AP Psych - Unit 2 (A + B): The Biological Bases of Behavior & The Biology of Consciousness

neuron

a nerve (individual) cell; the basic building block of the nervous system; perform 3 primary tasks: receive, integrate, & transmit information

cell body

the part of a neuron that contains the nucleus; the cell's life-support center

dendrites

("tree" in Greek) a neuron's often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body; branchlike fibers that receive information from other neurons or sensory receptors

axon

("axle" in Greek) the neuron extension that passes messages through its branches to other neurons or muscles or glands; a tube-like structure that carries the neural message away from the soma and to other cells (neurons)

myelin sheath

a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next; fatty substance produced by certain glial cells; encases axon; helps insulate, protect, and speed the neural impulse; when the myelin sheath breaks down, messages become inconsistent & slow down which leads to eventual loss of muscle control

glial cells (glia)

cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory; provide support for neurons; deliver nutrients, produce myelin, flush waste & and dead neurons, and influence information processing; influence the generation of new neurons during prenatal development, outnumber neurons 10 to 1; account for 50% of brain's total volume

action potential

a neural impulse; a brief electrical charge that travels down an axon; a very brief shift in the neuron's electrical charge that travels along the axon; begins at the soma; very fast neural messages travel anywhere from 2 mph to 180 mph

threshold

the level of stimulation required to trigger a neural impulse

(absolute) refractory period

(1) in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state; after an action potential, the minimum length of time during which another action potential cannot begin because it has not been fully "reset", the "recharging phase" (1-2 milliseconds), the nerve WILL NOT respond to a stimulus during this period; (2) in human sexuality, a resting period that occurs after orgasm, during which a person cannot achieve another orgasm

all-or-none response/principle

a neuron's reaction of either firing (with a full-strength response) or not firing; if a neuron fires, it will ALWAYS fire at the same intensity (100%) the intensity of the stimulus DOES NOT matter

synapse

("junction" in Greek) the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron, the tiny gap at this junction is called the synaptic gap or synaptic cleft; the action potential CANNOT jump the gap; junction where information is transmitted from one neuron to another (in form of neurotransmitters)

neurotransmitters

chemical messengers that cross the synaptic gaps between neurons; when released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse; a neurotransmitter is a chemical messenger that travels across the synapse from one neuron to the next; transmits information; influence whether the second neuron will generate an action potential or not; neurotransmitters bind to the receptors of the receiving neuron in a lock & key mechanism

reuptake

a neurotransmitter's reabsorption by the sending neuron; neurotransmitters in the synapse are reabsorbed into the sending neurons through the process of reuptake, this process applies the brakes on neurotransmitter action

the nervous system

an extensive network of specialized cells that carries information to and from all parts of the body; brain to the body, face, and internal organs; senses to the brain; the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous system

soma

("body" in Greek) cell body; contains nucleus & chemical "machinery" common to most cells

nodes of ranvier

regularly spaced gaps in the myelin sheath around an axon; ion flow across membrane occurs at the nodes, allowing the signal to move from node to node

terminal branches/buttons

small knobs that secrete (produce and discharge) chemicals called neurotransmitters (chemical messengers)

Alan Hodgkin and Andrew Huxley (1952)

- studied giant squid

- unraveled mystery of neural impulse

- long/big axon & they attached electrodes to it

semi-permeable fluid

allows ions to travel both in & out of the neuron but only at certain times

inside the neuron

ions are mostly negative compared to the outside

outside the neuron

ions are mostly positive compared to the inside

resting potential

a neuron's state when it is NOT firing; an inactive neuron has a stable but negative charge (-70 millivolts), in this state, the neuron IS capable of generating an action potential ready to fire

depolarization

depolarization occurs when positive sodium ions enter the neuron, causing a reversal of the electrical charge from negative to positive, triggering an action potential

repolarization

repolarization occurs when the cell areas return to their resting state of a negative charge as the positive sodium ions are pumped to the outside of the cell & positive potassium ions rapidly leave

excitatory effect

a neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential or "fire", the second neuron is more likely to fire, green light

inhibitory effect

a neurotransmitter effect that makes it less likely that a receiving neuron will generate an action potential or "fire", the second neuron is less likely to fire, red light

agonist

a molecule that increases a neurotransmitter's action; chemical substances that mimic or enhance the effects of a neurotransmitter on receptor sites of the next cell; increases or decreases the activity of that cell, depending on the effect of the original neurotransmitter (excitatory or inhibitory); tricks site to think it is a neurotransmitter

antagonist

a molecule that inhibits or blocks a neurotransmitter's action; a chemical substance that blocks or reduces a cell's response to the action of other chemical or neurotransmitters; block neurotransmitters

acetylcholine (ACh)

characteristics: located at neuromuscular junctions (joints), enables motor movements, memory, and learning

malfunction:

