AP Psychology Unit III
[ module 9 : Biological Psychology and Neurotransmission ]
• Neurons: nerve cell
mu
b
Cell body: cell's life support center
Dendrite: fibers that receive + integrate info, conducting it
towards cell body
Axon: fibers that passes the message through its terminal
branches to other neurons or to muscles or glands
Myelin Sheath: layer of fatty tissue that insulates them and
speeds their impulses
Glial Cell: "worker bees" that participate in information
transmission and memory.
• The Neural Impulse
Neuron sends message through action potential
= 2 to 200 miles per hour
= instantaneous
*the domino effect of re (-) /de (+) polarization
(electrical charge that travels through axon)
mum
tr
generated through chemical events; ion exchange
I. Resting Potential
_ + out / - in
II. Firing of Neuron
_ gates open= Na+ floods in= depolarization (a decrease in the difference in voltage between the inside and outside
of the neuron)= next section opens, the previous section closes= etc etc
= "neural impulse" "action potential"
Excitatory: gas
Inhibitory: breaks
If excitatory exceeds inhibitory by a minimum intensity (threshold) =
combined signals trigger action potential
= travels down axon
= branches into muscles or glands
Neurons need breaks= resting pause= refractory period= action
potentials cannot occur until axon returns to resting
Neuron= all or none response: ↑stimulation ≠ ↑ impulse's intensity:
either fire or they don't
↑ stimulation = ↑ neurons to fire:
squeezing trigger harder won't make bullet faster
• How Neurons Communicate
Synapse: meeting point between the nerves -> synaptic cleft: gap not touching neurons
When action potential reaches terminals, it triggers the release of chemical messengers (neurotransmitters)
= at the end, excess drift away, are broken down by enzymes, or are reabsorbed by sending neuron (reuptake)
• How Neurotransmitters Influence Us
Neurotransmitter systems don't operate in isolation; they interact + their effects vary with the receptors they
stimulate
Neurotransmitters
Acetylcholine: Enables muscle action, learning, and memory
= Alzheimer's: ACh- producing neurons deteriorate
Dopamine: Influences movement, learning, attention, and emotions
= ↑ : schizophrenia
= ↓ : tremors and decreased mobility in Parkinson's disease
Serotonin: Affects mood, hunger, sleep, and arousal
= ↓ : depression (some drugs raise serotonin levels to treat depression)
Norepinephrine: Helps control alertness and arousal
= ↓ : depressive mood
GABA (gamma-aminobutyric acid): Major inhibitory neurotransmitter
= ↓ : seizures, tremors, and insomnia
Glutamate: Major excitatory neurotransmitter, involved in memory
= ↑ : overstimulate brain = migrants or seizures
Endorphins: Influences the perception of pain or pleasure
= ↑ with opiate drugs can suppress the body's natural endorphin supply
• How Drugs and Other Chemicals Alter Neurotransmission
Balance: if artificial drug ↑, body ↓ and suppresses natural neurotransmitter production, so when drug is
withdrawn, brain may be deprived of any form of it.
