Transcript Unit III: Biological Bases for Behavior

Unit III
Biological Bases for Behavior
Essential Question:
How might bodily functions influence behavior?
Biology, Behavior, and Mind
Biological psychologists: deal with the scientific
study of the links between biological and
psychological process.
A.K.A.: behavior neuroscientists,
neuropsychologists, behavior geneticists, etc.
Pair Partner Mini-Discussion:
What courses might a person who is
seeking a degree in biological
psychology be required to take to
complete their degree?
Neural Communication
https://www.youtube.com/watch?v=6qS83wD29PY
Neurons – aka “nerve”
1. Dendrites: the fiber-like extensions from the cell body that receives information and moves
that information towards the cell body
2. Cell body: the control/support center of the neuron
3. Axon: the long arm/extension of the neuron which the information passes through
Action potential: the electrical impulse that travels through the axon
4. Myelin sheath: the fatty layer or “sleeve” of the axon that serves to speed up the process
of the electrical impulses
5. Axon Endings/Terminal branches of axon: releases the information to the next cell in the
form of chemicals
Refractory period: nanosecond period of time AFTER the information has been released
from the neuron
So, how do neurons communicate?
DENDRITES  passes through CELL BODY through the AXON
 where it turns into an electrical impulse and is sped up by
the MYELIN SHEATH  turns back into a chemical form within
the AXON ENDINGS/TERMINALS  released across the SYNAPSE
(in the form of NEUROTRANSMITTERS)
Whole Class Activity
Neural Information Highway:
1. Everyone must stand up and form a large circle around the room, with a
line of 3 students and cluster of 4 students in the center (serving as the
spinal cord and brain)
2. Persons around the room  Your arm and stretched-out hand will serve as
an individual “neuron.”
3. A note will be passed through each “neuron,” then through the “spinal
cord,” and to the “brain”.
4. The “brain” will then send a message back to the last “neuron” to perform
an “action”.
Neurotransmitters and their Functions
Neurotransmitter
Function
Examples of Malfunctions
Acetylcholine (ACh)
Enables muscles to contract,
learning, and memory
Alzheimers – ACh neurons
deteriorate/decrease
Dopamine
Oversupply  Schizophrenia
Enables bodily movement,
learning, attention, and emotion Undersupply  Parkinson’s
disease
Serotonin
Affects mood, hunger, sleep,
and arousal
Undersupply  Depression
Norephinephrine
Controls alertness and arousal
Undersupply  Depression
GABA
Inhibitory neurotransmitter
Undersupply  seizures, tremors,
insomnia
Glutamate
Excitatory neurotransmitter;
enables memory
Oversupply  produces
migraines/seizures
Effects of DRUGS on the Brain
Agonists
 Similar to neurotransmitters to
bind its receptor and mimic its
effects
 Agonistic drugs tend to give a
temporary “high” by
exaggerating normal
sensations of arousal or
pleasure
 Examples: Heroin, morphine
Antagonists
 Tend to block a
neurotransmitter’s functions
 Examples: Botox, aspirin,
ibuprofen, tranquilizers
Nervous System
Central Nervous System
(CNS)
 The Control Center
 Made up of 2 parts:
BRAIN
SPINAL CORD
Peripheral Nervous System
(PNS)
 Gathers and transmits information
from the body and sends to the
Central Nervous System
 Made up a WEB of neurons that
are located under the skin and
wrapped around all of the body’s
inner organs
Peripheral Nervous System
Somatic Nervous System
Autonomic Nervous System
 Allows the body to make
voluntary motion; controls
skeletal muscles
 Allows the body to function internally…and
automatically; controls glands, and organ
muscles
Examples: pick up a
pencil, hit the ball with
the baseball bat
 Examples: heart, bladder
 Divided into 2 subdivisions:
 Sympathetic Nervous System: reacts to stimuli
that arouses and requires increased energy
 Parasympathetic Nervous System: calms the
body and returns it to normal functions
Endocrine System
Sends electrochemical messages from the body’s glands
to the brain
Mode of information transportation  HORMONES
(Chemical messengers) via the BLOODSTREAM
Parts of the Endocrine System
1. Adrenal glands – located on the top of the kidneys (function
: to release adrenaline or epinephrine); enables fight or flight
response
2. Pituitary gland – size of a pea located in the core of the
brain; BEST KNOWN FOR CONTROLLING GROWTH, but also
controls birthing, orgasms, attachment/bonding, social trust
3. Thyroid gland – controls metabolism
4. Pancreas – controls level of blood sugar
5. Reproductive Organs - Testis (male); Ovary (female)
CRASH COURSE on the BRAIN
https://www.youtube.com/watch?v=vHrmiy4W9C0
Methods to Study the Brain
1. Lesions: to destroy brain tissue (naturally or through intentional harm or
removal)
2. Electrocephalogram (EEG): amplified wave reading; records brain waves
