the detection of physical energy emitted or reflected by physical objects

located in sense organs: eyes, ears, tongue, nose, skin and internal body issues

cells located in the sense organs

report to the sensory nerves in the peripheral nervous system which report to the cells of the brain

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

do not explain variations of experience within a different sense

the smallest quality of physical energy that can be reliably detected by an observer

50% chance of detection

difference threshold

just noticeable difference

sensory process

decision process

depends on the intensity of the stimulus

influenced by the observer's response bias 

cornea

lens

iris

pupil

• protects the eye and bends incoming light rays toward the lens behind it
• focuses incoming light by moving closer to or farther from the shutter opening
• the part of the eye that gives the eye color and whose muscles control the amount of light that gets into the eye
• widens or closes to allow light to enter into the eye

the visual receptors located in the back of the eye

an extension of the brain

rods

visual receptors that respond to dim light

long and narrow

enable us to see in dim light

handle peripheral vision

visual receptors involved in color vision

cone shaped

the center of the retina where vision is sharpest

contains only cones

a process by which visual receptors become maximally sensitive to dim light

the cones adapt quickly but never very sensitive to the dim light

the rods adapt slower but are the most sensitive

the theory of color perception that proposes three mechanisms in the visual system, each sensitive to a certain range of wavelength

one is blue, the other green, the last is red

among the first to study how people organize the world visually into meaningful units and patterns

"the whole is more than the sum of its parts"

when an object is interposed between the viewer and a second object, partly blocking the view of the second object, the object is perceived as being closer

when two lines known to be parallel appear to be coming together or converging, they imply the existence of depth

the dimension of auditory experience related to the intensity of a pressure wave

measured in decibels (dB)

the dimension of auditory experience related to the frequency of a pressure wave; the height or depth of a tone

one cycle is known as a Hertz

a structure in the cochlea containing hair cells that serve as receptors for hearing

contains important receptors and cilia

cochlea

basilar membrane

auditory nerve

snail shaped, fluid- filled organ in the inner ear containing the organ of Corti where the receptors are located

embedded with hair cells within the cochlea and stretches across the cochlea

carries signals from the hair cells to the brain

supertasters

tasters

nontasters

find saccharin, caffeine, broccoli, and many other substances as unpleasantly bitter

detect less bitterness 

detect no bitterness

Gate-Control Theory of Pain

Ronald Melzack and Patrick Wall

• pain impulses must get past a gate to the spinal chord
• normally the gate is shut by the larger fibers
• when injured the larger fibers are injured and smaller fibers open the gate allowing the pain to reach the brain

emphasizes the role of the brain controlling the gate

doesn't fully explain the many instances of severe chronic pain that occur without any sign of injury or diease