ap psych unit 2

DNA

main constituent of chromosomes. found in all living organisms, transmits hereditary characteristics from parent to children

chromosome

threadlike, linear strand of DNA encoded with genes. unique to each human

genes

segments of DNA that occupy a specific place on a specific chromosome and carry code for hereditary transmission

heritability

a statistical formula that provides a percentage of variation in a population attributable to genetic factors rather than environment. not applicable to the individual

glial cells

hold and support neurons, supply nutrients and oxygen, perform cleanup tasks, isolate neurons from each other. roughly 90% of the matter in the brain

neuron

cells responsible for receiving sensory input from the external world, for sending motor commands to muscles, for transforming and relaying electrical signals

dendrites

branching fibers of neurons that receive neural impulses from other neurons and convey impulses toward the cell body. each neuron might have hundreds or thousands

cell body (soma)

part of a neuron that contains the cell nucleus and other structures that help the neuron carry out its functions. info from dendrites flows here, from here to the axon

axon

long tube-like structure that conveys impulses away from a neuron's cell body toward other neurons or to muscles or glands. carries info from cell body to terminal buttons

action potential

a neural impulse or brief electrical charge that carries info along the axon of a neuron, movement is generated when positively charged ions move in and out through channels in axon's membrane

myelin sheath

layer of fatty insulation wrapped around the axon of some neurons that increases the rate at which neural impulses travel along the axon. insulates and speeds neural impulses

neurotransmitters

chemical messengers released by neurons that travel across the synapse and allow neurons to communicate with one another. dane's egg

dopamine

influences movement, attention, memory, learning, emotion, reward. problems --\> schizophrenia, Parkinson's. affected by --\> cocaine, amphetamines, Ritalin, alcohol

acetylcholine

influences muscle action, REM sleep, emotion, some learning and memory. problems --\> muscular disorders, Alzheimer's. affected by --\> nicotine, botulism toxin, atropine

norepinephrine

influences HR, arousal, stress, vigilance, appetite. problems --\> low-depression, high-maniac. affected by --\> antidepressants, beta blockers

serotonin

influences sleep and dreaming, mood, pain, aggression, appetite. problems --\> anxiety, depression, OCD. affected by --\> prozac, hallucinogenics (LSD)

endorphins

pleasurable sensations, control of pain, memory, learning, blood pressure, appetite. low levels can result from opiate addiction

glutamine

primary excitatory neurotransmitter in CNS. learning and memory. Brain damage,age after stroke, factor in migraines, anxiety, depression. affected by --\> PCP

GABA

most prevalent inhibitory neurotransmitter in CNS, calming effect. problems --\> anxiety, epilepsy. affected by --\> barbiturates, tranquilizers, alcohol

hormones

chemical messengers released from endocrine system into bloodstream (like a global email)

endocrine system

network of glands that manufacture and secrete hormones into bloodstream. Helps regulate long-term bodily processes (growth) and maintains ongoing bodily processes (digestion). Controls body's response to emergencies

stem cells

immature (uncommitted) cells that have the potential to develop into almost any type of cell. used to replace lost brain cells (neurogenesis)

neurogenesis

creation of new brain cells. stem cells used to replace lost brain cells (neurons)

central nervous system (CNS)

brain and spinal cord, allows for the processing of information and adaptation to the environment. very fragile. role in controlling awareness, movement, sensations, thoughts, speech

peripheral nervous system (PNS)

composed of nerves and neurons connecting CNS to the rest of the body. divided into the SNS and ANS. carries action potential between the CNS and periphery of body. links CNS to sense receptors (eyes, skin, ears), muscles, and glands

autonomic nervous system (ANS)

controls involuntary tasks (heart rate, digestion, breathing). connects sensory receptors to CNS and CNS to smooth muscle, cardiac muscle, and glands. composed of sympathetic and parasympathetic nervous systems

sympathetic nervous system

active during stress. responsible for arousing body and mobilizing its energy (fight or flight)

parasympathetic nervous system

responsible for calming down and conserving energy

somatic nervous system (SNS)

connects CNS to skeletal muscles, carries messages from CNS to control skeletal muscles, carries sensory information to CNS. composed of sensory and motor nervous systems

sensory nervous system

neurons send incoming information from sense receptors to CNS

motor nervous system

neurons send outgoing info from CNS to muscles and glands

hindbrain

lower region, composed of medulla, pons, and cerebellum. controls automatic behaviors and survival responses.

