Sensory Processes Flashcards
Physical stimuli
light and sound are examples of
Chemical information
taste and smell are examples of
Mechanical information
touch and hearing are examples of
Electromagnetic information
vison is an example of
Psychophysics
the psychology of sensation to the physics of sensation
uses a measure called just noticeable difference (JND)
threshold
minimum amount of physical stimulus intensity necessary for detection
Stevens Power Law
the relation between the physical and the psychological intensity of a stimulus is linear on a log/log coordinate scale
Loudness
refers to the amplitude of change of the stimulus
Ultrasound
heard by rodents and bats
higher than 20,000HZ
Pitch
the psychological variable that is related to the physics; dimension of frequency
Infrasound
lower than 20 HZ
Hearing range for a human
20-20,000 Hz
Eardrum
in the inner ear responds to vibration and in turn vibrations are conveyed through the middle ear ossicles (hammer, anvil, stirrup) into the cochlea
Cochlea
snail shaped organ in the inner ear filled with fluid and the fluid vibrates when the ossicles vibrate
Ossicles
tiny bones made-up of the hammer anvil and stirrup vibrate when the eardrum vibrates
Basilar membrane
in the cochlea also vibrate in response to sound
sensory receptors for hearing
tiny hairs which have cilia transduce vibrations into neural signals
frequency principle
the frequency action potentials matches the frequency vibrations
*most of the sound range neurons cannot firs fast enough to track the sound pressure fluctuations
place principle
explains the transduction from frequency into psychological pitch
Electromagnetic spectrum
physical stimulus is a small fraction of this
Visible spectrum
the part of the spectrum that humans detect
retina
performs transduction
optic nerve
leaves eye and conveys information to the brain
optic chiasm
partial crossing of nerves
LGN lateral geniculate nucleus
visual relay area of the thalamus, innervates primary visual cortex
occipital lobe
visual association cortex
Rods
in the retina as sensory receptor for black and white and nocturnal vision
Cones
in the retina for color vision
fovea (fovea centralis)
in the center portion of the retina that contains the highest concentration of receptor cells
blind spot (scotoma)
does not have any sensory receptor cells because it is the area where all the axons from the retina cells bundle together to form the optic nerve and here is no transduction of light
Receptor layer
the back layer has rods and cones
bipolar cells
the next layer, form the synapse with the receptors on one side and with ganglion cells in the next layer
ganglion cells
bundle together in the retina exit the eye through the blind spot and become the optic nerve
visual field
the two eyes have and overall what
dark adaption
occurs in respons to low levels of light, reflects the process in which visual threshold gradually gets lower and the subject becomes more sensitive to low levels of light
photopic vision
“day vision” the visual process used when background light is high
high acuity, good color vision, lack of sensitivity to low levels of light
scoptopic vision
the visual process when the background light is low
poor acuity, little to no color vision, high sensitivity
central scotoma
blind spot in the center of the visual field
Trichromatic Theory
three different types of cones in the retina each has a different pigment and therefore detects a different primary color
true at the level of receptor cells such that there are 3 different types of cones with 3 different patter of color sensitivity
Process Theory of Color
two opponent processes exist at the ganglion cell level
red vs green
blue vs yellow
proved by color blindness
negative afterimage effect
when an intense colored image is taken away a person sees a momentary flash of the opposite or complimentary color
