psychology unit 2

sensation

sensation

the activation of sense organs by a source of physical energy

stimulus

energy that produces a response in a sense organ

perception

the sorting out, interpretation, analyis, and integration of stimuli by the sense organs and brain

psychophysics

the study of the relationship between the physical aspects of a stimulus and peoples psychological experience of the stimulus

absolutle threshold

the lowest intensity of a stimulus that an organism can detect

difference threshold (just noticeable difference)

the smallest level of added or reduced stimulation required to sense that a change in the stimulation has occurred

Weber’s law

states that a just noticeable difference is a constant proportion to the intensity of an intial stimulus

adaptation

an adjustment in sensory capacity after prolonged exposure to unchanging stimuli

Gestalt Laws of Organization

series of principles that describe how we organize bits and pieces of information into meaningful wholes

top-down processing

perception that is guided by higher level knowledge, experience, expectations, and motivations

bottom-up processing

perception that consists of the progression of recognizing and processing information from the individual components of a stimuli and moving to the perception of a whole

depth perception

the ability to view the world in 3 dimensions and to percieve distance

binocular disparity

the difference in images seen by the left and right eye

perceptual constancy

our understanding that physical objects are constant and do not vary, even though sensory input about them might vary

visual illusions

physical stimuli that consistently produce errors in perception

subliminal perception

the perception of messages about which we have no awareness

consciousness

the awareness of sensations, thoughts, and feelings we are experiencing at a given moment, an understanding of environment around us and our private internal world

unconscious wish fulfillment theory

sigmund freuds theory that dreams represent unconscious wishes that dreamers desire to see fulfilled

manifest content

part of the dream that we remember, the story line

latent content

underlying wishes that the dream represents

dreams for survival theory

theory suggesting that dreams permit information that is critical for our daily survival to be reconsidered and reprocessed during sleep

activation synthesis theory

hobsons theory that the brain produces random electrical energy during REM sleep that stimulates memories stored in the brain

circadian rythms

biological processes that occurr regularly on 24 hr cycle

daydreams

fantasies that people construct while awake

suprachiasmatic nucleus

controls circadian rhythms

synthethesia

condition in which two sneses are sensed at the same time

transduction

transformation of stimulus energy to electrochemical energy of neural impulses

signal detection theory

theory predicting how and when we detect presence of faint stimulus amid background stimulation

selective attention

we center our attention on certain elements of our environment while other things blend into the background

divded attention

when metnal focus is on multiple tasks or ideas, multitasking

inattentiohnal blindness

focus is directed at one stimulus, blinding us to other stimuli

change blindness

tendency to miss changes in immediate visual environment

taste (gustation)

tastes we perceive are a two phse chemical reaction involving both our mouth and throat and nose

smell (olfaction)

chemical molecules breathed in through nose, smell receptors lie in top of nasal passage, send impulses along olfactory nerve to olfactory bulb

somesthetic senses

senses of skin allow us to feel light touch, pressure, pain, cold, and warmth

pain

body’s warning signal that something is not right

gate control theory

gate exists in spinal cord that switches pain on and off

kinesthesis

system for sensing the position and movement of individual body parts

gestalt psychologists

emphasize brains tendency to integrate pieces of info into meaningful wholes

figure-ground pattern

tendency of visual system to simpligy a scene into main object we’re looking at, and put everything else in the background

grouping

brains have tendency to organize stimuli into groups in order to process the complexity of the world

binocular cues

require use of both eyes to perceive depth and distance

convergence

our eyes move together to focus on an object that is close and that they would move farther apart for a more distant object

monocular cues

cues that can be used for depth perception that involve only 1 eye, forms 3D from 2D

linear perspective

depth cue, makes parallel lines appear to converge at a vanishing point on horizon

interposition

when one object overlaps anothers, partially obscured object is perceived as being farther away

relative size

if two objects are the same size, the farther away object will appear smaller

relative height

we perceive objects higher in visual field as being further away, closer ones should be lower

