AP Psych. Unit 2 Biological Bases of Behavior (Part 2: sleep, consciousness, and sensation)

sensation

process by which our sensory receptors and nervous system receive and interpret stimulus energies from our environment

sensory receptors

sensory nerve endings that respond to stimuli

perception

process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

bottom-up processing

analysis that begins with the sensory receptors and works up to the higher levels of mental processing 

top-down processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations

transduction

the process of converting one form of energy into another form of energy that your brain can use (recieve, transform, deliver)

psychophysics

studies the relationship between physical energy we can detect and its effects on our psychological experiences

Gustav Fechner

early German psychologist credited with founding psychophysics

absolute threshold

the minimum stimulation needed to detect a particular stimulus 50% of the time

signal detection theory

predicts how and when we detect a faint stimulus (signal) amid background stimulation (noise)

subliminal

signals you can’t detect 50% of the time; below your absolute threshold 

priming

unconsciously activating certain associations, predisposing our perceptions, memory, or response

difference threshold (just-noticeable difference)

the minimum difference between two stimuli required for detection 50% of the time

Ernst Weber

identified just-noticeable-difference (JND) that eventually becomes Weber’s law

Weber’s law

principle that, to be perceived as different, two stimuli must differ by a constant minimum threshold as just noticeable difference 

sensory adaptation

decreased receptor firing as a consequence of constant stimulation

habituation

decreased mental response to a stimulus after frequent repeated exposure

wavelength

distance from one wave peak to the next

hue

the color we experience

intensity

the amount of energy in light waves (determined by waves height/amplitude)

cornea

the transparent, dome-shaped front layer of the eye that covers the iris and pupil

pupil

a small adjustable opening

iris

the colored muscle in your eye that dilates or constricts depending on light intensity

lens

focuses the incoming light into an image on the retina

retina

a multilayered tissue on the eye’s sensitive inner surface

accommodation

lens changes shape to focus on near or far objects

photoreceptor cells

rods and cones

rods

detect black, white & gray; necessary for peripheral and twilight vision

cones

detect fine details and color sensation; cluster in and around the fovea (color, clarity, center)

optic nerve

the nerve that carries neural impluses to your brain

blind spot

the spot where your optic nerve meets your retina and you have no receptor cells

fovea

the central focal point in the retina, around which the eye’s cones cluster

young-hemholtz trichromatic (three color)

theory that the retina contains three different color receptors- one most sensitive to red, one to green, and one to blue; when stimulated in combination can produce the perception of any color

dichromatism

people that can’t see either red/green shades or blue/yellow shades

monochromatism

people that can only see shades of gray

opponent-process theory

the theory that opposing retinal processes(red-green, yellow-blue, white-black) enable color vision

David Hubel

sensation and perception - discovered feature detectors

Torsten Wiesel

David Hubels partner; discovered feature detectors in the visual system

feature detectors

specialized neurons in the occipital lobe that respond to specific features of stimuli such as shape, angle, or movement

parallel processing

the brain’s ability to simultaneously process multiple pieces of information or stimuli

audition

hearing; the sense of sound perception

loudness

a sound’s intensity determined by the amplitude of sound waves

frequency

determines the pitch

pitch

a tone’s experienced highness or lowness; depends on frequency

middle ear

three tiny bones called ossicles (hammer, anvil, stirrup)

cochlea

a snail shaped tube in the inner ear

inner ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

sensorineural deafness (nerve deafness)

damage to cochlea’s hair cell receptors

conduction deafness

damage to mechanical system that conducts sound waves to the cochlea

cochlear implant

converts sounds to electrical signals and stimulates the auditory nerve

place theory

hair cells in the cochlea respond to different frequencies of sound based on where they’re located in the cochlea

frequency theory

the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, enabling us to sense its pitch

sound localization

two ears (as opposed to one) help us locate sources of sound

gate-control theory

spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on the brain

gustation

our sense of taste

umami

a savory, meaty taste (Ex. tomatoes, seaweed, cheeses, ham)

