UNIT 1 AP PSYCH REVIEW
BIOLOGICAL BASES OF BEHAVIOR
Nature vs. Nurture
NATURE:
Heredity, genes
Darwins evolutionary approach
Theory of evolution: Evolution happens through natrual selection and heredity and specific genes/traits help organisms survive
NURTURE:
Family life, environmental scenarios
BELIEFS:
Eugenics:
Belief in improving the genetic quality of the human population by selectively breeding for desriable traits
Discouraging reproduction among those with traits considered undesirable
Epigenetics:
How the environment and a person’s behavior affect a person’s genes and how they work.
Study of changes in how genes are turned “on” or “off” without changing the DNA sequence itself.
These changes can be influenced by the environment (diet, stress, toxins) and can sometimes be passed down.
Can explain why identical twins showcase vastly different physical and mental differences
PLASTICITY:
Refers to the brain’s ability to change and adapt as a result of experiences
Allows brain to be flexible and adapt to changing expereinces
Strengthening/Weakening nueral connections
NUERAL SYSTEMS
Central Nervous System (CNS):
Brain and spinal cord
Sends out orders to the body
Peripheral Nervous System (PNS):
Consists of nerves that branch off from the brain and spine
Connects the CNS to all of the bodies organs and muscles
PARTS OF PNS
Somatic Nervous System (Skeletal Nervous System or SNS): Includes your 5 senses and skeletal muscle movements. These movements happen consciously and voluntarily
Autonomic Nervous System: Controls involuntary activities, this is what makes sure your hear keeps beating, your stomach keeps digesting, and you keep breathing
Can be divided into two parts:
Sympathetic Division:
Mobilizes body and gets it ready for ACTION, making your heart beat faster, your eyes dilate, and increases your breathing
Fight or flight
2.Parasympathetic Divison:
RELAXES the body, slows heart rate, increases digestion, and helps focus on saving or STORING energy
Rest and Digest
Usually after highly energetic or adrenaline moment
NERVOUS SYSTEMS
Afferent Nuerons (Sensory Nuerons)
Afferent APPROACHES the Brain
Sends signals from the sensory receptors to the central nervous system
Efferent Nuerons (Motor Nuerons)
Efferent EXITS the brain
Send signals from the central nervous system to the peripheral nervous system
2 COMMON TYPES OF NUERAL CELLS
Provide:
Structure
Insulation and Communication
Waste Transportation
Basis of the nervous system
Building blocks of all behavior and mental processes
1.Glial Cells
Most abundant cells in nervous system
Support nuerons through protection
Provide nuerons with nutrients
DO NOT PROCESSES INVORMATION and DO NOT SEND SIGNALS
2.Nuerons
Basic unit of the nervous system
Communicate with each other through electrical impulses and chemical signals to SEND INFORMATION througout nervous system
3 TYPES OF NEURONS IN SPINAL CORD
Work together to create a REFLEX ARC
REFLEX ARC: Nerve pathway that allows body to respond to a stimulus without thinking. Your reflexes! Helps protect us
Ex. Scenario: You touch a hot stove
1.Sensory Nuerons
Afferent Nuerons
You sense something hot, skin receptors send a signal through sensory nuerons to spinal cord
2.Internnuerons
Nuerons within the brain and spinal cord
Signal is recieved in internuerons which they then communicate internally and connect sensory neurons to motor neurons within the CNS
3.Motor Nuerons
Efferent Nuerons
Signal is recieved to motor nuerons and motor nuerons travel through the PNS (pheripheral nervous sytem) which then connects to your muscles to move your hand away from the hot surface
PROCESS OF NEURAL TRANSMISSION
In order for nueron to recieve a message, they need to recieve enough stimulus to create an ACTION POTENTIAL
Depolarization: Stimulus needs to be strong enough to meet the threshold of a nueron to trigger action potential
ACTION POTENTIAL: Nueron fires and sends a signal down the axon (part of the nueron) and sends a signal to other nuerons in the nervous system who repeat the same processes
Positively charged ions on one side of the axon, negatively charged on the other side during Action potential. Ions appear after crossing the cell membrane to appear outside the axon
PERMEABILITY: Some ions travel outside the cell memberane more easily
When nueron is not sendind a signal, it has more negative ions on the inside than the outside, known as RESTING POTENTIAL
Repolarization: After sending the signal nueron returns back to resting potential. More positive ions go outside and more negative ions go inside cell memberane
When signal is moving down nuerons axon, nueron cannot respond to any other stimulus, known as the REFRACTORY PERIOD
REFRACTORY PERIOD: Time where cell cannot fire and needs to wait until repolarization and resting period
Signal makes its way to the synapse, located at the end of one nueron and the begining of another, connecting the two. A GAP that the synapse fills, which helps it transmit the signal to the next nueron
CHEMICAL SYNAPSES: Use nuerotransmitters (chemical messengers) to send messages through the nervous system
ELECTRICAL SYNAPSES: For messages that need to be sent quickly
REUPTAKE: Process of taking excess nuerotransmitters left in synaptic gap. The sending nueron (the begining one) reabsorbs excess nuerotransmitters if there are excess from the second nueron
Depending on which receptors nuerotransmitters bind to, the nueron will become exited or inhibited (activity is reduced)
Excitatory Nuerotransmiters: Increase likelihood that nueron will fire an actoin potential, through the depolarization processes in the postsynaptic nueron (neuron that receives the signal at a synapse)
Inhibitory Nuerotransmitter: Decreases the likelihood that a nueron will fire an action potential. Hyperpolarization occurs: Inside of the nueron becomes more negative, moving nueron furthre away from the threshold needed for action potential.
