Chapter 3 Teaching Notes

 a. Sensation is the stimulation of sensory receptors and the transmission
of sensory information to the central nervous system.
 b. Perception is the process by which sensations are organized and
interpreted, forming an inner representation of the world.

 a. Absolute threshold is the weakest amount of a stimulus that can be told
apart from no stimulus at all.

 i. Method of constant stimuli- set of stimuli, different in stimuli, and
is done in random order.

 (1) Finds the absolute threshold of a person

 ii. Absolute threshold is the weakest amount of stimulation that can be
detected 50% of the time.
 iii. Psychophysical is the relationship between psychological and physical
events
 iv. Everyone has a different absolute threshold
 v. A persons absolute threshold may differe on certain days and occasions
 vi. Absolute threshold lets us see the world as we see it today

 (1) Ears more sensitive we might here molecules collide
 (2) Eyes- sensitive to longer wavelengths- we might see infrared

 b. Difference Threshold- The minimum difference in the magnitude of 2
stimuli required to tell them apart

 i. When you can tell the difference between two things 50% of the time.
 ii. JND- Just noticable difference- minimum amount of energy to tell the
difference

 (1) Webers constant- intensity of light change by 1/60 to notice difference

 c. Signal detection theory- takes into consideration the human elements in
sensation and perception.

 i. Several factors to notice a stimuli (signal) or difference between two
stimuli (signals)

 (1) Intensity of stimuli
 (2) How well the wanted stimuli is distinguished from background noise, or
unwanted stimuli that interferes with perception of the desired stimuli
 (3) Quality of a persons sensory system

 (a) The sharpness and acuteness- developed or diminished due to illness or old age

(4) Psychological factors

 (a) motivation, expectations, and learning

 d. Sensory adaptation refers to the processes by which we become more
sensative to stimuli of low magnitude and less sensitive to stimuli of
relatively constant magnitude.

 i. Sensitization-+-becoming more sensitive to stimulation
 ii. Desensitization-,-,-becoming less sensitive to stimulation

 a. Most important sense

 a. Visible light- triggers visual sensations
 b. Visible light is a small part of a spectrum of electromagnetic energy,
or wavelengths
 c. Longest to shortest wavelengths- Roy G. Biv
 d. Hue is the color of the wavelength of visible light

 a. Cornea-covers the front of the eyes surface
 b. Iris- colored part of eye

 i. Amount of light that passes through depends on the size of the muscle

 c. Pupil is the opening in the iris

 i. Size automatically adjust to the amount of light

 (1) less light- becomes big
 (2) more light- becomes small

 d. Lens-light goes through iris then lens

 i. Lens changes it thickness to fous the object according to the objects
distance
 ii. Image is then projected onto the retina
 iii. People who squint adjust the thickness of the lens to get a clearer
picture

 e. Retina-sends image to brain

 i. Photoreceptors

 (1) rods and cones
 ii. Several layers of cells
 (1) layers made up of rods, cones, bipolar cells, ganglion cells.
 (2) light travels past ganglion and bipolar cells and stimulate the rods
and cones
 (3) rods and cones then send neural messages to bipolar cells and then to
the ganglion cells
 (4) Axons of the ganglion cells make up the optical nerve
 (5) message from ganglion sent to the occipital lobe

 f. Fova-most sensitive part

 i. Made up of cones
 ii. Receptor cells are more densely packed here

 g. Blind spot

 i. Where ganglion cells accumulate to make the optic nerve

 h. Rods and Cones

 i. Photo receptors in the retina
 ii. About 100 million rods, 5 million cones
 iii. Cones- more in back, less in front
 iv. Rods- more in front, less in back
 v. Rods- deal with black and white, intensity of light
 vi. Cones deal with color

 i. Light adaptation

 i. Dark adaption- adjusting to lower lighting

 (1) cones take 10 minutes to adapt
 (2) rods take about 45 minutes to adapt
 (3) adaptation to bright light happens a lot faster

 a. Warm and cool colors

 i. Warm jump out to people
 ii. Cool recedes in a picture

 b. Saturation is the pureness of a color
 c. Complementary colors- colors that are across from each other on the
color wheel

 i. When mixed make gray

 d. Light source of all colors
 e. Pigments come from light

 i. Pigments absorb all colors except the one that they want to look like

 f. Primary colors

 i. Red, blue, yellow
 ii. Cannot be produced by mixing pigments

 g. Secondary colors

 i. Created by mixing primary colors

 h. Tertiary colors

 i. Created by mixing primary and adjoining secondary colors

 i. After images occur when persistent sensations of color are followed by
perception of the complementary color when the first color is removed
 j. Analogous colors