- undersupply: Alzheimer's Disease

- oversupply: severe muscle spasms

psychopharmacology:

- antagonist: curare, botulism

dopamine (monoamine)

(quick rush)

characteristics: involved in voluntary movement, learning, attention, and motivation & reward (pleasure)

malfunction:

- undersupply: Parkinson's Disease

- oversupply: schizophrenia

psychopharmacology:

- agonist: cocaine

norepinephrine (monoamine)

(fight or flight)

characteristics: involved in alertness and arousal

malfunction:

- undersupply: depressive disorders, ADHD (attention hyperactivity disorder)

psychopharmacology:

- agonist: adderall

serotonin (monoamine)

(overall mood)

characteristics: affects mood, hunger, sleep, & arousal; appears to set an "emotional" tone

malfunction:

- undersupply: depression, OCD (obsessive-compulsive disorder)

- eating disorders (varies by person)

psychopharmacology:

- agonist: antidepressants

GABA (amino acid)

(natural tranquilizer, relaxing/slow down)

characteristics: the most common inhibitory neurotransmitter; involved in sleep & the inhibition of movement; aids in the regulation of anxiety

malfunction:

- undersupply: seizure disorders, insomnia

psychopharmacology:

- agonist: alcohol

glutamate (amino acid)

("rev up")

characteristics: the most common excitatory neurotransmitter; involved in learning, memory formation, and the development of the nervous system

malfunction:

- oversupply: migraines, seizures

endorphins

(natural pain-killers)

"morphine within" - natural, opiate-like neurotransmitters linked to pain control and to pleasure

characteristics: natural opiate-like neurotransmitters; involved in pain relief, pleasure, and response to stress

malfunction:

- undersupply: feel more pain

- oversupply: ???

psychopharmacology:

- agonist: morphine

nervous system

the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems; the body's information system

central nervous system (CNS)

the brain and spinal cord; composed of brain and spinal cord, both of which are composed of neurons and glial cells that control the life-sustaining functions of the body, as well as all thought, emotion, and behavior

brain

the true core of the nervous system, interprets information, makes decisions, and sends commands, despite its importance, it would be useless without the spinal cord

spinal cord

a long bundle of neurons; connects the brain to the body; also responsible for fast, lifesaving reflexes; a simple spinal reflex pathway is composed of a single sensory neuron and a single motor neuron, which often communicate through an interneuron

peripheral nervous system (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body; made up of all the nerves and neurons that lie outside the brain & spinal cord; allows the brain and spinal cord to communicate with the sensory systems of the eyes, ears, skin, and mouth and allows the brain & spinal cord to control the muscles and glands of the body; this system can be divided into the somatic nervous system and autonomic nervous system

nerves

bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs

sensory (afferent) neurons

neurons that carry incoming information from the body's tissues and sensory receptors to the brain and spinal cord; carry messages from the body's tissues and sensory receptors inward to the brain & spinal cord for processing

motor (efferent) neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands; carry instructions from the central nervous system out to the body's muscles & glands

interneurons

neurons within the brain and spinal cord; communicate internally and process information between the sensory inputs and motor outputs; neurons within the brain and spinal cord that communicate internally & intervene between the sensory inputs and motor outputs

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles, also called the skeletal nervous system; enables voluntary control of skeletal muscles

autonomic nervous system

more or less automatic (can be consciously overridden, but usually operates on its own), controls organs, glands, & INVOLUNTARY muscles, comprised of the sympathetic nervous system and parasympathetic nervous system

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy; located in the middle of the spinal column, reacts to stressful events and arouses and expends energy, "fight-or-flight" system; dilates pupils, increases heart rate and breathing, and stops digestion & excretion to preserve energy; sympathetic division reacts to stress

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy; located on either side of the sympathetic division, restores the body to normal functioning after arousal, the "rest-and-digest" system; constricts pupils, slows heart rate and breathing, and reactivates digestion and excretion; parasympathetic division brings peace

reflex

a simple, automatic response to a sensory stimulus, such as the knee-jerk response

endocrine system

a system that helps coordinate & integrate complex psychological reactions

hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues

adrenal glands

characteristics:

located at the top of the kidneys, secretes 30 different hormones to deal with stress, regulate salt intake, etc.