* If processes gets disrupted, can lead to NUEROLOGICAL DISORDERS
1. Multiple Sclerosis: Myelin sheat covering the axon is damaged, disrupting electrical signals. Symptoms like muscle weakness, coordination problems, Fatigue
2.Myasthenia Gravis: Autoimmune disorder affecting the communication between nerves and muscles, block or destroy acetylcholine receptors. Nerve signals can’t effectively trigger muscles, leading to muscle weakness and fatigue.
NUEROTRANSMITTERS
1. Acetylcholine: Enables muscle action, learning, and helps with memory
2. Substance P: Helps with transmitting pain signals from the sensory nerves to the CNS
3. Dopamine: Helps with movement, learning, attention, and emotion
4.Serotonin: Impacts an individuals hunger, sleep, arousal, and mood
5.Endorphins: Help with pain control and impact individuals pain tolerance
6.Norepinephrine: Increases blood pressure, heart rate, and alertnesses, and helps with body’s fight or flight response
7.Glutamate: Long term memory and learning
8.GABA: Helps with sleep, movement, and slows down your nervous system
HORMONES
1.Adrenaline: Also epinephrine, helps with body’s response to high emotional situations, helps form memories, expands air passages in the lungs, redistributes blood to muscles, and is involved in body’s fight or flight
2.Leptin: Energy balance by calming hunger. Signals to the brain that the body has enough stored fat, reducing a person apetite
3.Ghrelin: Hunger hormone, signals to the brain we’re hungry, promote the release of growth hormones
4.Meletonin: Sleep hormone, produced by pineal gland, regulates sleep-wake cycles
5.Oxytocin: Produced hypothalumus and released in pituitury glands. Love hormone, promoted feelings of affection and emotional bonding
*Hormones are part of the ENDOCRINE SYSTEM
Sends hormones throughout the body’s blood to regulate different biological processes
DRUGS
Agonist Drugs: Incerase the effectiveness of a nuerotrasnmitter. AMPLIFIES or increases production of nuerotransmitter. Anti-anxiety medications (incraeases nuerotransmitter GABA)
Antagonist Drugs: Decreases the effectiveness of a nuerotransmitter. Medication for schzoprenia: Blocks dopamine receptors
TYPES OF PSYCHOACTIVE DRUGS
1.Stimulunts
Excite, promote nueroactivity
Give a person energy
Caffeine, Nicotine, and cocaine
2.Depressants
Reduce nueral activity
Drowsiness
Muscle Relaxation
Alchohal, sleeping pills
3.Hallucinagins
Marihuana, LSD
Hallucinate
4.Opiods
Are a depressant, but own category bc of its addictive nature
PAIN RELIEF
Oxytocin, morphine, heroin
REGIONS OF THE BRAIN
1.Hindbrain
Located at the bottom of the brain
2.Midbrain
Located in the center above hindbrain
Visual and auditory information
Motor Control
Integrating sensory motor pathways
3.Forebrain
Sitting at the top
STRUCUTRES OF THE BRAIN
1.Spinal Cord: Connecting your brain to the rest of the body, allows nuerons to send messages
2.Brain Stem: Includes midbrain, medula, and pons and controls automatic functions
Medula: Regulation of persons cardiovascular and respiratory system. Takes care of automatic functions
Pons: Connects medulla with cerebullum and helps coordinate movement. SLEEP AND DREAMS
Reticular Activiating System: Network of nerve cells and fibers within the brain stem. Regulation of arousal, alertness, and sleep-wake cycles. Stimulate other brain structures when somehing happens
3. Cerebellum: Coordinating voluntary movement, posture and balance, refining motor skills, and cognitive functions. LITTLE BRAIN
4.Cerebrum: Located in the forebrain, deals with complex thoughts. Covered by the cerebral cortex which are billions of nerve cells, dividing into two parts which is connected throught corpus callosum, allowing hemipsheres to communicate with each other
BRAIN LATERALIZATION: DIFFERING FUNCTIONS OF RIGHT/LEFT HEMISPHERES
Right Hemisphrere
Spacial Concepts
Facial Recognition
Direction
Left Hemisphere
Language
Broca’s Area: Language production, controlling the movement of muscles involved in speech. If this part is damaged, individual will expereince Broca’s Aphasia, lost in ability to produce language. Can understand speech, but will struggle to speak
*SPLIT BRAIN PROCEDURE: Cuts the corpus callosum, so they can no longer communicate