Agonist: increases neurotransmitter's actions: may ↑ production/release or ↓ reuptake in synapse
Antagonist: decreases a neurotransmitter's actions: block production or release
[ module 10 : The Nervous and Endocrine Systems ]
• The Nervous System
my
Made up of Neurons communicating with near transmitters
Central Nervous System: brain and spinal cord + the body's decision maker
Peripheral Nervous System: responsible for gathering information and for transmitting CNS decisions to other
body parts
Nerves: electrical cables formed from bundles of axons + links the CNS with the body's sensory. Receptors,
muscles, and glands
Sensory neurons: carry messages from body's tissue and sensory receptors inward (afferent)
Motor Neurons: carry instructions from CNS outward to the body's muscles and glands (efferent)
Interneurons: of spinal cord and brain + processes information btw sensory input and motor output
• The Peripheral Nervous System
1) Somatic Nervous System
= enables voluntary control of skeletal muscles
2) Autonomic Nervous System
= controls glands and internal organ muscles
= influences functions such as heartbeat and digestion
1. Sympathetic Nervous System: arouses and expends energy (fight or flight)
= accelerate heartbeat, raise blood pressure, slow digestion, raise blood sugar, sweat
2. Parasympathetic Nervous System: opposite effects (rest and digest)
*Together maintains homeostasis
• The Central Nervous System
Brain: enables humanity (thinking, feeling, acting)
86 billion neurons
- cluster into work groups (neural networks)
- works with nearby neurons to have short fast connections
- each layer's cells connect with various cells in the next layer
- experience strengthens connection: nerves are literally making stronger paths that fire and wire
together
Spinal Cord: is a two way information highway connecting PNS and brain
= ↑ : send up sensory info
= ↓ : send back motor control information
Neural Circuits
Reflexes: our automatic responses to stimuli
← Pain Reflex
Paralysis: when spinal cord "pathway" is severed
• to feel pain or pleasure, sensory information must
reach the brain via spinal cord
• Endocrine System
= another communication system
Nervous System: Neurotransmitters - fast
Endocrine System: Hormones - slower (travels through bloodstream) - tend to outlast effects
*some hormones are chemically identical to neurotransmitters
↳ ex. Adrenaline: feeling lingers
Endocrine System
Hypothalamus: brain region controlling pituitary gland
Pituitary gland: secretes many different hormones, some of which affect other glands
Thyroid gland: affects metabolism
Parathyroids: help regulate level of calcium in blood
a
Adrenal glands: inner part helps trigger "flight or flight" response
Pancreas: regulates level of sugar in blood
• "Master gland"
• Located in the core of brain
• Controlled by hypothalamus
1. Growth hormones
2. Oxytocin: bonding
Directs other endocrine glands
Testis/Ovary: Secretes male/female sex hormones
*Feedback system: brain → pituitary → other glands → hormones → body + brain
= reveals nervous and endocrine connection
[ module 11 : Studying the Brain, Older Brain Structures, and the Limbic System ]
• The Tools of Discovery: Having Our Head Examined
1.
2.
3.
4.
5.
6.
7.
No technology that was strong + gentle
Damage to one side caused effects on other side
Damage to back of brain effected vision
Damage to left-front produced speech difficulties
Selectively destroy (lesion) clusters of brain ells: observe results
Stimulate (electrically, chemically, magnetically) various brain parts
Observe single cell or whole brain
Whole Brain Observation Methods
EEG: electrodes placed on scalp measure electrical activity in neurons
MEG: a head coil records magnetic fields from brain's electrical activity (strength and speed)
CT: X-rays of the head generate images that may locate brain damage
PET: tracks where a temporarily radioactive form of glucose goes while brain of person performs a given task
MRI: person's head is put in strong magnetic fields which aligns the spinning atoms of brain molecules
= radio-wave pulse disorients the atoms
= when they return to normal spin, they emit signals that provide detailed picture/map of soft tissues
fMRI: Measures blood flow to brain regions by comparing continuous MRI scans
*provides new insight into how the brain divides its labor
+ [ module 12 : The Cerebral Cortex ]
Hindbrain (brainstem) = Hindbrain Highway
Pons: movement, breathing, sleep, arousal
="bridge to Cerebellum city"
Medulla: unconscious function control (blood circulation, breathing, muscle
maintenance, regulation of reflexes like sneezing/coughing)
= "state troopers" make sure that it is regulated and is functioning
Reticular formation: sleep and arousal
= "reticular rest stop"
Cerebellum: coordinating fine muscle movements and balance
= Cerebellum City
Forebrain = Cerebral City
Cerebrum: sense, think, learn, emotion, consciousness, voluntary
movement
= "Complex Cerebrum City"
Association Area: x motor or
• left + right sides
sensery but o higher mental
↳ connected by corpus callous
functioning
Occipital: see
Prefrontal Cortex: planning, new
Parietal: touch
memory
Temporal: hear
Frontal: movement
Limbic System = Limbic Lane
Hypothalamus: 4F: fight flee feed fuck, controls ANS, w.endocrine
= "To Do list"
Hippocampus: memory
= "hippo on the block"
Amygdala: emotion; esp fear, anger, aggression
= "Ms. Amy.G.D"
Thalamus: all sensory information exc smell
= "Thalamus Compass"
Olfactory: smell
= "Old Smelly Factory"
