Chapter 5: Sensation & Perception Flashcards
bottom-up processing
stimuli –> nerve impulse –> brain regions
strabismus
no natural coordination of eyes
binocular cues
retinal disparity between eyes, closer objects require convergence from muscles
gestalt principles
humans are hardwired to create meaning out of sensation
perception
recognition+identification of a sensory stimulus, inferring meaning
top-down processing
perception processes led by cognitive processes
hemi-neglect
ignore completely one side of visual field
due to damage of where pathway
what pathway (ventral stream)
occipital to temporal cortex
place theory
different frequencies activate different regions on basilar membrane
prosopagnosia
inability to identify and remember faces
association areas
links sensory info with language comprehension
figure-ground
objects either are perceived in the background or foreground
ageusia
inability to taste, head trauma
proximity
visual stimuli near one another tend to be grouped
shading
gradations of darkness on the surface of a real object or on a depiction of an object, providing a depth cue.
gate control theory of pain
patterns of neural activity create gain preventing message from reaching areas where they’d be perceived as pain
where pathway (dorsal stream)
occipital to parietal lobe
visual agnosia
damage to what pathway, describe objects but not identify them, can not discriminate b/w similar things
trichromatic theory
3 different sensors for each colour corresponding to different wavelengths
closure
tend to fill in small gaps in objects
sensory adaptation
repeated exposure to same stimuli brings decreased response
tonotopic map
information from specific parts of cochlea mapped to specific parts of cortex
amblyopia
untreated strabismus which results in blindness in one eye
opponent process theory
colour pairs work to inhibit one another
perceptual constancies
top-down tendency to view objects as unchanging despite shifts in stimuli
familiar size
assume similar objects=similar size
cingulotomy
destruction of cingulate cortex, help with chronic pain
elevation
higher an object is in the visual plane is seen as further away
ataxia
impaired coordination
sensation
act of using sensory systems to detect environmental stimuli and transmission of this info to brain
visual angle
object size/distance, the further the object the less it subtends the retina
ansomia
inability to smell
similarity
stimuli resembling one another tend to be grouped
relative size
if 2 objects same size, one seems smaller if it is farther away
familial dysautonomia
inability to detect pain/temp, can regain
cones
6 millon, cover entire fovea area, colour, sharpness
phantom limb sensation
sensations/hallucinations coming from amputated limbs
good form
stimuli forming a shape tend to be grouped
Touch (organs)
free nerve endings, meissner’s corpuscles, Merkel’s discs, Ruffini’s end, pacinian corpuscles
texture gradient
we see more detail when things are close
frequency theory
different frequencies converted to different rates of action potential in ear
rods
100 million, highly sensitive to light, night vision
sensory transduction
converting stimuli into neural impulses
absolute threshold
minimal stimulus necessary for detection
difference threshold
smallest difference b/w stimuli we can detect
linear perspective
parallel seem to converge in the distance
interposition
an object blocked by another is seen as further away
continuity
stimuli along same plane tend to be grouped
size constancy
refers to our assumption that
size is a constant and that if an object changes its visual angle on the retina, it is the distance
that changed, not the size of the object
Size illusions
where when the visual angle is
the same on both lines, but the distance cues convince us that one is closer and the other is
farther –> the further one must be bigger
