parts of the body
(If sensory motor cortex were to be
damaged…)
• Forebrain cont’d
Frontal lobe
»Plays a key role in creativity,
emotional control and attention span
»Provides coordination that keeps feet,
legs, arms, etc. working together
»Large portion devoted to hands and
mouth
»Because tool use and spoken
language are the major
developments separating humans
from lower animals, this unequal
development makes biological
sense
* Insula - located deep within - association center
Left brain vs. Right brain
• Connected by corpus callosum
Which allows the two hemispheres to
function in a coordinated fashion
• If one side is damaged the other side is
able to take over some functions it does
not normally perform
Ex. Language & stroke victims
Left brain vs. Right brain cont’d
• Left hemisphere
Controls right side of body
Right-hand dominance
uses logic
detail oriented
facts rule
words and language
present and past
math and science
can comprehend
knowing
acknowledges
order/pattern perception
knows object name
reality based
forms strategies
practical
safe
90% of the world
• Right hemisphere
Controls left side of body
Left-hand dominance
uses feeling
"big picture" oriented
imagination rules
symbols and images
present and future
philosophy & religion
can "get it" (i.e. meaning)
believing
appreciates
spatial perception
knows object function
fantasy based
presents possibilities
impetuous
risk taking
Split Brain surgery
• Roger Sperry
• Michael Gazzaniga
* Corpus callosum is severed
* Performed in patients
suffering from epilepsy
Disorders that affect the brain
Region
Cerebral cortex
Disorder
depression, Huntington's disease,
mania
Cerebrum
epilepsy, stroke
•frontal lobe
Alzheimer's disease, depression,
mania
•parietal lobe
Alzheimer's disease
•temporal lobe
Alzheimer's disease, depression,
mania
Limbic system
mania
•amygdala
depression
•hippocampus
Alzheimer's disease, mania
• Neuron
• Neural pathway (biological “wiring” of the brain)
• Cell body
• Nucleus – where equipment is located
• Dendrites
• Carry the signals
• Axon
• Carries the impulses from cell body to the
dendrites of nearby neurons
Nerve impulse
Axon
Neurotransmitters
Receptor molecules
Dendrite of receiving
neuron
• Problems
* Neurons cannot “regrow” (except for
hippocampus)
• Multiple Sclerosis
• Damage to myelin which does not allow
messages to pass where they need to go
• Epilepsy
• In epilepsy this order is disrupted by some
neuron discharging signals inappropriately. There
may be a kind of brief electrical "storm" arising
from neurons that are inherently unstable because
of a genetic defect (as in the various types of
inherited epilepsy), or from neurons made
unstable by metabolic abnormalities such as low
blood glucose, or alcohol.
• Endocrine glands
• hormones
• Regulate everything from
physical growth to sexual
functioning
• Most important: pituitary,
adrenal, thyroid, sex glands
• Pituitary
• Regulate growth
hormones
• Adrenal
• Prepares the body to
cope with emergencies
• Regulates chemical
balance of the body
• Endocrine glands cont’d
• Neurotransmitters
• Thyroid
• Determines the body’s energy
level
• Severe thyroid deficiency can
affect intellectual development
• Sex glands (gonads)
• Ovaries/testes
• Regulate the development of sex
organs and prepares the body for
reproduction
CHEMICAL MESSENGERS
• Neurotransmitters
•Serotonin
•Sleep, sensory perception, pain suppression, mood
•Dopamine
•Voluntary movement, learning, memory, emotion
•Acetylcholine
•Muscle action, cognitive functioning, memory, emotion
•Norepinephrine
•Learning, memory, dreaming, emotion, increased
heart rate and slowing of intestinal activity during
stress
•Glutamate
•Plays critical role in long-term memory
•GABA (gamma-aminobutyric acid)
•Inhibitory neurotransmitter
CHEMICAL MESSENGERS
• Neurotransmitters, cont’d
•Problems when too high or too low
•Low serotonin and norepinephrine
•Severe depression
•Abnormal GABA levels
•Sleep & eating disorders
•Loss of acetylcholine
•Memory loss
•Related diseases
•Alzheimer’s Disease
•Lose brain cells responsible for producing
acetylcholine
•Leads to memory loss, personality changes and
eventual disintegration of all physical and mental
abilities
CHEMICAL MESSENGERS
• Endorphins – the brain’s natural opiates
•Play a role in:
•Reducing pain
•Promoting pleasure
•Appetite
•Learning
•Sexual activity
•Blood pressure
•Mood
•Memory
CHEMICAL MESSENGERS
• Hormones
•Adrenal hormones
•Produced by adrenal glands
•Involved in emotion and stress
•Also respond to heat, cold, pain, injury and physical
exercise
•Melatonin
•Secreted by the pineal gland
•Promotes sleep
•Regulate daily biological rhythms
•Biological rhythms – hormone levels, daylight, menstrual
•Circadian rhythms – occur approx every 24 hrs, sleep/wake cycle
•Controlled by a biological clock – melatonin keeps in
phase with light/dark cycle
CHEMICAL MESSENGERS
• Hormones cont’d
•Sex hormones
•Secreted by tissue in the gonads & adrenal glands
•Occurs in both sexes but in different
amounts after puberty
•Androgens – masculinizing hormones(most imp.