oleogustus

the unique taste of fat (prominent in foods that are rancid or stale)

supertasters

have taste buds that are packed closer together, causing them to experience flavors with more intensity

nontasters

having the fewest taste buds (farthest apart taste buds)

medium taster

average number of taste buds

olfaction

sense of smell

kinesthetic sense

gives feedback on overall orientation of specific body parts; receptors in muscles and joints send information to our brains about our limbs (how we know where our limbs are)

vestibular sense

tells us how our body is oriented in space, 3 semicircular canals in inner ear give the brain feedback on orientation (balance)

sensory interaction

the principle that one sense may influence another as when the smell of food influences taste (Ex. visual cues help us to know what we are hearing)

embodies cognition

the influences of bodily sensations, gestures, and other states on cognitive preferences and judgements (Ex. when someone is holding a warm drink rather than cold, people are more likely to rate someone more warmly)

consciousness

our awareness of ourselves and our environment

cognitive neuroscience

the interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory,and language)

dual processing

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

parallel processing

processing multiple aspects of a stimulus or problem simultaneously (unconsciously) 

sleep

periodic loss of consciousness in order to physically and psychologically repair and restore the brain and body

wakefulness (wave types)

awake and alert = beta waves

awake, relaxed, ready to fall asleep = alpha waves

circadian rhythm

the biological block, regular bodily rhythms that occur on a 24-hour cycle

circadian rhythm hormone

melatonin

what tool is used to measure brain waves and sleep

EEG

type of brain wave for NREM-1

alpha

type of brain wave for NREM-2

theta

type of brainwave for NREM-3

delta 

NREM stage 1

lightest level of sleep, 10 mins long, pulse slows, muscles relax, may hallucinate (hyponogogic sensation)

hyponogogic sensations

vivid sensations like muscle twitches or the feeling of falling during the transition between sleep and wakefulness 

NREM stage 2

20 mins long, transition to theta waves, sleep spindles

NREM stage 3

deepest level of sleep, 30 mins long, sleepwalking/sleeptalking/bed-wetting, important for well being, produce growth hormones 

REM sleep

rapid eye movement sleep, irregular pulse/heart rate, may twitch, large muscles are paralyzed, vivid dreams, paradoxical sleep

REM rebound

the tendency for REM sleep to increase following REM sleep deprivation

why is REM sleep considered paradoxical sleep?

because you have the same brain waves as when you are awake (beta), eyes are also moving

jet lag and shift work

jet lag: fatigue and disorientation after traveling across multiple time zones

shift work: work schedule that involves hours outside the typical 9-5 (early morning, night shifts, etc)

memory consolidation theory

sleep plays a crucial role in the process of converting short term memories to long term memories by strengthening neural connections 

restoration theory

sleep is necessary for the body and mind to restore and recover from daily activities

effects of sleep deprivation

memory fog, poor focus, slow reaction time, weakened immune system, anxiety, mood swings, depression risk 

insomnia

reoccurring problems of falling asleep or staying asleep

causes: stress/anxiety, depression, drug/alcohol abuse, irregular sleep schedule

narcolepsy

uncontrollable sleep attacks, sufferer may lapse directly into REM at inopportune times

causes: stress/anxiety, depression, drug/alcohol abuse, irregular sleep schedule

sleep apnea

temporary cessations of breathing during sleep and repeated awakening (sleep without breath)

causes: enlarged tonsils, obesity, recurring infection 

somnambulism (sleep walking/talking)

sleep walking or talking during NREM-3 sleep, often not recalled, affects mostly children

causes: heredity, stress/anxiety, sleep deprivation

REM sleep behavior disorder

muscle paralysis fails, brain is sleeping yet person may talk or yell, make large/aggressive movements (punching, kicking, etc)

activation synthesis theory - J. Allan Hobson

proposes that dreams result from the brain’s attempt to make sense of random neural activity (by making into a coherent narrative) 

consolidation theory

proposes that sleep plays a crucial role in strengthening memories by moving them from short term to long term storage