BIOPSYCHOLOGYEverything that is psychological is

simultaneously biological.

Nervous system, endocrine system, genetics and prenatal environment

DIVISIONS OF THE NERVOUS SYSTEM

• Central nervous system • Peripheral nervous system

DIVISIONS OF THE NERVOUS SYSTEM

• Somatic nervous system • Autonomic nervous system

DIVISIONS OF THE NERVOUS SYSTEM

• Sympathetic nervous system

• Parasympathetic nervous system

• Think: “para-”

chute as it slows

you down.

Nervous System

• Steps of the neural chain

Part Definition Function

A. dendrites Bushy fibers of one end of the

neuron that receive information

Are stimulated into activity by

neurotransmitters

B. axon Pass the information through the

cell from the dendrites

The path of the electrical

impulse (action potential) thru

neuron

C. myelin

sheath

Layer of fatty tissue that insulates

the axon of some neurons

Speeds the electrical impulse

down the axon; degenerated

by multiple sclerosis

D. axon

terminal

The end of the neuron Upon stimulation it released

neurotransmitters into the

synapse or takes them back up

(reuptake)

E. synapse The tiny gap between dendrites and

axon terminals

The space btw where the

neurotransmitters move from

axon terminal to dendrites

F. vesicles Tiny, near spherical packets within

the axon terminal that contain high

concentrations of neurotransmitters

Stores the NT until the action

potential triggers its release

into the synapse

Neurons: the cells that make up the nerves

Types of Neurons

• Sensory (afferent) vs. Motor (efferent) neurons:

• Sensory/afferent neurons take messages away from sensory organs to the brain.

• Motor/efferent neurons take messages from the brain to the muscles resulting in motor tasks.

• Interneurons: central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs. We have billions and billions of these.

Neural communication in the cell

• Neurons are either excited or inhibited and it is “all or nothing”…most votes wins!

Neural communication in the cell

• When “excited” an electrical impulse called an action potentialtravels down the axon and it is propagated by the opening and closing of sodium and potassium “gates.”

Neural communication between cells

• A synapse (gap) exists between an axon and a neighboring dendrite. When stimulated the axon terminal will release neurotransmitters into the synapse wear they will travel to excite the next neuron.

NeurotransmittersNeurotransmitter Effect

Norepinephrine Helps control alertness and arousal; compliments adrenalin

Epinephrine NT that functions to speed up body processes, is highly arousing,

chemically identical to adrenalin but is released by neurons.

Endorphins “endogenous morphine” natural opiates that are released in

response to pain and vigorous exercise; an inhibitory NT resulting in

pain reduction and pleasurable feelings

Acetycholine (ach) Plays a role in learning and memory. Messenger between a motor

neuron and a skeletal muscle. Allows for the contraction of muscles.

90% depletion of ACH in ppl with Alzheimer’s disease.

Dopamine An inhibitory NT. It is strongly associated with our reward system. If

it feels good, it probably involves dopamine. Excessive activity at

dopamine receptors has been linked to schizophrenia; reduced is

associated with Parkinson’s disease.

Serotonin Affects mood, hunger, sleep, and arousal. Prozac and similar anti

depressants raise serotonin activity and reduces feelings of anxiety.

GABA NT that functions almost always as an neural inhibitor; it helps you

to relax. Alcohol and enhance GABA and bring on sleep.

Chemically Manipulating NT’s

• AGONIST: A molecule that mimics the effects of a NT or blocks the reuptake of a NT so the effects are prolonged. Agonists excited neurons.

• Ex: The venom of a black widow spider acts as an ACH agonist, leading to painful muscle contractions, convulsions, and possible death

• ANTAGONIST: A molecule that inhibits a NT release.

• EX: Botulin, a poison that can form in improperly canned foods, causes paralysis by blocking ACH release from a sending neuron. (Botox works the same way, reducing wrinkles.)

Research has shown that your mood

is influenced in part by the amount of

serotonin receptor binding. When you

are happy, it is likely that you have

more serotonin receptors activated.

Positive events in your life (like falling

in love, perhaps) cause greater

serotonin release, increasing receptor

binding.

After a little while the serotonin

molecule will detach ("unbind") from

the recepter and float back into the

synapse. When this happens, the

receptor stops sending chemical

signals to the cell body, and it waits

for another serotonin molecule to

come along.

(Those yellow things on the membrane of the axon terminal are serotonin reuptake transporters.)

