AP PSYCH UNIT 1 REVIEW

Nature vs Nurture

• Charles Darwin’s influence -> Natural selection

• John B. Watson -> Nurture

Evolutionary Psychology - The area of psychology that looks at how human behavior, trait characteristics and physical development have evolved over time

• Founded by Charles Darwin

Natural Selection - a process in evolution where organisms with behavioral and cognitive traits that help them survive and reproduce are more likely to see them passed on genetically to their offspring

Adaptation -  how living things change over time to better fit their environment 

Eugenics -  application of evolutionary ideas to human breeding 

• Francis Golton 

• The science of improving the human population by controlled breeding to increase the occurrence of desirable heritable characteristics

Behavior Genetics - the study of the influences and limitations of genetic and environmental influences on behavior

Environment - refers to all the non-biological, external factors that influence one’s life, such as family, friends, education, geographical location, cultural norms, and individualized experiences

Heredity - the process through which genes are passed from one generation (parents)to the next (children). The way physical and some behavioral traits are passed down through generations

Genes - the biochemical units of heredity

• Biological instructions

• Genome - complete set of genes/instructions for making an organism

DNA - the material that carries all the genetic information about how a living thing will look and function

• Made up of a long chain of molecules and contains the genes that make you who you are

• Primarily located in the nuclei of an organism’s cells 

Minnesota Study of Twins Reared Apart

Monozygotic (identical twins) - twins who developed from a single fertilized egg that split in two, creating genetically identical organisms

Dizygotic (fraternal) twins - twins that develop from separate fertilized eggs

• Genetically no closer or similar in nature than ordinary siblings

Colorado Adoption Progress - a longitudinal study initiated in 1975 to explore the roles of genetics (nature) and environment (nurture) in human development

• Key Findings

  • As children grow, their cognitive abilities become more similar to their biological parents than to their adoptive parents

  • Personality traits showed moderate heritability, but environmental factors also played a significant role, especially in early childhood

  • Shared family environment had a more substantial impact on children’s behavior in early childhood, but this influence wanes over time, as genetic factors take precedence in shaping behavior during adolescence

Nervous system - acts as the body’s speedy electrochemical communication center

• Transmits signals from the brain to the rest of the body and consists of all the nerve cells of the peripheral and central nervous systems

• Central nervous system - made up of the brain and spinal cord

  • Spinal cord - the long thin network of nerves that extends from the brainstem to the lower back

  • Brainstem - connects the spinal cord with the brain and includes the medulla

    • IF THE BRAIN STEM IS DAMAGED, PARTICULARLY THE MEDULLA, MOST LIKELY WILL LEAD TO DEATH

• Peripheral nervous system - made up of nerves that branch off from the spinal cord and extend to all parts of the body

Neurons - individual cells in the nervous system that relieve, process, and transmit information

Sensory (afferent) Neurons- detects light, sound, odor, taste, pressure, and heat, and send messages about those things to the brain 

• Afferent approach the brain

Motor (efferent) neurons - transmit messages from the brain to the muscles to generate movement

• Efferent exit the brain

Interneurons - neurons within the brain and spinal cord that communicates with one another and serve as a connection between sensory and motor neurons

• Plays a key role in connecting neurons in the spinal cord to neurons of the brain

• Only found in the central nervous system 

Reflex arc - when an interneuron connects sensory neurons to motor neurons directly, without going through the brain to make the connection

• ex) touching something hot and removing your hand immediately

Soma - this is the cell body, which contains the nucleus and the chemicals that make the cell function

Dendrites - these are the parts of the neuron that receive information from other cells and sensory organs

Axons - these are the long, thin fibers that transmit signals away from the soma to other neurons (and muscles and glands)

Myelin Sheath - insulating material that encases the axons, helping to speed up transmission of the signals/messages sent along the axons

• A glial cell known as the Schwann cell helps create the MS

Axon terminals - the clustered end of an axon, which secretes neurotransmitters

Neurotransmitters - chemical messengers that activate neighboring neurons

Synapse - the junction where the information of one cell is passed on to, or received by, another cell

• Small space between neurons (not actually apart of the neurons)