3. Computed Tomography) (CT): X-ray pictures from different angles of the
brain that is combine to show “slices” of the brain
4. Positron Emission Tomography (PET) scan: a display of brain activity using a
radioactive form of glucose that the patient must ingest
5. Magnetic Resonance Imaging (MRI): uses magnetic fields and radio waves
to show images of the body’s soft tissues
6. fMRI: specialized machine; shows the brain’s function AND its structure
The Brainstem
Oldest, centrally located part of the brain
Medulla: controls HEARTBEAT and BREATHING
Pons: coordinates movement
Reticular Formation: enables arousal
Thalamus: brain’s sensory control center
The Cerebellum
 Size of a baseball in an adult –sized brain
 Located behind the brainstem
 Purpose: enables nonverbal learning and memory; judges
time; regulate emotions; differentiate between different
sounds and textures
Limbic System
Amygdala: controls aggression and fear
Hypothalamus: influences hunger, thirst, body
temperature, and sexual arousal
Hippocampus: processes conscious memories
The Cerebral Cortex
 A thin, surface web of neural cells that covers the brain hemispheres
 Contains 20-23 BILLION nerve cells and 300 TRILLION synaptic connections
 Glial cells  “glue cells” that cannot operate independently, but serve as
a “help” to neuron cells
Four (4) lobes:
1. Frontal lobe: directly behind the forehead
2. Parietal lobe: top rear section
3. Occipital lobe: at the back of the head
4. Temporal lobe: on the side, just above the ears
Functions of the Cortex
 Motor Cortex: allows the body parts to move
Areas of the body that require precise control (i.e. fingers, mouth)
had the greatest amount of designated space on the cortex
 Sensory Cortex: allows the body to sense touch, temperature, texture,
sound, taste, smell
 Association Areas: link sensory information with stored memories
Example: You see an orange at a distance. You are able to
remember how an orange smells, taste, or feels from memory
Language Association Areas in the Brain
(Aphasia: impaired language abilities due to damage to the cortex)
1. Visual cortex – allows you to recognize written words (visual
stimulation)
2. Angular gyrus – allows you to “hear” the words in your head
(auditory code) as you read
3. Wernicke’s area – interprets sounds/auditory codes into
meaningful information
4. Broca’s area – controls speech muscles (larynx, tongue, lips)
5. Motor cortex – word is pronounced
Plasticity
The brain’s ability to RE-WIRE itself to continue functioning
after a brain injury/stroke
Does not always occur; nature takes its course; nothing can
manipulate this process to begin earlier or happen at all
Brain has a unique way of compensating for lost abilities
by enabling other parts to take on additional
responsibilities
Example: Lost of sight  sense of touch, smell gets keener
Our Divided Brain
2 hemispheres are connected by the CORPUS
CALLOSUM (band of fibers)
In EXTREME cases, surgeons of epileptic patients may
opt to sever (cut) the corpus callosum to slow down or
eliminate the “static communication” between the
hemispheres which cause severe or frequent seizures
There is no known loss of ability due to split brain (the
severing of the corpus callosum)
Right-Left Brained …What does that
mean?
Right hemisphere  controls the left side of the body
Left hemisphere  controls the right side of the body
Individuals develop a preference to the use of their
left, right, or both hands before birth (genetic
predisposition)
Genetics, Evolutionary Psychology,
& Behavior
Behavior geneticists
Studies our differences and weigh the effects of heredity
and environment on individuals
NATURE vs. NURTURE!!!!
Gene: the
basic unit of
human traits
Chromosome:
strand of
information for
genetic
make-up
DNA: the total
unit of
information
for any one
part of the
body.
GENOME:
the
complete set
of
instructions
for making
an organism
Twin and Adoption Studies
http://www.youtube.com/watch?v=0yTCShemS_0
 Identical vs Fraternal
Identical – twins developed from the SAME fertilized egg that completely
separated during the first few weeks after conception
Fraternal – developed from TWO or MORE fertilized eggs within a narrow
timeframe
 Separated Twins
Studies were conducted on twins (identical and fraternal) that were
separated at birth (either intentionally for the benefit of the study OR due
to extenuating circumstances)
Results: Genetics undeniably played a major role! However, in some
cases, the environment was a major factor as well!
Evolutionary Tendencies
Natural Selection: individuals are likely the mate with another
individual that have strengths that they do not possess to be more
advantageous in life
Gender Differences in Sexuality
Males: more adventuresome; open to multiple
relationships/attraction
Females: less adventuresome; naturally suited for monogamous,
stable relationships