About an hour or so after you take Ecstasy(the peak experience)

When you take

Ecstasy, the vesicles

release enormous

amounts of serotonin

into the synapse.

This significantly increases serotonin receptor binding (more

serotonin in the synapse means a greater chance for some of them

to bind to the receptors). This increased receptor activity leads to

significant changes in the brain's electrical firing and is primarily

responsible for the MDMA experience (i.e. empathy, happiness,

increased sociableness, enhanced sensation of touch, etc.).

Notice that there is

some dopamine in the

synapse as well (the

blue things).

MDMA also causes

dopamine release

(from dopamine

cells).

As you can see,

dopamine

receptors have also

been activated.

Long term effects• Research has shown people who have once used

MDMA regularly have measureable degrade in memory function, attention problems, and impaired executive function such as decision making and planning. They also measure within range to be diagnosed with depression.

• Data is statistically significant (likely not due to chance) BUT confounding variables such as alcohol use and use with other drugs as well as the fact that these a self-reports, not necessarily a representative sample make it difficult to draw causal conclusions.

ENDOCRINE SYSTEMGLAND/ORGAN LOCATION FUNCTION

Hypothalmus Brain Controls the master gland, pituitary

Pituitary gland Brain Secretes many different hormones which

regulate the other glands

Thyroid Neck Controls metabolism

Adrenal glands Attached to kidneys Release adrenalin which regulates heart rate,

respiration, “fight or flight”

Pancreas Near the stomach Regulates level of sugar in the blood

Ovary Lower abdomen of

women

Secretes female sex hormones

(estrogen/progesterone)

Testes Testicles Secretes the male sex hormone testosterone

ENDOCRINE SYSTEM

Hormones vs. Neurotransmitters• Some hormones, like adrenaline, are chemically

like neurotransmitters. Therefore, hormones & NTs function in very similar ways.

• They differ in processing speed: NTs communicate very rapidly and hormones move much more slowly throughout the body.

• But even though it takes longer for hormones to have their effect, the effect is often more long lasting.

• Brain > pituitary gland > other glands > hormones > brain

The BRAINThe brainstem consists of the medulla, pons, and

reticular formation. Part of the

brain

Location Purpose/function

Medulla

(aka medulla

oblongata)

Top of the spinal

cord, located in

the skull

Basic life sustaining functions: heart beat,

breathing, vomiting , salivation, coughing, &

sneezing; damage here is frequently fatal

Pons Anterior to (to

the front of) the

medulla

Latin for “bridge”, origins of cranial nerves

that cross from left to right sides of the brain.

Involved with communication between the

cerebellum and the cerebral cortex.

Reticular

formation

Within the

medulla & pons

Network of neurons that filters incoming

stimuli to other areas of the brain; controls

arousal

THE BRAINThe thalamus sits atop the brainstem and the cerebellum is

located to the rear of the brainstem.

Part of the

brain

Location Purpose/function

Cerebellum Rear of

brainstem,

base of brain

“little brain” coordinates voluntary

movement, enables one type of

nonverbal learning & memory;

Thalamus top of

brainstem

Receives information from all sense

(except smell) & routes to higher brain

regions; also receives info from brain that

goes to cerebellum & medulla

THE BRAINThe limbic system lies on the border of the brain’s older

evolutionary parts and the most advanced cerebral hemisphere.

Hypothalamus Below the

thalamus

Monitors blood chemistry, controls the

pituitary gland (master gland); key to

motivated behaviors such as hunger, thirst,

sexual drive, fight or flight…

Amygdala Top of brainstem Influences aggression and fear, activated by

emotions

Hippocampus Top of brainstem Keeps track of memories

THE BRAINThe cerebral cortex is the outer layer of the brain’s

hemispheres. It is the body’s control and information-processing center.

Lobes Purpose/function

Occipital lobe Rear areas of the cerebral cortex; vision center

Parietal lobe Top to rear area of the cerebral cortex; includes the sensory

cortex

Temporal lobe Side area of the cerebral cortex (above ears); hearing

Frontal lobe Front area of the cerebral cortex; speaking and motor

activities, higher order thinking such as planning, judging,

problem solving

OTHER CORTICAL AREAS(Other areas of the cerebral cortex)

• Association area (cortex): any of the various areas of the cerebral cortex that are not involved primarily in sensory or motor function.

• Broca’s area: area of the frontal lobe associated with the control of speech. (Think “boca”=mouth in Spanish)

• Wernicke’s area: area association with the interpretation of sound

• Aphasia: loss or impairment of the ability to understand language or express oneself through language due to injury or illness.