Action potential - a neural impulse/electrical charge that travels down the axon, away from the cell body

Glial Cells - most abundant cells in the nervous system (support network)

• Support and structure: holds neurons in place 

• Protect neurons: insulate with myelin 

• Provides nutrients

• Repair and restore neuron function

• Waste management (trim and eliminate dead neurons)

• Regulate neurotransmitters

Action potential - brief neural impulse/electrical charge that travels down the axon

• Occurs when stimulated by our senses, or when our neurons receives a strong signal from neighboring neurons

Threshold - the strength of the impulse required to trigger an action potential / the level of stimulation required to trigger a neural impulse

Refractory period - a brief pause that occurs after a neuron fires 

• Occurs after the threshold and action potential takes place

All or none response - the activation of neural firing, meaning whether the neuron fires or doesn’t fire

• If threshold isn’t met, there’s no firing of the neuron

Reuptake - the process where neurotransmitters are reabsorbed by the sending neuron

Presynaptic Neuron - the neuron sending the transmitters to the postsynaptic neuron

Postsynaptic neuron - receiving the transmitters sent by the presynaptic neuron

Excitatory neurotransmitters - chemicals produced by the body to transmit signals between neurons & promotes the generation of active potentials in the receiving neuron

• Glutamate - most abundant excitatory neurotransmitter

Inhibitory neurotransmitters - neurotransmitters that decrease the likelihood of a neuron firing an action potential + chemicals have a calming or inhibitory effect on neural activity

• GABA and serotonin

Agonist - molecule (drug) that binds to a receptor, increasing a neurotransmitter’s action. 

• ex) Opiates/think of it like a person who holds a door open to let more people pass through before it closes

Antagonist - a molecule that decreases (inhibits) or blocks the effects of a neurotransmitter

Endocrine system - the body’s slow chemical communication system

• Made up of glands and fat tissue that secrete hormones into the bloodstream

• Endocrine + nervous system = maintaining homeostasis

Pituitary Gland - descends from the hypothalamus at the base of the brains, and acts in close association with it.  

• “Master gland” -> messenger hormones control all the other glands of the endocrine system

Acetylcholine - enables muscle action, learning and memory

• excitatory neurotransmitter

• Undersupply: risk of developing alzheimer’s disease and myasthenia gravis

Serotonin -  impacts hunger, sleep, arousal, and mood

• Inhibitory neurotransmitter

Dopamine - influences movement, learning, attention, emotion, and motivation

• oversupply: schizophrenia, obesity, and addictive behaviors

• undersupply: tremors, decreased mobility, and Parkinson’s disease

• acts as both excitatory and inhibitory neurotransmitter

• Specific effect depends on location in the brain, types of neurons it acts on, contributing to its complex role in functions such as movement, motivation, reward, and mood regulation

GABA - major inhibitory neurotransmitter 

• undersupply: seizures, temores, and insomnia

Glutamate - major excitatory neurotransmitter, plays a key role in memory

• oversupply: overstimulate the brain; headaches, migraines, and seizures

Endorphins -  the body’s natural opioid-like neurotransmitters linked to [ain control and pleasurable feelings of euphoria

• oversupply: opioid drugs can suppress the body’s natural production of endorphins -> decreased pain tolerance

Substance P -  involved in immune response and the perception of pain

Oxytocin - hormone secreted into the bloodstream by the pituitary gland

• referred to as the love hormone

• responsible for producing positive emotions

Melatonin - the sleep hormone, produced by the pineal gland and helps with the regulation of your sleep cycles

Epinephrine & Norepinephrine - produced by the adrenal glands as part of our fight or flight response and an increase in the heart rate, blood pressure, and blood sugar levels

Psychoactive drugs - chemical substances that alter the brain and cause changes in perceptions and moods

Substance use disorders - disorders characterized by continued substance use despite the development of life disruptions resulting from the use of substances

classifications - of psychoactive drugs includes: depressants, stimulants, and hallucinogens

Tolerance - the diminishing effect with regular use of the same dose of the drug, requiring the user to take larger doses before experiencing the drug’s effect

Addiction - commonly used term for compulsive substance use and dysfunctional behavior patterns that continue despite harmful consequences