Midbrain: integrates sensory processes
• The Power of Plasticity
◦ Biology and Experience Interact
Brain constantly changes and builds new pathways = plasticity
◦ Response to Damage
1. Severed brain and spinal cord neurons don't regenerate
2. Some brain functions seem preassigned to specific areas. Certain damage results to certain disabilities.
Compensations do occur though
= ex. blind people can hear better
Self-repair by reorganizing or producing new neurons (neurogenesis)
[ module 13 : Brain Hemisphere Organization and the Biology of Consciousness ]
• Splitting the Brain
↳ severed corpus callous (which connects two hemispheres)
= personality and intellect hardly effected
Ex. HE - ART
*THIS IS SO COOL WHAT THE HECK THE HE goes to RIGHT HEM, ART goes to LEFT HEM, but when they have to
say (LEFT HEM), person would say ART but when they have to point with LEFT hand, person would choose HE.
• Vs. Intact Brain
Right: perceptual, making inferences, helps modulate speech, self awareness
Left: math calculations, speaking
• The Biology of Consciousness
↳ subjective awareness of ourselves and our environment
• Cognitive Neuroscience
↳ the interdisciplinary study of the brain activity linked with our mental process
Can, in limited ways, read mind
= ex. What 10 similar objects you are viewing.
Conscious experience: from synchronized activity across the brain
- if stimulus activates enough brain wide coordinated neural activity- bc strong signals in one brain area trigger
activity elsewhere- it crosses a threshold for consciousness
*consciousness/ awareness requires synchronized activity btw several brain areas
• Dual Processing: The Two- Track Mind
Much of brain's work occurs offstage
= Ex. Consciously: "Its a Dog"
Subprocessing: color, form, movement, distance
= (dual processing)
Blindsight: the ability to respond to visual stimuli without consciously perceiving them. This condition can
occur after certain types of brain damage.
= she could "see" without actual visual recognition
Consciousness sometimes arrives late to the decision making process
Unconsciousness parallel processing is faster than sequential processing
↳at once
↳ one at a time
[ module 14 : Behavior Genetics: Predicting Individual Differences ]
• Genes: Our Codes for Life
Behavior geneticists: study differences and weigh effects of heredity and environment
Chromosome : X, DNA: chain, Genes: segments of DNA, Genome: all of DNA
• Twin and Adoption Studies
◦ Identical vs Fraternal Twins
Identical (monozygotic) twins: from one egg, looks same, have same genes
= differences: placenta, number of copies of genes
Fraternal (dizygotic): from different eggs, looks different, are genetically no more similar than brother and sisters
◦ Separated Twins
Cancels out other contributing variables, can just see which of heredity or environment had a bigger impact
• Biological vs Adoptive Relatives
Shared family environments have little effect on personality, and stability of personality suggests a genetic
predisposition
• Heritability
↳ the extent to which variation among individuals in a group can be attributed to their differing genes
Individual differences (height, intelligence) does not necessarily imply charitable group differences.
= explains why some people are taller than others but not than people from 100 years ago
• Molecular Behavior Genetics
Genetic predispositions and surrounding environments interact: environments can trigger gene activity + genetically
influenced traits can evoke responses from others
Molecular geneticists study the molecular structure and function of genes, including those that affect behavior
Psychologists and molecular geneticists are cooperating to identify specific genes that put people at risk for
disorders
Epigenetic: studies the influences on gene expression that occur without changes in DNA
[ module 15 : Evolutionary Psychology: Understanding Human Nature ]