sensation and perception

sensation

detection of raw, basic information from the outside world

perception

interpretation and organization of transmitted information into meaningful objects and concepts

1. stimulus energy

2. sensory receptors

3. neural impulses

4. brain

sensation to perception

physical stage

action of one or more physical stimulus on a sense organ

physiological stage

internal processing of received stimulus, which operate within the receptor and the nervous system

absolute threshold

smallest amount of stimulus that must be present in order to be discerned

terminal threshold

maximum physical energy that can be still detected by a sense organ, anything beyond which already evokes a different sensation or no sensation at all

differential threshold

minimum amount of stimulus energy required to recognize the difference between two stimuli

sensory adaptation

reduction in sensitivity to stimulation as stimulation persists through time

modality

stimulus belongs based on the nature of the physical energy

quality

different experiences within the same modality

intensity 

degree within the same quality

duration

length of time a sensation is experienced in the consciousness

reaction time

time between application of sensory stimulus and recognition of sensory experience

the riddle of separate sensations 

sense receptors: specialized cells that convert physical energy in the environment or the body to electrical energy that can be transmitted as nerve impulses to the brain

doctrine of specific nerve energies

diff sensory modalities exist because signals received by the sense organ stimulate different nerve pathways leading to different areas of the brain

visual sense

shapes and colors, spatial arrangements, objects near and far away.

physical stage

stimuli that register as light in our eyes are electromagnetic radiation waves, our eyes happen to be sensitive and capable of responding

visible spectrum

rage of wavelengths that humans are sensitive to

hue

visual experience to specified by color names and related to wavelength of light

brightness

lightness and luminance; related to the amount of light emitted

saturation

vividness or purity of color; visual experience related to the complexity of light waves

cornea 

protects eye and bends light toward lens

lens

focuses on objects by changing shape

iris

controls amount of light that gets into eye

pupil

widens or dilates to let in more light

retina

neural tissue lining the back of the eyeball’s interior, contains receptors for vision

rods

visual receptors that respond to dim light

cones

visual receptors involved in color vision. humans have 4 types of cones

form perception

gestalt principles describe the brains organization of sensory building blocks into meaningful units and patterns

gestalts view of perception

“the whole is more than a sum of its parts

law of pragnanz

individual organize their experience in as simple, concise, symmetrical, and complete manner as possible

simplicity

tendency to perceive patttern in the most basic manner possible

figure-ground

distinguishing between a figure and a background

proximity

elements tend to be grouped together according to their nearness

similarity

items similar in some respect tend to be grouped together

continuity

based on smooth continuity, preferred to abrupt changes of direction

closure

items are grouped tgt if they tend to complete a figure

symmetry

prefer to perceive objects as mirror images

monocular cues

visual cues to depth or distance that can be used by one eye alone

texture gradients

grain of item

relative size

bigger is closer 

interposition 

closer are in front of the other objects

linear perspective

parallel lines converge in distance

aerial perspective

images seem blurry father away

motion parallax

objects gets smaller at decreasing in speed in distance

ames room

room that makes people seem to change size as they move around to it, not rectangular

binocular cues

visual cues to depth or distance that require the use of both eyes

convergence 

turning inward of the eyes, occurs when they focus on a nearby object

retinal disparity

slight difference in lateral separation between two objects as seen by the left and right eye

shape constancy

even tho images cast shadows of diff shapes, we still know the shape

visual illusions

muller-lyer illusion: tend to perceive the line as slightly longer than the other

ponzo illusion

linear perspective provides context

perceptual illusions

we cannot perceive what does exist

we perceive things that do not exist

we perceive what cannot be there

trichromatic theory

young and helmholtz proposed that the eye detects 3 primary colors

opponent process theory

assumes that the visual system treats pairs of colors as opposing or antagonistic. inhibited by a color, have a burst of activity when it is removed

hearing

what we hear; an ear on the world; constructing the auditory world

frequency

number of vibrations per second

amplitude

amount of contraction and expansion as represented by the amount which the curve departs from the base line

loudness

intensity of a pressure wave

pitch

frequency of pressure wave

timbre 

complexity of pressure wave

taste 

Gustation is the special sense associated with the tongue.

papillae

knoblike elevations on the tongue, containing tastebuds

tastebuds

nest of taste receptor cells

smell

airborne chemical molecules enter the nose and circulate through the nasal cavity.

gate-control theory of pain

Experience of pain depends (in part) on whether the pain impulse gets past neurological “gate” in the spinal cord and thus reaches the brain.

neuromatrix theory of pain

brain is capable of generating pain (and other sensations) in the absence of signals from sensory nerves

kinesthesis

sense of body position and movement of body parts; also called kinesthesia.

equilibrium

sense of balance

Semicircular Canals

organs in the inner ear, which contribute to equilibrium by responding to rotation of the head.

subliminal perception

perceiving without awareness

subliminal perception

perception vs persuasion

extrasensory perception

ability to perceive smth without ordinary sensory information

telepathy

mind to mind communication

clairvoyance 

perception of remote events 

precognition 

ability to see future events

parapsychology

study of purported psychic phenomena such as ESP and mental telepathy.