Testosterone)
•Mainly in testes but also in ovaries and adrenal glands
•Estrogens & Progesterone – feminizing hormones
•Mainly in ovaries but also in testes and adrenal
glands
•Research continues on contributions of hormones in
behavior not directly related to sex and reproduction
APPLICATIONS
• Neuropsychology – Uses techniques to study the brain
• EEG (electroencephalograph)
a recording of electrical signals(neural signals) from
the brain made by hooking up electrodes to the
subject's scalp.
• MRI (magnetic resonance imaging)
This complicated technique uses magnetic fields and
radio waves to produce an image of brain structure on
a computer.
APPLICATIONS – Cont’d
• PET (Positron Emission Tomography)
A method for analyzing biochemical
activity in the brain, using injections of a
glucose-like substance containing a
radioactive element.
• CAT (Computed Axial Tomography)
Uses special x-ray equipment to obtain image data from
different angles around the body and then uses computer
processing of the information to show a cross-section of
body tissues and organs.
Mental Disorders
• Mental disorders can have a
physiological basis and may arise from
changes in brain chemistry.
•Mental disorders can be divided into various
classes.
•Among them are:
•Delirium, dementia, and amnestic and other cognitive disorders
•Anxiety disorders
•Schizophrenia and other psychotic disorders
•Mood disorders
•Impulse-control disorders
•Personality disorders
•Eating disorders
• Depression
Applications
Mood disorder most closely associated with
persistent sadness
• Memory
The capacity to retain and retrieve information,
and also to the mental structures that account for
this capacity.
• Aggression
A forceful action or procedure; hostile, injurious
or destructive behavior
• Language
Set of rules for combining elements that are in
themselves meaningless into utterances that convey
meaning
APPLICATIONS
Cont’d
• Psychosurgery
*Lobotomy
•?Surgeons separate some of the cables connecting
the frontal lobes to the thalamus
*Cingulotomy
•?Surgeons separate some of the nerve tracts from the
frontal lobes to the cingulate gyrus which is the place in
our brain supposedly responsible for mediating anxiety.
With neural cords cut, anxious, obsessive messages
can’t get through.
*Electroconvulsive Therapy
•Sterile seizures are introduced …
APPLICATIONS Cont’d
• Medications
*Anti-depressants
•Act by… (Drugs and Behavior)
• Gender Differences
•
Men and women display patterns of behavioral
and cognitive differences that reflect varying
hormonal influences on brain development
BIOLOGICAL
Methodologies
• Biology is a science, psychology is a science.
Thus, experimental method is frequently used.
• Correlates of biological processes to human
behavior can be established and triangulated.
• Analogue research with animals establishes a
base from which to consider human behavior.
• Neuropsychology uses techniques to study the
brain such as EEG and scanning techniques
(structural imaging-CAT and MRI and
*functional imaging PET scans) to give info on
aggression, stress and learning. (see handout brain and
behavior 83)
BIOLOGICAL
Treatment Approaches
1. What treatment provides the best outcome for depressed
patients?
2. What is one advantage of biological treatment?
3. Explain the medical model of mental illness.
4. Explain the problems associated with anti-anxiety drugs.
5. What is the treatment psychosurgery & who developed it?
6. What is the difference between organic disorders &
functional mental disorders?
7. What are the drawbacks of anti-psychotic medications?
8. What are the three major kinds of biological treatments?
9. What questions must a researcher ask when determining if
a disorder has a biological cause.
10. Explain the use of electroconvulsive therapy
11. In what percentage of bipolar patents are anti-bipolar
drugs effective?
12. What are three problems with biological treatments?
13. What are the benefits of anti-psychotic medications?
BIOLOGICAL
Strengths and limitations
• Strong methodology
• Objective
• Applications in
mental disorders very
effective
•
•
•
•
Reductionist
Can be over simplistic
Ethical considerations
Animal research may not serve
always as correlational
evidence to understanding
human behavior
• Pinning down a relationship between neurotransmitter abnormalities
and behavioral abnormalities is extremely difficult. Drugs that boost
or decrease neurotransmitter levels, are sometimes effective in
treating disorders but does mean that this causes disorders. After all,
aspirin can relieve a headache, but headaches are not caused by a lack
of aspirin.
CAN YOU??
* List at least five researchers who are KEY to the school?
* Explain the key ideas that dominate the perspective?
* Explain the attitude toward determinism?
* Explain the application of the perspective to certain issues,
including: Dysfunctional psychology and therapy,
Development, Education, or Personality development?
* Ethical issues and other criticism of the research?
* The methods employed by the perspective for research?
* Issues of Cross-culturalism