pituitary gland

the endocrine system's most influential gland, under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands

lesion

tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue

electroencephalogram (EEG)

an amplified recording of the waves of electrical activity that sweep across the brain's surface, these waves are measured by electrodes placed on the scalp; electrodes placed on the scalp measure electrical activity in neurons; provides an amplified readout of brain waves

magentoencephalography (MEG)

a brain imaging technique that measures magnetic fields from the brain's natural electrical activity; a head coil records magnetic fields from the brain's natural electrical currents

CT scan (computed tomography) (CAT scan)

a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body; x-rays of the head generate images that may locate brain damage

PET scan (positron emission tomography)

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

MRI (magnetic resonance imaging)

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue, MRI scans show brain anatomy; people sit down or lie in a chamber that uses magnetic fields & radio waves to provide a map of brain structure

fMRI (functional MRI)

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans, fMRI scans show brain function as well as brain structure; reveals brain activity and functioning by tracking increased oxygen-laden bloodflow

brainstem

the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions; the lower part of the brain that connects to the spinal cord; the oldest/most basic part of the brain, contains the medulla, pons, & reticular formation, automatic survival functions, sends & receives information

medulla (oblongata)

the base of the brainstem; controls heartbeat and breathing; on top of the spinal cord; the very bottom of the brain; part of the brainstem; involuntary life-supporting functions, respiration, digestion, heartbeat, blood pressure

pons

sits on top of the medulla; larger swelling; links the medulla & cerebellum to the upper portions of the brain (means "bridge"), helps coordinate movement, especially left-right body coordination, influences sleep (ponzzz) and dreaming

reticular formation

a nerve network that travels through the brainstem and into the thalamus and plays an important role in controlling arousal; runs through the middle of the medulla & the pons; in between the ears; controls an organism's level of arousal

cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory; located in the rear of the brain; large & deeply folded structure; "little brain"; helps coordinate muscle movements (w/ assistance from the pons) as well as balance & sense of equilibrium, also plays a role in nonverbal learning and memory

limbic system

neural system (including the amygdala, hypothalamus, and hippocampus) located below the cerebral hemispheres; associated with emotions and drives; a loosely connected network of structures, helps regulate emotion, memory, and motivation

thalamus

the brain's sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla; sits on top of the brainstem; the brain's sensory switchboard, all sense (W/ THE EXCEPTION OF SMELL) pass through the thalamus; send information to proper regions of the cerebral cortex for processing, transmits "replies" to the cerebellum & medulla

hypothalamus

A neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward; directly underneath the thalamus & the pituitary gland; biological drives need for survival & motivational behaviors, FIGHT-OR-FLIGHT; eating & drinking; sexual functions; body temperature; main-link between the endocrine & nervous systems; controls automatic nervous system, monitors/regulates the state of your body, also includes reward centers

hippocampus

a neural center located in the limbic system; helps process storage of explicit (conscious) memories of facts and events; curved structure located within each temporal lobe; wraps around the back of the thalamus; formation of long-term (permanent) memories that are then stored elsewhere in the brain; storage of memories for the location of objects

amygdala

two lima bean-sized neural clusters in the limbic system; linked to emotion; 2 almond-shaped structures; near the hippocampus; involved in emotions connected to survival, responsible for emotional responses to fear & the memory of fear; also associated with emotions of anger and aggression

cerebral cortex

the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center; the outermost part of the brain (gray matter); covers the cerebrum, convolutions allow its large surface area (1.5 feet) to be packed into the limited volume of the skull, contains an estimated 30 billion nerve cells; the wrinkles on the brain are made GYRI (ridges) and SULCI (fissures)

cerebrum

the largest and most complex part of the human brain; includes areas responsible for the most complex mental activities, divided into 2 hemispheres & 4 lobes + association areas

association areas

areas of the cerebral cortex that are NOT involved in primary motor or sensory functions; involved in higher mental functions such as learning, remembering, thinking, and speaking; electrically probing an association area won't trigger any observable response (cannot be mapped like cortexes); found in all 4 lobes

frontal lobe

(Freud) the portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgment; front of the brain; underneath the forehead; largest lobe; advanced cognitive abilities; contains: motor cortex, prefrontal cortex, Broca's area

primary motor cortex

an area at the rear of the frontal lobes that controls voluntary movements; OUTPUT; controls the movement of the body's VOLUNTARY muscles by sending commands to the somatic division of the PNS; cross-wired pattern: motor cortex in the left hemisphere controls the movement in the right side of the body & vice versa

prefrontal cortex (association area)

planning, judgment, personality, memory storage, complex decision-making, and areas devoted to language

