Intro to Psych- Exam #2 (Biola University, Dr. Grace)

Sensation

detecting stimuli and transforming (encoding) them via receptor cells into neural messages.

-This is the process by which our sense receptors and nervous system receive and represent stimuli from the environment.

Absolute threshold

the minimum stimulation necessary to detect a particular stimulus (light, sound, pressure, taste, odor) 50% of the time.

Absolute threshold examples

1. Vision: Candle flame seen at 30 miles on a clear, dark night

2. Sound: Tick of a watch under quiet conditions at 20 feet (varies person to person)

Subliminal stimulations

stimulation that may be perceived although it is below one's absolute threshold for conscious awareness.

Affected by subliminal stimulations?

We are sometimes affected by subliminal messages, and can sometimes perceive them, but we are not persuaded by them. Backward masking exerts no influence, conscious or unconscious. Ex: Queen, Another One Bites the Dust (backwards, "It is fun to smoke marijuana")

Signal detection theory

the detection of a weak stimulus depends partly on a person's experience, expectation, motivation, and level of fatigue

Signal detection theory examples

1. Detectability: how loud, bright, or intense

2. Noise: random sounds, music, muscle twitch

3. Psychological states: expectation, hope, fear

Sensory Adaptation

diminished sensitivity to a prolonged, unchanging stimulus

Just noticeable difference

the minimum difference a person can detect between any two stimuli 50% of the time.

Focused on and researched by Weber.

The difference between naïve realism vs. constructive perception

1. Naïve realism: perceive objects as they really are

2. Constructive realism: create a cognitive understanding from what you see

Psychophysics

how the physical world gets inside of our brains/minds.

Bottom-up

take in sensory info and then assemble and integrate it

-What am I seeing or hearing?

Top-down

using models, ideas, and expectation to interpret sensory info

-Have I seen or heard it before?

-Try and predict what is coming next

Vision/Hearing

we can only see/hear a small spectrum of what is out there

The Chemical Senses

Taste and Smell—the interaction between senses

Pheromones

odorous secretions that transmit information

Pheromones examples

1. Ants: death

2. Dogs: mark territory

3. Humans: menstrual cycle

Perception

the organizing and interpreting of these transformed messages into meaningful ways

Gestalt

an organized whole. Our tendency to integrate pieces of information into meaningful wholes (means shape in German)

Figure ground

perceiving any object (the figure) as distinct from its surroundings (the ground)

-Used with radar in the military to hide planes

Depth perception

enables us to estimate an object's distance from us

-2d vs. 3d

Perceptual constancies

to recognize objects without being deceived by changes in their color, brightness, shape, or size

-top-down

Perceptual conflicts

brain turns something in 2d into 3d that wouldn't be possible

-The impossible doghouse in text

Contrast effects

illustrates the relational nature of perception

Motion perception

brain computes motion based partly on it assumption that shrinking objects are retreating and enlarging objects are approaching

-Also, perceives rapid series of slightly varying images as continuous movement

-shadows

Different types of groupings

proximity, continuity, closure

Proximity

we group nearby figures together. We see not six separate lines, but three sets of two lines

Continuity

we perceive smooth, continuous patterns rather than discontinuous ones.

-This pattern could be a series of alternating semicircles, but we perceive it as two continuous lines- one wavy, one straight

Closure

we fill in gaps to create a complete, whole object.

-Thus we assume that the circles in the photo are complete but partially blocked by the (illusory) triangle. Add nothing more than little line segments to close off the circles and your brain stops constructing a triangle

Perceptual adaptation

we can adjust to an artificially displaced or even inverted visual field. (Remember the example of the woman in the film who wore the inverted glasses. After a week she could ride a bike while wearing them.)

Perceptual set

a mental predisposition to perceive one thing and not another. We see things based on our experiences (i.e. role expectations)

Perceptual constancy

allows us to perceive an object as unchanging while the stimuli we receive from it may change

Size and shape constancy

-shape constancy: we perceive the form of familiar objects as constant even while our retinas receive changing images of them.

-size constancy: we perceive objects as having a constant size, even while our distance from them varies.

Extrasensory perception ESP

the claim that perception can occur apart from sensory input

Different types of ESP

telepathy, clairvoyance, and precognition

Definitions of different types of ESP

1. Telepathy: direct communication from one mind to another

-Twins

2. Clairvoyance: perception of remote (distant) events

3. Precognition: perception of future events

ESP in-class demonstration

"pick a number between 1 and 50"

"37" 😱 that was my number

"you have a tendency to pick 35 or 37"

-between 1-10, people tend to pick 7

Parapsychology

the study of unusual psychological phenome

Consciousness

the awareness of internal and external stimuli. Selective attention to ongoing perceptions, thought, and feelings

Controlled process

demand high concentration, alertness (i.e. taking an exam)

Automatic processes

"auto pilot" little awareness or attention (i.e. driving a stick shift)

Daydreams

reduced eye movement, high level of alpha activity

early theorists James & Freud

James- streams of consciousness vs. Freud- unconscious

Different Rhythms

Infradian rhythms, Circadian rhythms, Ultradian rhythms

Infradian rhythms

occur less frequently than once a day (i.e. menstrual cycle)

Circadian rhythms

occur approximately every 24 hours (i.e. sleep/wake cycle)

Ultradian rhythms

follow a 90-minute cycle throughout the day and during sleep. They are shorter in duration than circadian rhythms

Sleep disorders

apnea, night terrors, narcolepsy

Sleep apnea

cessation of respiration

-can't sleep and breath at the same time

-more likely for old people

-might be the cause of Sudden Infant Death Syndrome (SIDS)

Narcolepsy

A chronic sleep disorder that causes overwhelming daytime drowsiness

Night terrors (and Sleep Walking)

sleep attack

-Triggered by intense emotion- anger, surprise

-Genetic

-More common in young children- often outgrow

-Have no memory the next morning

-Happen in REM

Stages of sleep

1, 2, 3, 4 (then reverses: 4, 3, 2, REM)

Stage 1

drifting on edge of consciousness

i. Light sleep

ii. Awaken easily

iii. 15 minuets (12-12:15 if started at 12)

iv. alpha waves

Stage 2

clearly asleep

i. Sleep spindle (burst of activity)

ii. 12:20

Stage 3

hard to arouse

i. Breathing and pulse slowed

ii. 12:30

Stage 4

deep sleep

i. Delta waves

ii. Walking and talking in sleep, bed-wetting

iii. 45 minuets into sleep (12:45), halfway through Ultradian cycle

iv. if sleep deficient, can jump into stage 4

REM sleep

referred to as paradoxical sleep because our nervous system is highly active while our voluntary muscles hardly move

Why REM is important

-Can lose stage 4, not REM

-REM deprived greatly impacted

-REM rebound- go right into REM when deprived

-All other stages called NonREM

Different explanations of why we dream

psychoanalytic, physiological, computer analogy

Psychoanalytic

i. Freud- dreams are royal road to the unconscious

ii. Manifest (story of a dream) vs. latent content (underlying meaning of a dream)

iii. Criticisms- dreams don't have to mean anything

Physiological

i. Activation- synthesis hypothesis

ii. Spontaneous firing of neurons

iii. Cortex generates interpretation

iv. Criticism- takes away possibility to mean more

Computer Analogy

i. Christopher Evans

ii. Brain off-line while sleeping

iii. Mental housekeeping

Hypnosis

heightened state of suggestibility

Who discovered hypnosis it and theories about it

-Franz Mesmer

-Theories

i. Role Playing

ii. Altered state

-dissociation

Remember about hypnosis

hypnotized people usually behave in a similar fashion to un-hypnotized individuals