Sensation and Perception Flashcards
The stimulation of sense organs
Sensation
the selection, organization, and interpretation of sensory input
Perception
Stimulus for the visual system
electromagnetic radiation between 480 and 760 nanometers
Order in which light passes through the eye
cornea>pupil/iris>lens>vitreous humor>retina>ganglion cells>bipolar cells> photoreceptors (rods and cones)
the process by which a stimulus is represented neurally
Transduction
Where does transduction occur in the eye?
Rods and cones
photoreceptor that is scotopic; perceives general form; more numerous; more in the periphery of the retina; more thoroughly adapts to the dark
Rods
Photoreceptor that is photopic; greater visual acuity; less numerous; more in the center of the retina and the only photoreceptor in the fovea; quickly adapts to the dark, but is limited in how much it adapts
Cones
Light enters through this structure in the eye
Cornea
Transparent eye structure that focuses the light rays falling on the retine
Lens
opening in the center of the iris that helps regulate the amount of light passing into the rear chamber of the eye
Pupil
Visual activity is greatest at this spot; only cones
fovea
neural tissue lining the inside back surface of the eye; absorbs light, processes images, and sends visual info to the brain
Retina
the retinal area, when stimulated, affects the firing of that cell
receptive field of a visual cell
Point at which axons from the inside half of each eye cross over and then project to the opposite side of the brain
optic chiasm
neurons that respond selectively to very specific features of more complex stimuli
feature detectors
order by which visual info is processed after transduction
bipolar cells>ganglion cells>optic disk>dorsal lateral geniculate nucleus of the thalamus (if info received by the halves of retina closer to nose; contralateral connection) (if info received by the halves of the retina farthest from the nose; ipsilateral connection)> primary visual cortex> parietal lobe or lower part of temporal lobe
In primary visual cortex; detects orientation of line and location of the line within its receptive field
simple cells
In primary visual cortex; detects orientation of line, movement of line
complex cells
in primary visual cortex; detects orientation of line, length of line
Hypercomplex cells (end-stop cells)
WHAT pathway
Analyzes what the object is; lower part of the temporal lobe
WHERE pathway
analyzes where the object is in relation to the body, in parietal lobe
the human eye has three types of receptors with differing sensitivities to different light wavelengths; short wavelength, medium wavelength, long wavelength
Trichromatic theory
color perception depends on receptors that make antagonistic responses to three pairs of colors
Opponent Process theory
a readiness to perceive a stimulus in a particular way
perceptual set
progression from individual elements to the whole
bottom-up processing
progression from whole to the elements
top-down processing
Things that are near each other seem to belong together
Gestalt proximity
people often group elements to create a sense of closure or completeness
gestalt closure
people tend to group stimuli that are similar
gestalt similarity
people tend to organize forms in the simplest way possible
gestalt simplicity
people’s tendency to follow in whatever direction they’ve been led
gestalt continuity
illusion of movement created by presenting visual stimuli in rapid succession
phi phenomenon
clues about distance based on differing views of the two eyes
binocular depth
an inference about what form could be responsible for a pattern of sensory stimulation
perceptual hypothesis
people tend to divide displas into figure and ground
gestalt figure and ground
Stimulus for the auditory system
sound: compression and decompression of molecules in the air
Order in which sound passes through the ear
outer ear (ear canal)>middle ear (ear drum)>ossicles (hammer, anvil, stirrup)> inner ear (oval window of the cochlea)
fluid-filled coiled tunnel that contains the receptors for hearing
cochlea
different waveform stimulate different areas of the basilar membrane in particular
place theory
what stimulates the basilar membrane area closest to the oval window
higher frequencies
what stimulates the basilar membrane areas farthest away from the oval window
lower frequencies
perception of pitch corresponds to the rate, or frequency, at which the entire basilar membrane vibrates
frequency theory
stimulus for the vestibular system
gravitational pull
stimulus for the gustatory system
molecules dissolved in fluid
primary tastes
sweet, sour, bitter, salty, umami
bumps
papillae
on the perimeter of the tongue
taste buds
where is the primary cortex of gustatory system
insular cortex (in frontal lobe)
stimulus for the olfactory system
molecules in the air
pathway for olfactory system
air>mucous>olfactory dendrites
where does transduction occur in the olfactory system
olfactory dendrites
where is primary cortex of olfactory system
olfactory bulb (temporal lobe)
Only sensory system that does not send signals to the thalamus
olfactory system
stimulus for the somatosensory system
mechanical, thermal, chemical
pathway of the somatosensory system
somatosensory receptors>thalamus>somatosensory cortex (parietal lobe)
slow pain pathway; signals of dull and aching
C fibers
fast pain pathway: signals of sharp pain
A-delta fibers
incoming pain sensations must pass through a “gate” in the spinal cord that can be closed, thus blocking ascending pain signals
gate control theory