 i. Lie next to one another on the color wheel forming families of colors like yellow and orange, orange and red, and green and blue

 a. Trichromatic theory

 i. 3 different photoreceptors- the primary colors
 ii. When other colors are seen two photoreceptors are stimulated at the
same time
 iii. Also known as young-helmholtz theory after Thomas Young and Hermon von Helmholtz

 b. Opponent-process theory

 i. 3 types of photoreceptors
 ii. Blue-yellow, red-green, dark-light
 iii. Only see one color at a time

 a. Trichromat- no color blindness
 b. Monochromats

 i. Only tell difference between light and dark

 c. Dichromats

 i. Tell difference between 2 colors

 (1) red and green or blue and yellow

 a. Relies on our knowledge, expectations, and motivations
 b. How we interpret the world around us.
 c. Principle of closure, how gestalt psychologists explain the tendency to perceive a complete or whole figure even when there are gaps in the sensory input

 a. Figure-ground perception

 i. How we see things compared to their background
 ii. An ambiguous relationship makes our perception unstable because it can be interpreted two ways

 (1) rubin vase and necker cube are examples

 a. Proximity- nearness. The perceptual tendency to group together objects
that are near one another
 b. Similarity-the perceptual tendency to group together objects that are
similar in appearance
 c. Continuity- the tendency to perceive a series of points or lines as
having unity
 d. Common Fate-the tendency to perceive elements that move together as
belonging together

 a. How we see things as moving
 b. Psychologist have studied how some illusions of movement are made

 i. The autokinetic effect- the tendency to perceive a stationary point of
light as moving in a dark room
 ii. Stroboscopic motion-the illusion of movement is provided by the
presentation of a rapid progression of images of stationary objects
 iii. Phi phenomenom- the perception of movement as a result of sequential presentation of visual stimuli

 (1) scoreboard
 (2) New York stock exchange electronic "ticker"

 a. Monocular cues- cues that can be perceived by one eye, to create an
illusion of depth

 i. Cues like clearness, interposition, shadows, and texture gradient,
cause certain objects to be farther away than other objects
 ii. Distant objects take up less room on the retina
 iii. Perspective- the tendency to perceive parallel lines as coming closer
or converging as they recede from us
 iv. Interposition- an object is closer because it is overlapping the other
object
 v. Shadowing- a monocular cue for depth based on the fact that opaque
objects block light and produce shadows
 vi. Texture gradient- a monocular cue for depth based on the perception
that closer objects appear to have rougher (more detailed) surfaces
 vii. Motion parallax- a monocular cue for depth based on the perception that nearby objects appear to move more rapidly in relation to our own motion

 b. Binocular cues

 i. Cues that involve both eyes
 ii. Retinal disparity- a binocular cue for depth based on the difference
in the image cast by an object on the retinas of the eyes as the object
moves closer or farther away.
 iii. Convergence- a binocular cue for depth based on the inward movement of the eyes as they attempt to focus on an object that is drawing nearer.

 a. Size canstancy- the tendency to perceive an object as being the same
size even as the size of its retinal image changes according to its distance

 i. Anthorpologist Colin Turnbull, African Pygmy- kenge, buffalo

 (1) kenge only see animals up close

 b. Color constancy- the tendency to perceive an object as being the same
color even though lighting conditions change its appearance
 c. Brightness constancy- the tendency to perceive an object as being just
as bright even though lighting conditions change its intensity
 d. Shape constancy- the tendency to perceive an object as being the same
shpae although the retinal image varies in shape as is rotates

 a. Page 120- explain the illusions

 a. Sound travels through the air in the form of waves
 b. Sound caused by change of air pressure. Air pressure changed by
vibrations caused by sound
 c. One wave is equal to a cycle of the compression and expansion of air
 d. Human ear sensitive to 20-20,000 cycles per second

 a. Pitch

 i. Hertz (Hz)

