Psych Midterm 2

sensation

sensation

sense detect visual, auditory, and other sensory stimuli to the brain

perception

sensory information is actively organized, interpreted by the brain

exteroceptors

goes from sensation to perception through exteroceptors into brain; external

interceptors

send internal messages to the brain (hunger, thirst etc.); internal

proprioceptors

receives stimuli from within the body in relation to position and movement

absolute threshold

difference between not being able to perceive stimulus and being just barely able to perceive it

difference threshold

measure of smallest increase/decrease in physical stimulus required to produce JND (smallest change in sensation)

signal detection theory

detecting sensory stimulus involves noticing stimulus against background "noise" and deciding whether stimulus is actually present

sensory receptors

detect, respond to one type of stimuli

transduction

sensory receptors change sensory stimulation

sensory adaptation

become less sensitive to unchanging sensory stimulus over time

cornea

transparent, protective covering front of eye, bends light rays inwards, through pupil

pupil

small dark opening in centre of iris

iris

coloured part of eye, muscles dilate and contract pupil through reflex

lens

suspended behind iris and pupil, composed of many thin layers, flattens when focusing on distant objects, bulges while focusing on close objects

nearsightedness

distance through eyeball too short or too long; see nearby objects clearly, distant objects blurry

farsightedness

focal image larger than eye can handle; see distant objects clearly, close objects blurry

rods

light sensitive receptors in retina, respond to black and white

cones

receptor cells in retina, see colour and fine detail, dont function well in dim light

fovea

small area of retina, clearest point of vision, receptors change light rays into neural impulses

optic chiasm

optic nerves from both eyes come together and nerve fibres cross to opposite sides of brain, helps depth perception

feature detectors

certain neurons in brain, respond only to specific visual patterns (lines or angles)

pinna

visible curved flap of cartilage and skin on the ear

auditory canal

leads to eardrum, lined with hairs

eardrum

thin flexible membrane, moves in response to sound waves

ossicles

inside chambers of middle ear, amplify sound

cochlea

produce electrical impulse transmitted to brain

olfaction

sensation of smell; a chemical sense

olfactory epithelium

patch of tissue at top of each nasal cavity, contains 10 million smell receptor cells

olfactory bulbs

2 matchstick sized structures above each nasal cavity, smell first registers in brain, messages relayed to different parts of brain

pheromones

chemicals excreted by humans and animals, elicits certain behaviour patterns

gustation

sense of taste

flavour

combined sensory experience of taste, smell, touch

gate control theory

pain signals can be transmitted or inhibited by "gate" in spinal cord

endorphins

block pain and produce feelings of well being

kinesthetic sense

feedback about movement and position of various body parts

vestibular sense

detects movement, provides information about body's orientation in space

gestalt principles of grouping

similarity, proximity, continuity, closure

convergence

eyes turn inward while focusing nearby objects; closer object, greater convergence

binocular disparity

difference between 2 retinal images, cues for depth and balance

interposition

perceive partially blocked object as further away

linear perspective

parallel lines appear to converge into distance

relative size

larger objects perceived as closer to viewer, smaller objects as farther away

texture gradient

nearby object to have sharply defined textures, similar objects appear smoother, appear fuzzier as fade into distance

atmospheric perspective

distant objects have bluish tint, distant objects appear more blurred than close objects

motion parallax

objects appear to be moving in different directions and different speeds, close objects appear to move faster than distant ones

real vs apparent motion

real - movements of objects through space apparent - psychological

ambiguous figures

2 different objects, figures seen alternately

impossible figures

parts appear to be 2 different places at same time

illusions

false perceptions of actual stimulus in environment

bottom up processing

individual components of stimulus detected by sensory receptors, information transmitted to areas of brain then combined, assembled into whole pattern person perceives

top down processing

past experience/knowledge of context plays role informing perceptions

consciousness

a continuous stream of thoughts, feelings, sensations, perceptions

circadian rhythms

controlled by the brain, within each 24hr period high to low points of bodily functions (ex. blood pressure, heart rate, appetite etc)

ultradian rhythms

more than once a day, (hunger patterns, eye blinks, heartbeats)

infradian rhythms

cycle exceeds 24hr period (female menstrual cycle)

suprachiasmatic nucleus

small structure in hypothalamus, acts as biological clock, responds to amount of life