*Researchres test for CORTEX SPECIALIZATION, to show how cortex is specialized for different fucntions
*Lesion Studies: Doctors will destroy specific parts of the brain to gain insights into different functions of the brain
Quick way to remember:
Cerebrum = “thinking & doing”
Cerebellum = “coordination & balance”
5.Thalamus: Sensory information from sensory organs for everything but smell. RELAY STATION, relays appropirate infromatoin to the cerebrum cortex
6.Limbic System: The limbic system is a group of brain structures that work together to control emotion, memory, and motivation.
7.Hypothalamus: Keeps your body balanced and homeostasis
8.Pituitary Gland: Master Gland, produces and releases hormones
4 LOBES
1.Frontal Lobe
Higher level thinking
Prefrontal Cortex: Deals with foresight, judgement, speech and thoughts
Motor Cortex: Voluntary Movement. Left motor cortex controls movement on right side, and right motor cortex controls movement on the left side
2.Occipital Lobe
Visual information processing
Primary visual cortex
3.Parietial Lobe
Sensory Information
Somasensory Cortex: Processes touch and senses and body position
4.Temporal Lobe
Auditory Information
Recognizing faces
Hippocampus: Learn and form memories, NOT WHERE MEMORIES ARE STORED
Amygdala: Emotions
Auditory Cortex: Processes different sounds and language
WERNICKE’S AREA: Damage → you can speak fluently, but your speech may be meaningless or nonsensical and you may not understand language well: Wernicke’s aphasia
Broca’s area vs. Wernicke’s area
Broca’s area
Responsible for speech production (speaking and forming sentences)
Damage → you understand language but struggle to speak fluently
Wernicke’s area
Responsible for language comprehension (understanding spoken and written language)
Damage → you can speak fluently, but your speech may be meaningless or nonsensical and you may not understand language well
Quick way to remember:
Broca = “builds speech”
Wernicke = “understands speech”
NUEROPLASTICITY: Abilility of the brain to change and modify itself
GAINING INSIGHTS THROUGH IMAGING
1.EEG
Allow researchers to record electrical signals from nuerons firing
2.FMRI
Show metabolic functions (converting food into energy through cells)
SLEEP
*When sleeping, we’re still concious
* Cognitive Nueroscience: How brain activity is linked with cognitiion
*CIRCADIAN RHYTHM: BIOLOGICAL CLOCK
STAGES OF SLEEP
1.NREM Stage 1
Light Sleep
Body starts to relax and mind starts to slow
2.NREM Stage 2
Sleep spindles
Short bursts of rapid brain activity
Thought to help with memory consolidation and blocking out external noise
K-complexes
Large, single spikes of brain activity followed by a slow wave
Help protect sleep by suppressing responses to sudden sounds or stimuli
3.NREM Stage 3
Growth hormones produced
Sleepwalking/sleep talking
4. REM SLEEP (rapid eye movement)
External muscles are paralyzed
expereince Dreams
If REM sleep is continuosly disturbed, individual may expereince REM Rebound: Spending more time in REM sleep
DREAM THEORIES
1.Activation-Synthesis Theory
Dreams are the brain’s way of making sense of random neural activity during sleep
2.Consolidation Theory
Dreams help process and strenghten our memories and expereinces
Memory consiladtion
3.Restoration theory
Sleep because we get tired from daily activites and we sleep to restore our energy
SLEEPING TROUBLES AND DISORDERS
1.Insomnia: Struggle to fall or stay asleep
2.Sleep Apnea: Hard time with sleeping since they struggle wit BREATHING]
3.REM Sleep Behavior Disorder: Person acts out their dreams, even though body is normally paralyzed during sleep
4.Somnambulism: Sleep walking
5.Narcolepsy: Random sleep attacks
SENSATION
SENSORY ADAPTATIN: Stimulu that is continuounant and doest change. Such as lightin a candle, but you cannot smell it anymore. GETTING USED TO AN UNCHANGED STIMULUS
Habituatoin: When you are repeatedly exposed to a stimulus and start to have a reduced rsponse to the stimulus. First time a person does drugs, they might get a strong reaction, but then they need more and more as time goes on to gain that initial response. LEARNING FROM A REPEATED STIMULUS
DIFFERENCE THRESHOLD: Minimum change between two stimuli that causes the individual to detect the change
Weber's Law: The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).