Withdrawal -  both the discomfort and distress that follow, when one discontinues the use of , or engagement in, an addictive drug or behavior

Peripheral Nervous System - composed of all of the nerves outside the brain and the spinal cord

• Connects the CNS to the rest of the of the body, enabling communication between and among the brain, spinal cord, muscles, organs, and sensory receptors

• Subdivided into the SNS and ANS

Somatic Nervous system - made up of all nerves that connect to voluntary skeletal muscles and sensory receptors 

• Nerves carry information from our sensory organs and receptors in the skin, muscles, joints, to the central nervous system

• Afferent Nerve Fibers - carry information from the CNS to the PNS

• Efferent Nerve Fibers - motor nerve fibers that carry information out of the CNS to the PNS

Autonomic nervous system - made up of nerves that connect to the heart, blood vessels, smooth muscles,and glands

• controls automatic, involuntary functions 

• Divided into 2 branches:

  • Sympathetic division - creates the fight or flight response 

  • Parasympathetic division - conserves bodily resources, saving and storing energy, ‘rest and digest’

Phineas Gage*

• 1848, working on a railroad when an iron rod was driven through his skull from an explosion

• Survived the accident, but severely damaged the frontal lobes of his brain -> caused personality changes and emotional disturbances 

• Coughed up a piece of his brain

• First scientific evidence that indicate the frontal lobes of the brain has something to do with personality and emotional reactivity

Paul Broca*

• 1865, concluded that damage to a specific region of the left, frontal lobe led to a type of aphasia develops

  • Difficulty with speech production non-fluent aphasia/Broca’s Aphasia

• Comprehension

Carl Wernicke*

• 1874, concluded that a damage to a specific region of the left temporal lobe led to the development of a type of aphasia that has come to be known as Wernicke’s aphasia 

• no comprehension

Brain lateralization is left and right hemisphere

Neuroimaging Techniques

• EEG (electroencephalogram) - Electrodes placed on scalp, measure electrical activity in neurons

• MEG (magnetoencephalography) - A head coil records magnetic fields from the brain’s natural electrical currents

• PET (positron emission tomography) - Radioactive glucose is used to evaluate the brain’s activity and blood flow, tracking specific regions of the brain, and detailing which areas are active at any given moment

• CT (computed tomography) - X-rays of the head generate images that may locate damage to the brain

• MRI (magnetic resonance imaging) - Provide detailed images of the body and brain by using magnetic impulses

• fMRI (functional magnetic resonance imaging) - Measures blood flow and oxygen flow in different parts of the brain. It is scanning brain activity, or function, by comparing continuous MRI scans

Lesion Studies on the brain - A lesion study of the brain involves deliberately creating brain injuries, or lesions, in order to understand the functions of specific brain regions

• Mainly conducted on animals

• Surgical removal, electrical stimulation, or chemical treatment of specific sections of the brain are ways in which researchers can better understand brain functioning.

Hindbrain

• *Cerebellum - controls muscle tone and balance

  • coordination center, helps the body remember how to perform motor actions

• *Medulla Oblongata - controls involuntary (automatic) actions like breathing digestion, heart rate, and blood pressure, AKA cardiovascular and respiratory systems

• Pons - contains bundles of nerves that help with voluntary movements (ex. sleeping & dreaming), connects the medulla with the cerebellum

Midbrain

• Tectum serves as the midbrain’s roof & the tegmentum as its floor - works together and governs visual and auditory reflexes

• Reticular formation - a network of nerves that goes from the midbrain down through the brain stem and is involved in arousal and the sleep cycles

  • Damage to this area, leads to coma

• Reticular activating system - reticular formation & network of nerves that extend out to the thalamus

Forebrain

• Cerebrum: Largest part of the brain -> responsible for voluntary functions/higher-order brain functions

  • Cerebral Cortex: outermost layer of densely packed neurons of the cerebrum and is often referred to as the gray matter, because neurons of the cerebral cortex are not encased in myelin sheaths, therefore giving them a grayish appearance

    • Corpus Callosum: arch-like bundle of nerve fibers that extends from the front of the brain to the back and connects the 2 cerebral hemispheres