Broca's area

helps control language expression; an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech; devoted to the PRODUCTION of speech, allows people to speak smoothly & fluently, directs muscle movements involved in speech

temporal lobe

the portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear; just behind the temples; below the parietal lobe; sound information processing; contains: auditory cortex, Wernicke's area

auditory cortex

processes sensory information from the ears (hearing); inputs to each ear go to both hemispheres, but connections to opposite hemispheres are stronger/faster

Wernicke's area (association area)

a brain area involved in language comprehension and expression; usually in the left temporal lobe; devoted to language COMPREHENSION and expression

parietal lobe

the portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position; top of the head; between the frontal and occipital lobes; registers & processes body touch & movement sensations; general processing, such as mathematical & spacial reasoning); contains: somatosensory (sensory) cortex

somatosensory cortex (sensory cortex)

an area at the front of the parietal lobes that receives and processes body touch and movement sensations; INPUT; register & processes touch, pain, skin temperature, body position in space (everything related to touch), cross-wired pattern: sensory cortex in left hemisphere receives inout from the right side of the body & vice versa

occipital lobe

the portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields; toward the back of the brain; at the base of the cortex; visual information processing; contains: visual cortex

visual cortex

processes sensory information from the eyes (vision); NOT contralateral: the left visual cortex receives information from BOTH eyes that come from the right field of vision

plasticity

the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience

- plasticity is greatest in childhood

- ex: bad limbs, deafness, blindness

neurogenesis

- the formation of new neurons

- although the brain often attempts self-repair by reorganizing existing tissue, it sometimes attempts to mend itself through neurogenesis

- producing new neurons

corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them; although the brain is divided into two hemispheres, it works as a single entity; continuous communication via the corpus callosum; historically, the left brain has been considered dominant, while the right brain has been labeled subordinate, but now we know that BOTH play important roles

split brain (splitting the brain)

- a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them

- a procedure in which the brain's hemisphere are isolated by cutting the corpus callosum

- neurosurgeons Philip Vogel & Joseph Bogen (1961) tried to spot epileptic seizures and found that split-brain patients are "normal" and they provided the key to understanding the complementary functions of the brain's hemispheres

- Michael Gazzaniga & Roger Sperry (1964/1967) performed experiments on split brain patients and helped show hemispheric lateralization (specialization of function in each hemisphere)

hemispheric lateralization

the specialization of function in each hemisphere

left hemisphere

language is the best example of a clear-cut difference in function between the brain's hemispheres; for most people, language functions are in the left hemisphere

- reading, writing, speaking, arithmetic reasoning and understanding, and logic

right hemisphere

(facial & spatial)

- housing the brain's spatial abilities, perception, dimension, facial recognition, etc.

- associated with creativity, imagination, intuition, emotional processing, sense of self/self-awareness, and inference making

- ex: connections between words

phantom limb syndrome

the perception of sensations, usually including pain, in a limb that has been amputated

- the brain continues to receive messages from nerves that originally carried impulses from the missing limb

- after amputation, these nerves invade the brain area vacated by the missing limb

behavior genetics

the study of the relative power and limits of genetic and environmental influences on behavior

- nature vs. nurture

- heredity (nature) & environment (nurture)

heredity

the genetic transfer of characteristics from parents to offspring (nature)

environment

every nongenetic influence, from prenatal nutrition to the people and things around us (nurture)

chromosomes

- threadlike structures made of DNA molecules that contain the genes

- strands of DNA (deoxyribonucleic acid) that carry genetic information located in the nucleus of every human cell

- humans have 46 chromosomes, 23 from each parent

DNA

(deoxyribonucleic acid) a complex molecule containing the genetic information that makes up the chromosomes

genes

the biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein

- DNA segments

- key functional units in hereditary transmission

- can be active (expressed) or inactive

- environmental events "turn them on"

- like chromosomes, they operate in pairs, one in each pair coming from each parent

genotype

a person's fixed genetic makeup; determined at conception and fixed forever

phenotype

the ways in which a person's genotype is manifested in observable characteristics; may change over time

- most of our traits are influences by many genes