medulla

responsible for vital, automatic functions (heart rate, respiration). essentially an extension of the spinal cord with many neural fibers carrying information to and from the brain

pons

involved in respiration, movement, sleeping, waking, and dreaming. contains axons that cross from one side of the brain to the other (in Latin, means "bridge").

cerebellum

responsible for coordinating fine muscle movement, balance, some perception and cognition. Latin "little brain." evolutionary very old. tells us what to expect from certain movements

midbrain

helps orient eye and body movement to visual and auditory stimuli. works with pons \-- sleep, arousal level.

reticular formation

runs through hindbrain, midbrain, and brainstem. diffuse, finger-shaped network of neurons, helps to screen incoming sensory information, alert higher brain centers to important events. without it, we would probably not be alert, or even conscious

forebrain

contains higher-level structures and functions. deals with sensory input, drives, endocrine system, limbic system, cerebral cortex

thalamus

integrates input from senses (not smell), may also function in learning and memory. brain's switchboard. receives information from sensory systems and directs it to appropriate cortical areas

hypothalamus

small brain structure, helps govern drives (hunger, aggression). controls internal body temp via regulation of the endocrine system. directly influences aspects of behavior like eating and drinking patterns. lateral--hunger, medioventral\-- satiety.

pituitary gland

master endocrine gland. releases hormones that activate other endocrine glands. hypothalamus controls via direct neural connection and release of own hormones into pituitary bloodsteam

limbic system

interconnected group of forebrain structures generally responsible for emotion, drives, and memory. hippocampus, amygdala, etc.

hippocampus

sea-horse shaped part of limbic system involved in forming and retrieving memories

amygdala

(limbic system) controls emotions like aggression and fear, formation of emotional memory. tied with frontal cortex (what kind of decision is being made)

cerebral cortex

gray and wrinkled surface layer of the cerebral hemispheres. approx. 30 billion neurons, 270 billion glia. numerous wrinkles (convolutions) increase surface area. higher brain functioning

right versus left hemispheres

control opposite sides of the body.

left

language functions (speak, write, read, understand

right

some language (nonverbal), art, music, spatiomanipulative skills, recognize faces

split brain research (Sperry/Gazzaniga)

studied people after corpus callosum severed. found two different brains exist, each with complex abilities. specialized skills in each brain (left better at speaking, writing, math, reading, language while right better at recognizing faces, spatial relationships, symbolic reasoning, and artistic activities.)

corpus callosum

bundle of neural fibers that connect the two hemispheres

frontal lobes

govern motor control, speech production, and higher functioning such as thinking, personality, emotion, and memory. receive and coordinate messages from all other lobes. attention, motivation, decision making

Broca's area

left frontal lobe near bottom of motor control area. crucial role in speech production (not language comprehension). damage --\> \____'s aphasia (can't speak but can understand)

motor cortex

back of frontal lobes, sends messages to various muscles that instigate voluntary movement

parietal lobes

bodily sensations are received and interpreted. process info about touch, pressure, vibration, and pain.

somatosensory cortex

(parietal lobe). band of tissue that processes tactile info about different body parts.

temporal lobes

involved in audition, language comprehension, memory, some emotional control

auditory cortex

(temporal lobe). processes sound. responsible for receiving incoming sensory info and sending it to parietal lobes where it is combined with other info