 (1) 1 hertz is equal to one cycle per second

 ii. Higher the hertz the higher the pitch is

 b. Loudness

 i. Louder sounds have a wave with greater amplitude or height
 ii. Decibel (dB0

 (1) 0 dB is the human threshold. 0 dB is being able to hear a watch tick
20 feet away from you in a quiet room
 (2) 85-90 dB cause hearing damage

 iii. Consonant- when two combined sounds are in harmony
 iv. Dissonant- unpleasant combination of tones

 a. Overtones result from vibrations elsewhere in the instrument and
contribute to the quality or richness of a sound
 b. Timbre is the quality or richness of a sound

 a. Noise is the combination of dissonant sounds
 b. White noise- a combination of many different frequencies but sounds
good

 a. Outer ear

 i. Funnels sound waves to the eardrum
 ii. Eardrum- vibrates in response to sound waves

 (1) transfers vibrations to middle and inner ear

 b. Middle ear

 i. Contains eardrum, hammer, anvil, and the stirrup

 (1) get their name because of their shape

 ii. Functions as an amplifier- increases the magnitude of air pressure
 iii. Stirrup attached to the oval window

 (1) round window out- oval window in
 (2) round window in- oval window out
 (3) this is done to balance air pressure inside the ear

 c. Inner ear

 i. Oval window transmits vibrations to the cochlea
 ii. Cochlea contains 3 fluid filled membranes
 iii. 1 membrane is the basilar membrane
 iv. Organ of corti, AKA command post, is attached to basilar membrane

 (1) thousand of hair cells bend in response to vibrations
 (2) bending of receptor cells send a neural impulse that is transmitted by
31,000 neruons that form the auditory nerve.  Information is sent to the Temporal lobe

 a. The ear that has the loudest sound in it is the direction a sound is
coming from
 b. Turn head slightly to hear sounds that come from in front or behind us

 a. Place theory

 i. Pitch of a sound is determined by the place along the basilar membrane
that vibrates in response to it
 ii. Higher pitch, the closer the responsive neurons lie to the oval window

 b. Frequency theory

 i. Pitch perception depends on the stimulation of neural impulses that
match the frequency of the sound waves

 c. Duplicity theory

 i. Combines the two previous theories

 a. Odor- sample of the actual substance being sensed
 b. Odors detected by neurons in the olfactory membrane
 c. Info about odors is sent to the olfactory nerve
 d. Various theories state there are several basic odors

 i. Flowery, minty, musky, camphoraceous, ethereal, pungent, putrid
 ii. Other odors are made by combing the basic odors

 e. Able to smell when a substances molecules fit the shapes of receptor
sites
 f. Anosmia- "smell blindness"

 i. Caused by damage to receptor site

 g. Smell adapts to odors pretty quickly

 a. McClintock caused the reproductive cycles of female rats to converge by
circulating air between cages
 b. Pheromones

 i. Some animals secrete to induce mating
 ii. Some people respond to pheromones but people don't need it.

 a. 4 primary taste qualities

 i. Sweet, sour, salty, bitter

 b. Taste sensed through taste cells
 c. Taste cells located on taste buds
 d. Have about 10,000 taste buds

 i. Mostly located at the sides and back of the tongue

 e. Different part of tongue taste different taste
 f. Decline in taste as you get older

 i. Lose taste cells
 ii. Decline in sense of smell

 a. Touching sensation fades quickly
 b. .5 million receptors for touch and pressure spread through the body
 c. Some parts of the body are more sensitive
 d. Two-point threshold

 i. Smallest point between two rods until a person can tell there are two rods

 a. Things feel either warm or cold depending on body temperature
 b. Body can adapt to changes in temperature
 c. Cold fires cold receptors
 d. Warm fires warm receptors
 e. Hot fires both receptors

 a. Pain receptors tell us something is wrong with our body
 b. Various chemicals released to the breain

 i. Prostaglandins, bradykinin, and P

 c. Pain signals sent to the thalamus
 d. Gate theory

 i. Scratching helps relieve pain because scratching competes for neurons

used by pain
 e. Endorphines are released due to pain
 f. Accupunture- put a pin at a certain spot to relieve pain
 g. Placebo effect
 i. Expectations that you will be relieved by a pill come true, even when you take a placebo

 a. The sense that informs you about the position and motion of parts of
your body

 a. Vestibular sense tells you if you are upright
 b. semicircular canals monitor your body's motion and position in relation
to gravity

 a. Precognition- being able to foresee the future.
 b. Psychokinesis- ability to manipulate objects by thought processes
 c. Extrasensory perception- perception of objects and events in the
absence of stimulation.
 d. Telepathy- direct transference of though from one person to another
 e. Clairvoyance- being able to see things in the absence of sensory
stimulation