Psychology Unit V: Sensation & Perception

SENSATION & PERCEPTION

Sensation

• window into the world
• process by which our sensory receptors and nervous system receive stimulus from the environment 
• processing of stimuli

Perception

• interpret what comes into window
• essentially an interpretation and elaboration of sensation
• organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

Visual Capture

• tendency for vision to dominate other senses

Gestalt Psychology

• "means an organized whole"
• these psychologists emphasize our tendency to integrate pieces of info into meaningful wholes

Gestalt Philosophy

• whole is greater than the sum of its parts

Figure - Ground Relationship

• the organization of the visual field into objects (figures) that stand out from their surroundings (ground)

Grouping

• perceptual tendency to organize stimuli into groups that we understand

1. Proximity: nearby objects together
2. Similarity: similar figures together
3. Continuity: continuous patterns together
4. Connectedness: uniform & linked figures group together

Depth Perception

• ability to see objects in 3D although images that strike the retina are 2D
• allows us to judge distance

Binocular Cues

• depth cues that depend on two eyes
• Retinal Disparity: binocular cue for seeing depth
• the closer an object come to you the greater the disparity is between two images

Monocular Cues

• depth cues that depend on one eye
• Interposition: if something is blocking our view, we perceive it as closer 
• Relative Size: if we know two objects are similar in size, the one that looks smaller is further away
• Relative Clarity: we assume hazy objects are farther away

1. Texture Gradient: the coarser it is, the closer it is
2. Relative Height: things higher in our field of vision, look farther away
3. Relative Motion: things closer look like the move more quickly
4. Linear Perspective: parallel lines seem to converge at a distance
5. Light & Shadow: dimmer objects appear farther away because they reflect less light

Phi Phenomenon

• illusion of movement created when two or more adjacent lights blink on and off in succession

Perceptual Consistency

• perceiving objects as unchanging even as illumination and retinal images change

Sensation & Perception

Bottom Up vs. Top Down Processing

• Bottom Up: analysis that begins with the sense receptors and works up to the brain's integration of sensory information
• Top Down: information processing guided by higher - level mental processes, when we construct perceptions drawing on our experience and expectations

Absolute Threshold

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

Difference Threshold

• the difference that a person can detect between two stimuli 
• aka: Just Noticeable Difference

Weber's Law

• idea that to perceive a difference between two stimuli, they must differ by a constant percentage , not a constant amount. 

Signal Detection Theory

• predicts how we detect a stimulus amid other stimuli
• assumes that we do not have an absolute threshold
• we detect stuff based on experience, motivation, and fatigue level.

Subliminal Stimulation

• below one's absolute threshold for conscious awareness

Transduction

• transforming signals into neural impulses 
• information goes from the senses to the thalamus, then to various areas of the brain

Sensory Adaptation

• diminished sensitivity as a result of constant stimulation

Selective Attention

• focusing of conscious awareness on a particular stimuli

Cocktail Party Effect

• ability to listen to one voice among many

Pheromones

• chemical messengers that are picked up through our sense of smell

Touch

• receptors located in skin
• Gate Control Theory of Pain: where nervous system blocks or allows pain signals to pass to the brain

Vestibular Sense

• tells where the body is oriented in space
• sense of balance

Kinesthetic Sense

• tells where body parts are 
• receptors located in muscles and joints

Vision

Transduction

• conversion of one form of energy to another

Wavelength

• distance from the peak of one light wave to the peak of the next
• distance determines the hue (color) of the light we perceive

Intensity

• amount of energy in a light wave 
• determined by height of a wave
• the higher the wave, the more intense light is

Parallel Processing

• processing of several aspects of a problem simultaneously 

Young Helmholtz Trichromatic Theory

• three color theory
• realized that any color can be created by combining the light waves of three colors (primary) 
• red, green, and blue
• most color blind people lack cone receptor cells for one or more primary colors