Wernicke's area

part of left temporal lobe, aids in language comprehension. works with Broca's area. damage --\> \____'s aphasia (don't understand what is heard or read, but can speak (usually unintelligibly)

occipital lobes

primarily responsible for vision and visual perception. damage can cause blindness even while eyes and their neural connection to the brain is intact

biological techniques

help study brain activity

electroencephalogram (EEG)

records waves of electricity, measured by electrodes on scalp reveals active areas of brain, traces abnormal waves from malfunction (epilepsy/tumor)

computed tomography (CT)

series of xray photos from different angles. combined via computer to produce 3D image that reveals effects of strokes, injuries, tumors, and other brain disorders. aka CAT scan

positron emission tomography (PET)

depicts brain activity by showing each brain area's consumption of glucose. produces computer-constructed picture of brain, detect abnormalities, active areas

magnetic resonance imaging (MRI)

uses magnetic fields and radio waves to produce computer generated image of soft tissue. identifies abnormalities, maps brain structure and function

functional MRI (fMRI)

detects blood flow (indicator of activity) by picking up magnetic signals from blood. measures brain activity by comparing successive scans

bottom-up processing

perceptual analysis, begins with raw sensory data sent to brain for higher-level analysis

top-down processing

perceptual analysis that starts with higher level cognitive processes (expectations, knowledge) then works down (whole to parts)

transduction

process whereby sensory receptors convert stimuli into neural impulses to be sent to brain

coding

process in which neural impulses travel by different routes to different parts of the brain, allowing detection of various physical stimuli

difference threshold (Weber's First Law)

smallest discernible difference. minimum difference between stimuli consciously perceived 50% of the time

absolute threshold (Fechner)

the minimum amount of stimulation necessary to consciously detect a stimulus 50% of the time

sensory adaptation

process by which receptor cells become less sensitive due to constant stimulation. receptors feel "tired" and fire less frequently.

gate-control theory of pain

suggests that the experience of pain depends partly on whether the neural message gets past a "gatekeeper" in the spinal cord.

trichromatic theory of color

color perception results from 3 types of cones in retina, each sensitive to red/green/blue. other colors result from a mix

opponent-process theory of color

color perception based on 3 systems of color opposites (red/green, blue/yellow, black/white). explains afterimages

sight

uses light waves that bounce off objects. given priority (w/ hearing) by brain

rods

photoreceptors concentrated in periphery of retina, most active in dim illumination. black, white, gray, and peripheral vision

cones

visual receptor cells concentrated near center of retina. color vision, fine, detail, light

blind spot

point at which optic nerve leaves the eye, contains no receptor cells for vision, creates tiny hole

retina

light sensitive inner surface of the back of the eye, contains receptor cells for vision (rods and cones)

lens

focuses image on retina

cornea

transparent outer layer of the eye (covers iris, pupil)

hearing

audition. given priority (with sight) by brain. sound waves produced by air molecules moving in a particular wave pattern. ears detect small pressure changes, brain interprets, produces a neural message

audition

sense of hearing

ear canal

funnels sound to inner ear/ear drum

tympanic membrane (eardrum)

thin membrane at end of ear canal, vibrates with sound waves, striking the mid-ear's ossicles

ossicles (hammer, anvil, stirrup)

three tiny bones of middle ear, vibrate with sound waves, send to cochlea's oval window

cochlea

fluid filled, coiled tube in the inner ear that contains the receptors for hearing

place theory

pitch perception is linked to the particular spot on the cochlea's basilar membrane that is most stimulated. pitch is coded by place at which activation occurs

(high)

frequency theory

pitch perception is occurs when a tone produces a rate of vibration in the basilar membrane equal to its frequency. pitch coded by the frequency of neural response

(low)

amplitude

determines how sound is detected as loud (high peaks) or soft (shallow peaks)

frequency

high frequency-high pitched sounds. low frequency-low pitched sounds

conduction hearing loss

results from damage to mechanical system that conducts sound waves to the cochlea. aka conduction deafness

sensorineural heaing loss

results from damage to cochlea's receptor (hair) hearing cells or to the auditory nerves. aka nerve deafness

tough

essential for development, skin sensations

skin sensations

pressure, warmth, cold, pain

pain

associated with actual or potential tissue damage, brain remembers at peak and at end. perceive more when others do

nociceptors

pain receptors. detect temperature, pressure, or chemicals