Synesthesia: One sense is experienced through another. Might see colors when experiecing music
Accommodation: process by which the eye's lens changes shape to focus images of near or far objects on the retina.
THE EYE
Retina: Made up of layers of light sensitive receptors. Convert light into nueral impulses for the brain to process what the eye is seeing
Nueral impulses travel from the OPTIC NERVE to the eye
BLIND SPOT: No photo receptors, so you cannot see anything there
TYPES OF PHOTORECEPTORS
Rods: Allow you to see in dim light, but do not provided color
Cones: see fine detials, help you see color, clear vision
THEORIES EXPLAINING COLOR VISION
Trichromatic Theory
Our brain mixes signals from red, green, and blue cones to produce all perceived colors.
Opponent Processing Theory:
Color is processed as competing pairs of opposites in the visual system
Neurons are activated by one color in a pair and inhibited by the opposite color
This is why you can’t see “reddish-green” or “bluish-yellow” at the same time
Explain AFTER-IMAGES, staring at an image for a long time and seeing the opposite color after
DAMAGE TO THE BRAIN (OCCIPITAL LOBE)
Prosopegnosia: Face blindness. Damage to occipital and temporal lobes
Blindsight: Damage to primary visual cortex. Appear to be blind in certain areas
SOUND:
Amplitude: Greater amplitude means more aenergy and loudness of the sound
Frequency: High frequency have higher pithces, while low frequency have low pitches
SOUND LOCALIZATION: Process by which the brain determines the orignin of sounds in our environment
SOUND THEORIES
Place Theory: Certain hair cells respond to certain frequencies. Pitch is determined by where on the cochlea the sound wave causes vibrations. Good for high pitch sounds
Frequency Theory: Pitch is determined by how fast neurons fire, not where they fire. Explains how we perceive low-pitched sounds.
Volley Theory: When sounds are too fast for a single neuron to fire alone, groups of neurons take turns firing in a coordinated “volley” pattern to match the sound’s frequency.
DEAFNESS
Conductive deafness: problem in outer/middle ear that blocks sound from reaching the inner ear.
Sensorineural deafness: damage to the inner ear or auditory nerve, so sound isn’t properly processed or sent to the brain.
CHEMICAL SENSORY SYSTEM
NOSE: SMELL
Olfactory receptors: Sensory neurons in the nose that detect smell molecules (odorants) in the air
Pheromone: is a chemical signal released by one organism that affects the behavior or physiology of another organism of the same species. Detected through olfactory system
GUSTATION: TASTE
Unami- Savory. PROTIEN
Oleogustus: FATS
Papilae: Taste buds
TOUCH & Pain
Mechanoreceptors: Sensory receptors located in skin to respond to PRESSURE
Thermoreceptors: Receptors in skin that respond to TEMPERATURE changes
Nociceptors: Located in dermis (below the skin) and are PAIN receptors
GATE CONTROL THEORY: spinal cord has a “gate” that can either allow or block pain signals from reaching the brain.
If the gate is open → you feel more pain
If the gate is closed → pain signals are reduced
This explains why rubbing an injured area can lessen pain (touch signals help close the gate)
Phantom Limb Sensation: person feels that a missing or amputated limb is still there, sometimes including pain, itching, or movement feelings.
BALANCE AND MOVEMENT: CEREBELLUM PLAYS A MAJOR ROLE
Vestibular Sense: Maintain your balance through sense from inner ear
Kinesthesis: Sense that provides information about hte position and movement of individual body parts. Where are my limbs in space? How am i moving?
Proprioreceptors: Receptors located in muscles so brain gets understanding of our position and movement of our limbs. Helps with KINESTHESIS