Rods

• facilitate black & white vision

Cones

• facilitate color vision

Opponent Process Theory

• we can't see certain colors together in a combination

Hearing (Audition)

Frequency

• number of complete wavelengths that pass through a point at a given time
• determines pitch of a sound

Amplitude

• how loud the sound is
• the higher the crest of the wave is, the louder the sound is
• measured in decibels

Helmholtz's Place Theory

• we hear different pitches because different sound waves trigger activity at different places
• along the cochlea's basilar membrane 

Frequency Theory

• we sense pitch by the basilar membrane vibrating at the same rate as the sound

Hearing Loss

• Conduction: caused by damage to the mechanical system of ear
• Sensorineural: damage to cochlea's receptor cells or to auditory nerves

Smell & Taste

• chemical senses

Sensory Interaction

• the principle that one's senses many influence another

Papillae 

• those bumps on our tongue
• help grip food while chewing
• contain taste buds

Psychology Unit VI: Sleep Disorders

SLEEP DISORDERS

Insomnia

• recurring problems in falling asleep or staying asleep

Narcolepsy

• uncontrollable sleep attacks 
• lapses directly into REM sleep (stress or joy)

Sleep Apnea

• temporary cessations of breathing during sleep and momentary awakening

Night Terrors

• high arousal and appearance of being terrified
• stage 4, not REM, not often remembered

Sleepwalking

• somnambulism
• most often occurs during deep non - REM sleep (stage 3 or 4) early in the night

Psychology Unit VI: Stages of Sleep

STAGES OF SLEEP

Stage One

• kind of awake and asleep
• a few minutes
• eyes roll slightly
• brain produces Theta waves

Stage Two

• "baseline" of sleep
• part of a 90 minute cycle and occupies about 45 - 60% of sleep
• more Theta waves get progressively slower
• begin to show sleep spindles

Stages Three to Four 

• slow wave sleep
• produce Delta waves
• if awoken, can be groggy
• may last 15 - 30 minutes 
• "Delta" sleep is deepest stage of sleep
• restore body's growth hormones and good health

Stage Five REM Sleep

• Rapid Eye Movement
• called Paradoxical Sleep
• brain is active
• dreams occur
• body is essentially paralyzed 
• composes about 20 - 25% of a normal night's sleep
• quicken breathing, heart rate, and brain waves
• vivid dreams can occur
• from REM sleep, you go back to Stage Two

Psychology Unit VI: States of Consciousness

STATES OF CONSCIOUSNESS 

Sleep

• state of consciousness
• we are less aware of our surroundings

Levels (three)

• conscious
• subconscious
• unconscious

Biological Rhythms

• annual cycles: seasonal variations
• 28 days: menstrual cycle
• 24 hour: our circadian rhythm
• 90 minutes: sleep cycles

Circadian Rhythm

• our 24 hour biological clock
• our body temperature and awareness changes throughout the day

Sleep Stages

• five stages 
• takes about 90 - 100 minutes to pass through five stages 
• brain's waves will change according to sleep stage you're in 
• first four stages known as NREM sleep
• fifth stage is called REM sleep

Psychology Unit V: Learning

LEARNING 

Three Main Types of Learning

• Conditioning: classical & operant
• Learning: observational & latent
• Learning: abstract & insight

Associative Learning

• learning that certain events occur together

Classical Conditioning

• acquisition
• extinction
• spontaneous recovery
• generalization
• discrimination

Conditioned Stimulus

• an originally irrelevant stimulus, that after association with the UCS, comes to trigger a response

Conditioned Response

• the learned response to a previously neutral stimulus

Unconditioned Stimulus 

• naturally and automatically triggers a response

Unconditioned Response

• the unlearned, naturally occurring response to the the UCS

Acquisition

• initial stage of learning
• phase where neural stimulus is associated with the UCS so that the neutral stimulus comes to elicit the CR (becoming the CS)
• Cs is before UCS and they occur together in timing