      • Connects two cerebrals hempispheres

  • allows and regulates complex thoughts and behaviors

• Limbic System: associated with emotions and drives

  • Thalamus - relays sensory information; receives and directs sensory information from visual and auditory systems of the brain

  • Hippocampus - involved in processing and integrating memories, helps form and create new memories to store memories but DOES NOT STORE 

    • If damaged, cannot learn new material

  • Amygdala - connected to our expressions, sends signals to hypothalamus when the fight or flight system to be activated

  • Hypothalamus - Directs the activation of the sympathetic nervous system for fight or flight response & the endocrine system by regulating the pituitary gland

    • controls our bodily temperature and water balances

    • Vital in maintaining homeostasis

    • Researchers Olds and Milner (1954) discovered in studies with rats that this region of the brain is linked to emotion and rewards

    • Broken down into:

      • Lateral hypothalamus - sends signals to eat when we are hungry (hormone Ghrelin)

      • Ventromedial hypothalamus - sends signals to stop eating when we are satiated (hormone Leptin)

Frontal Lobe - part of the Cerebral Cortex, located behind the forehead

• Includes the prefrontal cortex -> regulates foresight, speech, judgment, memory, BROCA’S AREA and the MOTOR CORTEX

  • Motor Cortex - controls voluntary movement and is arch shaped and goes from ear to ear in the back of the frontal lobe

  • Motor Homunculus - visual representation of the amount of brain tissue dedicated to the movement of specific body parts

Parietal lobe - part of the cerebral cortex that sits at the top of the head, just behind the frontal lobe

• Primary function = to receive sensory information

• Somatosensory Cortex - located in the front area of the parietal lobe & parallel to motor cortex 

Occipital lobe - located behind the parietal lobe at the back of the head

• Primary function: to regulate vision -> Visual cortex 

  • Visual Cortex - receives visual information from the eyes and relays it to other areas in the cerebral cortex to make sense out of what is being viewed

    • The lefts side of the Visual Cortex interprets information from the left side of each eye, which in turn is reading the Right Field of Vision

    • The right side of the Visual Cortex, interprets information from the right side of each eye, which in turn is reading the left field of vision

Temporal Lobe - part of the cerebral cortex that is located above the ears in each hemisphere of the brain

• Primary function: process hearing

• Wernicke’s area of comprehension

• Angular Gyrus - helps with processing and understanding the information we read and hear

• Auditory Cortex - located in the temporal lobe & processes hearing

  • Processes information from opposite sides of the head. Left AC processes information from the right-hand side of the body; Right AC processes information from the left-hand side of the body.

Association Areas - areas of the cerebral cortex that are not involved in primary motor or sensory functions, involved in higher mental functions

Neurogenesis - the production of new neurons

Neuroplasticity - the ability of the brain to form new neurons and reorganize neural pathways (especially during childhood)

• Primarily the result of learning & experiencing something new -> damages pre existing synaptic pathways

Alcohol - depressant, Initial high, followed by relaxation & disinhibition, Depression, memory loss, organ damage, impaired reactions

Heroin - depressant, Rush of euphoria, relief from pain, Depressed physiology; loss of natural endorphin production

Caffeine - Stimulant, Increased alertness and wakefulness, Anxiety, restlessness, insomnia in high doses

Nicotine - Stimulant, Arousal and relaxation, sense of well-being, Heart disease, cancer

Cocaine - Stimulant, Rush of euphoria, confidence, energy, Cardiovascular stress, suspiciousness, depressive crash

Methamphetamine - Stimulant, Euphoria, alertness, energy, Irritability, insomnia, hypertension, seizures

Ecstasy (MDMA / methylenedioxymethamphetamine) - Stimulant; Mild Hallucinogen, Emotional elevation, disinhibition, Dehydration, overheating, depressed mood, impaired cognitive and immune functioning

LSD (lysergic acid diethylamide) - Hallucinogen, Visual “Trip”, Risk of panic attacks

Marijuana (delta-9-tetrahydrocannabinol, THC) - Mild Hallucinogen, Enhanced sensation, relief of pain, distortion of time, relaxation, Impaired learning and memory, increased risk of psychological disorders