relative clarity

hazy obects are farther away than sharper/clear objects

texture gradient

mthod of determining depth by noting distant objects are smoother in texture

relative motion

when you are in motion, closer objects seem to zoom by faster than objects in the distance

perceptual set

predisposition to perceive things in a certain way

perceptual constancy

tendency to perceive an object you are familiar with as having constant shape, size, and brightness despite changes occurring

lightness constancy

we perceive an object to have constant lightness even while illumination varies

shape constancy

constancy we perceive objects as having constant size even while distance varies or angles

parapsychology

study of alleged psychic phenomena

non- REM stage 1

theta waves increase, alpha waves fade away, sensation of falling

non-REM stage 2

body temp drops, sleep spindles, sleeptalking

non-REM stage 3

deepe sleep, delta waves, most restorative, hard to awaken

REM sleep

pardoxical sleep, rapid eye movements, muscles paralyzed, brain waves as if we are awake

REM paralysis

presence of features of REM during transition into/ out of sleep

microsleep

fleeting, uncontrallable brief episode of sleep, ranges from fraction of a second to 10 seconds

learning

relativelt permanent changed in behavior brought about by experience

classical conditioning

a type of learning in which a neutral stimulus comes to bring about a response after it is paired with a stimulus that naturally brings about that response

neutral stimulus

a stimulus that before conditioning does not naturally bribng about the response of interest

unconditioned stimulus

stimulus that naturally brings about a particular response without having been learned

unconditioned response

response that is natural and needs no training

conditioned stimulus

once neutral stimulus that has been paired with an unconditioned stimulus to bring about a response formerly caused only by the unconditioned stimulus

conditioned response

response that after conditioning, follows a previously neutral stimulus

phobias

intense, irrational fears

extinction

occurs when a previously conditioned response decreases in frequency and eventually disapears

spontaneous recovery

the reemergence of an extinguished conditioned response after a period of rest and with no further conditioning

stimulus generalization

process in which after a stimulus has been conditioned, stimuli that are similar to original stimulus produce the same response

stimulus descrimination

the ability to differentiate b/w stimuli

operant conditioning

learning in which a voluntary response is strengthened or weakened, depending on the response’s favorable or unfavorable consequences

law of effect (Thorndike)

states that responses that lead to satisfying consequences are more likely to be repeated

reinforcement

process by which a stimulus increases the probability that a preceding behavior will be repeated

reinforcer

any stimulus that increases the probability that a preceding behavior will occur again

primary reinforcer

satisfies some biological need and works naturally

secondary reinforcer

stimulus that becomes reinforcing because of its associated with a primary reinforcer

positive reinforcer

stimulus added to the environment that brings about an increase in a preceding response

negative reinforcer

refers to an unpleasant stimulus whose removal leads to an increase in the probability that a preceding response will be repeated in the future

punishment

stimulus that decreases the probability that a prior behavior will occur again

positive punishment

weakens response by applying an unpleasant stimulus

negative punishment

consists of the removal of something pleasant

schedule of reinforcement

pattern of frequency and timing of reinforcement following desired behavior

continuous reinforcement schedule

behavior is reinforced every time it occurs

partial reinforcement schedule

behavior is reinforced some, but not all of the time

fixed ratio schedule

reinforcement is given only after a specific number of responses

variable ratio schedule

behaviors are reinforced after an average number of responses, when reinforcement will occur is unpredictable

fixed interval schedule

provides reinforcement for a response only if a fixed time period has elapsed

variable interval schedule

the time between reinforcements varies around some average rather than being fixed

stimulus control training

behavior is reinforced in the presence of a specific stimulus but not in its absense

shaping

process of teaching a complex behavior by rewarding closer approximations of desired behavior

behavior modification

technique for increasing the frequency of desirable behaviors and decreasing the incidence of unwanted ones

cognitive learning theory

focuses on how people think

latent learning

new behavior is learned but not demonstrated until some incentive is provided for displaying it

observational learning

learning by watching the behavior of another person or model

encoding

first stage in remembering something