Extinction

• diminishing of a conditioned response 
• will eventually happen when the UCS does not follow the CS 

Spontaneous Recovery

• the reappearance after a rest period, of an extinguished conditioned response 

Generalization

• tendency once a response has been conditioned for stimuli similar to the CS to elicit similar responses

Discrimination

• learned ability to distinguish between a CS and other stimuli that does not signal UCS 

Mood - Congruent Theory

• tendency to recall experiences that are consistent with one's current mood (good or bad)
• depressed = sad memories recalled
• moods affect the way you interpret other people's behavior

Operant Conditioning

• type of learning in which behavior is strengthened if followed by reinforcement or diminished if followed by punishment

Classical vs. Operant

• both use acquisition, discrimination, spontaneous recovery, generalization, and extinction
• classical conditioning is automatic (respondent behavior) 
• operant conditioning involves behavior where one can influence their environment with behaviors which have consequences (operant behavior) 

Edward Thorndike

• Law of Effect: rewarded behavior is likely to recur (operant behaviors)

B.F. Skinner

• Operant Conditioning 

Shaping

• reinforcers guide behavior closer and closer towards a goal
• procedure in operant conditioning

Reinforcer

• event that strengthens the behavior it follows
• two types: positive and negative

Positive Reinforcement

• strengthens a response by presenting a stimulus after a response

Negative Reinforcement 

• strengthens a response by reducing or removing an aversive stimulus 

Primary Reinforcer

• innately reinforcing stimulus

Conditioned (Secondary Reinforcer)

• stimulus that gains its reinforcing power through its association with a primary reinforcer

Continuous Reinforcement

• reinforces the desired response every time it occurs

Partial Reinforcement

• reinforces a response only part of the time 
• acquisition is slower
• greater resistance to extinction

Fixed - Ratio Schedule

• reinforces a response only after a specified number of responses 

Variable - Ratio Schedule

• schedule of reinforcers that reinforces a response after an unpredictable number of responses

Fixed - Interval Schedule

• schedule of reinforcement that reinforces a response only after a specified time has elapsed

Variable - Interval Schedule

• that reinforces a response at unpredictable time intervals 

Punishment

• meant to decrease a behavior
• positive punishment: addition of something unpleasant 
• negative punishment (omission training): removal of something pleasant 
• works best if harsh or when done immediately after behavior

Token Economy

• every time a desired behavior is performed, a token is given
• trade token for prizes (reinforcers) 
• used in homes, prisons, mental places, and schools

Observational Learning

• Bandura & BOBO Doll
• we learn through modeling behavior from others 
• operant learning + operant conditioning  = social learning theory

Insight Learning

• Wolfgang Kohler & Chimpanzees
• some animals learn through the "ah ha" experience

Latent Learning

• Edwards Toleman
• sometimes learning is not immediately evident 
• hidden

Psychology Unit VI: Memory

MEMORY

• the persistence of learning over time through the storage and retrieval of information

Process

• encoding: processing of information into the memory system, getting information out of our heads
• storage: retention of encoded material over time
• retrieval: getting the information out of memory storage

Ways to Encode

• automatic: unconscious encoding of incidental information, encode space, time, words, and meaning without information, things can become automatic with practice
• effortful: requires attention and conscious effort, rehearsal is the most common effortful processing technique, through effortful processing what was effortful becomes automatic

Recall vs. Recognition

• recall: you must retrieve information from memory, an example is fill - in - the - blank
• recognition: identify the target from possible targets, an example is multiple choice

Flashbulb Memory

clear moment of an emotionally significant moment or event

Types of Memory

• sensory
• short - term
• long - term

Sensory

• immediate, initial recording of sensory information in the memory system
• stored for an instant, most gets unprocessed 
• lasts half a second for visual
• lasts 2 - 4 seconds for auditory 
• capacity of storage is large
• any information not transferred is lost