NREM sleep

quiet sleep, heart rate and respiration slow, little body movement, blood pressure and brain activity at lowest points

REM sleep

active sleep, paralysis of large muscles, fast irregular heart and respiration rate, increased brainwave activity

microsleeps

2-3 second sleeps, due to deep sleep deprivation

REM rebound

increased amount of REM sleep, due to REM deprivation from sleep loss, alcohol, illness etc.

REM dreams

vivid dreams we remember, continuous during each REM period

NREM dreams

mental activity during NREM sleep, more thought-like in quality

short vs long sleepers

short - less than 6 hours, 20% of population long - more than 9 hours, 10% of population

parasomnia

sleep disturbances, behaviours, psychological states normally occur in waking state occur during sleep state

sleepwalking

eyes open, blank stare, shuffle, poor coordination, speech is unintelligible

sleep terror

often begins with piercing scream and panic, lasts 5-15 mins, often no memory of episode

nightmares

frightening dreams during REM sleep

sleeptalking

occurs during any sleep stage, more frequent in children

narcolepsy

incurable sleep disorder, excessive daytime sleepiness, uncontrollable attacks of REM sleep

sleep apnea

breathing stops during sleep, sleep is light, restless or poor

meditation

focus attention on object, word breathing or body movement to block out all distractions, altered state of consciousness

hypnosis

trance-like state of concentrated and focused attention; distortions in perceptions memories, thinking; aware of what is going on

psychoactive drugs

alter normal mental functioning, mood, perception, thought; controlled substances used medically; can trigger dopamine in brain's limbic system, involved in reward and motivation

factors that influence addictive potential of drug

1. how quickly effects are felt

2. how pleasurable effects are

3. how long pleasurable effects last

4. how much discomfort when drug discontinued

stimulants

speed up CNS, suppress appetite, feel more awake, alert, energetic

caffeine

mental alertness increases, stay awake, lifts mood, found in coffee, tea, cola, chocolate

amphetamines

increase arousal, relieves fatigue, suppresses appetite, gives energy

cocaine

gives euphoria then crash

hallucinogens

alter perceptions and mood, cause hallucinations

LSD

"trips" of 10-12 hours, vivid hallucinations and distortions, flashbacks

ecstasy

designer drug, joyous state, can impair cognitive functions

marijuana

relaxation and giddiness, perceptual distortions and hallucinations, amotivational syndrome

depressants

decrease activity in CNS, slow bodily functions, reduce sensitivity to outside stimulation (narcotics)

alcohol

relaxes then depresses CNS

narcotics

relieves pain, calming effects

dopamine

affects nucleus accumbens in brain's limbic system, role in reinforcement and reward

endorphins

opiates mimic effects of brain's endorphins, pain relieving properties

GABA

act on GABA receptors, slows CNS, calming sedating effect

learning

permanent change in behaviour, knowledge, capability, or attitude; acquired through experience

classical conditioning

response previously made to specific stimulus, made to another; association formed between 2 stimuli; involuntary form of learning

stimulus

any event or object in environment to which organism responds (ex. light, sound, touch)

reflexes

unlearned, automatic responses to environmental stimuli (ex. swallowing, coughing, blinking)

unconditioned reflex

involuntary response to stimuli (ex. eye blink to puff of air, salivation response to food)

conditioned reflex

learned involuntary responses

unconditioned response (UR)

automatic, unlearned response to US

unconditioned stimulus (US)

stimulus elicits UR

conditioned response (CR)

learned response to CS

conditioned stimulus (CS)

previously neutral stimulus; after repeated pairings with US, produces CR

extinction

weakening of learned response, eventual disappearance of learned response