AP Psychology Unit 2: Introduction to the Brain

Phrenology

Study of the skull by feeling bumps

Biological Perspective

The study of the brain that focuses on the connection between our bodies and our mind

Neuron

a nerve cell; the basic building block of the nervous system

Dendrites

part of the neuron that receives messages from other neurons

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

Refractory Period

neuron's resting pause; pumps sodium ions outside so it is ready to fire again

Myelin Sheath

a layer of fatty tissue that speeds neutral impulses

Action Potential

a brief electrical charge that travels down the axon when triggered by neighbors

Threshold

the level of simulation required to trigger a neural response

Synapses

meeting point between 2 neurons

Synaptic Gap

separation between axon and the receiving neuron

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 an impulse

Acetycholine

a neurotransmitter associated with learning and memory and is a messenger at every motor neuron

Dopamine

a neurotransmitter primarily involves in movement, attention, and pleasure

Serotonin

a neurotransmitter that affects mood, hunger, sleep, and arousal

GABA

a major inhibitory neuron

Reuptake

a neurotransmitter's reabsorption by the sending neuron

Endorphins

an opiate that is produced by the brain in response to pain and vigorous exercise

Nervous system

the body's speedy, electrochemical communication network

Central Nervous System

includes the brain and spinal cord

Peripheral Nervous System

the sensory and motor neurons that connect the central nervous system to the rest of the body

Nerves

bundles of axons that link the central nervous system with the body's sensory, muscles, and glands

Sensory (afferent) neurons

carry incoming information to the central nervous system for processing

Motor (efferent) neurons

carry outgoing information from the brain to muscles

Interneurons

neurons with in the brain and the spinal cord that communicate and intervene between the sensory inputs and the motor outputs

Somatic nervous system

voluntary control of your muscle

Autonomic nervous system

controls the glands and muscles of inner organs and usually operates on its own

Sympathetic nervous system

the division of the autonomic nervous system that arouses and expends energy in stressful situations

Parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

Reflexes

a simple, automatic response to a sensory stimulus

Endocrine system

the body's "slow" chemical communication system, a set of glands that secrete hormones

Hormones

chemical messengers that are produced by the endocrine glands, travel through the blood, and affect other tissues

Adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress

Pituitary gland

a pea-sized structure controlled by the hypothalamus, releases growth hormones, oxytocin, and more

Lesion

tissue destruction used by scientists to observe its effect

Soma

the cell body

Axon terminal

the endpoint of a neuron where neurotransmitters are released

excitatory neurotransmitters

chemicals released from the terminal buttons of a neuron that excite the next neuron into firing

inhibitory neurotransmitters

inhibit the next cell from firing

Nodes of Ranvier

small spaces between the myelin sheath that allows neurotransmitters to jump

Synaptic vesicles

a small cavity or sac in the axon terminal that contains neurotransmitters

Post-synaptic membrane

the leading edge of the receiving dendrite

Agonist

drugs that mimic neurotransmitters

Antagonists

drugs that block the function of a neurotransmitter

all or nothing

principle that either a neuron is sufficiently stimulated and an action potential occurs or a neuron isn't sufficiently stimulated and an action potential doesn't occur

Oxytocin

a hormone released by the pituitary gland that causes love and bonding

Pineal gland

secretes melatonin

Electroencephalogram (EEG)

record of the electrical activity of the brain at different stages of consciousness (function)

Positron Emission Tomography (PET)

a method of brain imaging that inserts a harmless radioactive substance into the brain and track where the brains are active during each task (function)

CAT scan

x-ray cameras that rotate around the brain to create a 3D picture (structure)

MRI (magnetic resonance imaging)

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue (structure)

fMRI (functional MRI)

a MRI technique used to reveal blood flow, therefore reveals brain activity (function)

Brainstem

the oldest, central, innermost part of the brain, beginning where the spinal cord swells. Includes the pons, midbrain, and medulla

Medulla

the slight swelling of the spinal cord and is the base of the brainstem that controls rhythmic activities (ex. heartbeat)

Thalamus

the brain's switchboard: directs messages to the sensory receiving regions in the cortex and transmits replies to the cerebellum and medulla

Reticular Formation

a nerve network that extends through the pons, midbrain, and medulla that travels through the brain stem and controls arousal

Cerebellum

the "little brain" at the rear end of the brain stem which enables nonverbal learning and memory (ex. movement)

Limbic system

a neural structure located below the cerebral hemispheres associated with emotions and drives (amygdala, hippocampus, hypothalamus)

Amygdala

two lima bean-sized neural clusters in the limbic system; linked to emotion

Hypothalamus

a neural structure lying below the thalamus and is in the limbic system; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion; associated with rewards/punishments system

Hippocampus

a neural center located in the limbic system; helps process explicit memories for storage

Cerebral cortex

a thin layer of interconnected neurons that cover the cerebral hemispheres, which is the body's ultimate information processing center

Frontal Lobe

portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements in making plans and judgements

Prefrontal cortex

part of frontal lobe responsible for thinking, planning, and judgement

Parietal Lobe

portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position

Occipital Lobe

portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields

Glial Cell

cells in the nervous system that support, nourish, and protect neurons

Temporal Lobes

portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear

Motor Cortex

an area of the rear frontal lobe that controls precise, voluntary movements

Sensory Cortex

area at the front of the parietal lobes that registers and processes body touch and movement sensations

Association areas

areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking

Plasticity

the ability to change, especially during childhood, by reorganizing after damage or build new ways based on experienced

Neurogenesis

the formation of new neurons

Corpus Callosum

the large band of neural fibers that connects two hemispheres and is responsible for relaying messages between them

Split 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

Contralateral control

each hemisphere of the brain controls the opposite side of the body

hemispheric lateralization

each brain hemisphere specializes in performing different functions

Broca's area

an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech (BROken speech)

Wernicke's area

a brain area involved in language comprehension and expression; usually in the left temporal lobe (WEird speech)

Dual Processing

the principle that information is often simultaneously processed on separate conscious and unconscious tracks

Blindsight

a condition in which a person can respond to a visual stimulus without consciously experiencing it

Selective attention

the focusing of conscious awareness on a particular stimulus

inattentional blindness

failing to see visible objects when our attention is directed elsewhere

change blindness

failing to notice changes in the environment

waking consciousness

state in which thoughts, feelings, and sensations are clear, organized, and the person feels alert

consciousness

awareness of ourselves and the environment

Subconscious

not fully aware; occurring below your level of thinking and awareness; stores memories you have no use for right now

Unconscious

part of the mind that processes information of which we are unaware

Circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

Sleep stage 1

theta waves; brief transition stage when first falling asleep

Sleep stage 2

sleep spindles; base line of sleep

Sleep stage 3

delta waves; deep sleep

Sleep stage 4

delta waves; deepest sleep

REM Sleep

a stage of sleep characterized by rapid eye movements and a high level of brain activity

REM rebound

increased amounts of REM sleep after being deprived of REM sleep on earlier nights

Beta waves

Brainwaves detected by an EEG that represent a state of fully alert wakefulness

Alpha waves

brain waves that indicate a state of relaxation or light sleep

Theta waves

brain waves indicating the early stages of sleep

Delta waves

the large, slow brain waves associated with deep sleep

Sleep spindles

bursts of rapid, rhythmic brain-wave activity