Short - Term Memory

• holds a few items briefly 
• remember seven digits at a time
• information will be stored into long - term or forgotten
• aka: working memory
• limited capacity
• 3 - 12 seconds
• digits are more easily remembered than letters
• has three parts: audio, visual, and integration of both (controls where attention lies)

Long - Term Memory

• permanent and limitless storehouse

Encoding

• next - in - line effect: we seldom remember what the person has just said or done if we are next
• information minutes before sleep is seldom remembered; in hours before sleep, it is well remembered
• taped information played while asleep is registered by ears, but we do not remember it 

Spacing Effect

• we encode better when we study or practice over time

Serial Positioning Effect

• our tendency to recall best the first and last items in a list

Types of Encoding

• Semantic: meaning, like meaning of words
• Acoustic: sound, especially the sounds of words
• Visual: picture images

Self - Reference Effect

• we remember things when they are used to describe ourselves
• how we encode meaning very well

Tricks to Encode

• imagery: mental pictures

Chunking

• organize items into familiar, manageable units
• often it will occur automatically 

Iconic Memory

• momentary sensory memory of visual stimuli, a photo like quality lasting about a second
• we also have an echoic memory for auditory stimuli

Storing Memory

• long - term potentiation: long - lasting enhancement in signal transmission between two neurons, results in stimulating them synchronously
• they learn to fire together and get better at it...creating a memory 

Hippocampus

• damage disrupts memory
• right is visual and locations
• left is verbal

Types of Retrieval Failure

• proactive interference: disruptive effect of prior learning on the recall of new information
• retroactive interference: disruptive effect of new learning on the recall of old information

Motivated Forgetting

• repression: basic defense mechanism that banishes anxiety - arousing thoughts, feelings, and memories from conscious

Déjà Vu

• eerie sense you have experienced something before
• what is occurring is that the current situation cues past experiences that are very similar to the present one - you mind gets confused

Psychology Unit V: Intelligence

INTELLIGENCE

• the ability to learn from experience, solve problems, and use knowledge to adapt to new situations

Multiple Intelligences

• idea that studying savants
• savants: when a person has limited mental ability, but is exceptional in one area

Gardner's Multiple Intelligences 

1. visual/spatial
2. verbal/linguistic
3. logical/mathematical
4. bodily/kinesthetic
5. musical/rhythmic
6. interpersonal
7. intrapersonal
8. natural

Factor Analysis

• statistical procedure that identifies clusters of related items on a test

Gardner Simplified

• analytical: academic & problem solving
• creative: generating novel ideas
• practical: required for everyday tasks where multiple solutions exist

Emotional Intelligence

• ability to perceive, express, understand, and regulate emotions

How Do We Assess Intelligence?

• Alfred Binet & Theodore Simon
• mental age: what a person of a particular age should know
• discovering mental age can predict future performance
• use test to help children, not label them

Brain Size and Intelligence, Is There a Link?

• small + .15 correlation between head size and intelligence scores (relative to body size)
• using a MRI we found + .44 correlation with brain size and IQ score

IQ Test

• Terman
• IQ = (mental age / chronological age) X 100

Brain Function & Intelligence

• higher performing brains use less active than lower performing brains (use less glucose)
• neurological speed is also a bit quicker

Wechsler Adult Intelligence Scale (WAIS)

• consists of 11 subtests and cues us in to strengths by using factor analysis

Standardization

• the test must be pre - tested to a representative sample of people and form a normal distribution or bell curve

Aptitude vs. Achievement Tests

• Aptitude: a test designed to predict a person's future performance, the ability for that person to learn
• Achievement: a test designed to assess what a person has learned

Flynn Effect

• intelligence test performance has been rising

How Do We Conduct Intelligence Tests?

• they must be standardized, reliable, and valid

Validity

• the extent to which a test measures what it is supposed to measure

Content Validity

• does the test sample a behavior of interest

Predictive Validity

• does the test predict future behavior

Test Bias?

• do discriminate
• some argue that their sole purpose is to discriminate