Illustration of brain structures involved in making conversation.

The Anatomy of the Brain

• http://www.gwc.maricopa.edu/class/bio201/brain/brshpx.htm

THE BRAINCorpus callosum Band of neural fibers that connecting the two brain

hemispheres and carrying messages between them

Left hemisphere Controls the right side of the body, primary location for

speech (Broca’s area), also specialized for math ability,

calculation, and logic

Right hemisphere Controls the left side of the body, visual & spatial

relations, perception is primarily processed here, music &

art better understood on this side of the brain, creativity

and intuition are also found here.

THE BRAIN

• ** The idea that we are “left” or “right” brained has been over simplified by “pop” psychology articles. We all use both sides of our brains and anyone who has sustained damage to one or both sides of the brain shows remarkable compensation made by the opposing side.

• “wax on, wax off”

activity

BRAIN SCANSTest What does it stand for? How does it work? When is it used?

EEG Electroencephalogram Reading of electrical

waves traveling across

the brain

Stimuli evoke electrical

impulses which will be

picked up by the EEG

Lesions Removal or damage to

selected brain matter

Animal studies, biopsies,

removal of damaged

tissue

CAT Computed tomography x-ray photographs Identify head trauma,

fractures

PET Positron emission

tomography

Shows areas of chemical

“consumption” (glucose)

w/radioactive tracers

Research which parts of

the brains are active or

inactive by following the

tracers

MRI/

fMRI

Magnetic resonance

imaging

Magnets align neural

atoms which give off

signals when returning

to normal

See the soft tissue and

fluid areas of the brain

and the blood flow

BRAIN SCANS

GENETICS & HUMAN BEHAVIOR

Behavioral geneticists study our differences and weigh the relative effects of heredity and environment.

NATURE VS. NURTURE

Genetically, all humans are 99.9% identical. It is the .1% in conjunction with varying environmental factors that makes us all unique.

Human traits are influenced by gene complexesmeaning multiple genes play a role in height, intelligence, temperament, etc.

GENETICS & HUMAN BEHAVIOR

• TWIN STUDIES

Identical >>

Fraternal

Genetics & Behavior

• Identical twins share identical genes and very similar developmental environments

• Fraternal twins share 50% of the same genes and very similar developmental environments

• Separated identical twins share identical genes but very different developmental environments.

Genetics & Behavior

• Research shows that identical twins are much more similar behaviorally than non-identical twins.

• Lykken & McGue found that you are 5.5 times more likely to divorce if your identical twin had divorced.

• Loehlin & Nichols found identical twins to be more similar in abilities, personal traits, and interests, regardless of parental treatment.

Genetics & Behavior• Genetically identical twins reared apart in different

families have consistently shown significant similarities in personality, interests, and behaviors. Those reared together are even more similar.

• Genetically identical twins reared apart have more in common than fraternal twins reared apart.

• Though some researchers feel this may be all due to “chance,” (Besides, how many sets of identical twins reared apart actually exist?) adoption studies strengthen the genetic argument in that adopted children are often NOT similar to their adoptive parents.

Nature vs. Nurture

• “Nurture works on what nature endows.”

• Example: Some people are physiologically more prone to eating disorders, but the environment/culture to which they are exposed can/will enhance their chances or developing an eating disorder.

• What implications does knowing one’s genetic make up and “risk” factors have for our future?

Behavioral geneticists vs. Evolutionary psychologists

• Behavioral geneticists are interested in what makes us unique and in how and why we differ from one another.

• Evolutionary psychologists focus on how we are alike as humans, what commonalities we share.– All people in all cultures show favor to sweet and

fatty foods because the consumption of these are beneficial to survival of famine. Unfortunately, today famine is not often a risk factor, yet we still are driven to consume fatty foods >> obesity.

Mean Genes is a book by Drs. Terry Burnham and Jay Phelan that explores the genetic explanations for our behaviors such as spending habits, eating habits, intimacy, and mating.

Environmental Factors• Prenatal environment: prenatal care, placentas, etc.

• Enriched environment: “Those with the most toys win!” Without exposure to written or signed language prior to adolescence one will never master it.

• Parenting: Has its greatest influence when extreme (abusive, neglectful, etc.)

• Peer Influence: The selection of peers makes it powerful. A child is more likely to become a smoker if peers smoke but not if parents smoke.

• Parent decisions (like where to live) will influence peer selection.