Sensation and Perception Flashcards
sensation
bringing “raw input” into the brain from sensory organs
transduction = translation
the process by which a sensation can be translated into an understandable neural signal or message
sensory adaptation
tendency to pay less attention to a non-changing source of stimulation
bottom-up processing
- automatic intro coming in
- taking sensory information and then assembling it and integrating it
difference threshold
smallest detectable difference between two stimuli that can be detected at least 50% of the time
weber’s law
the stronger the baseline stimulus, the bigger the change needed to notice a difference
signal detection
the analysis of sensory and decision making process in the detection of faint, uncertain stimuli
signal detection theory
alls us to measure how much perceptual decisions are made under conditions of uncertainty
iris
muscle that controls the pupil
rods
- sensitive to light and excel in dim lighting
- does not perceive color
cones
- perceive color
- operate under normal daylight conditions
- allow us to focus on fine detail
fovea
- area of retina where vision is the clearest
- contains only cones, no rods
opponent process theory
we have different color channels in which activations goes from one color and then the other color in the pair inhibits the other
gestalt principles of perceptual organization
rules that govern how we perceive objects as wholes
continuity
we perceive points forming a smooth line as belonging to the same group
linear perspective
parallel lines converge at the horizon
relative size
we can gauge the size of the object even if it is far away because we know the “actual” size of the object
retinal disparity
- binocular cue for perceiving depth by comparing images from the retinas in the two eyes
- closing one eye and watch the difference between where your finger is
perception
how the brain interprets sensory information
absolute threshold
smallest amount of stimulus that can be determined at least 50% of the time
lens
adjusts the shape of the pupil to focus object in the retina
monocular depth cues
use of only one eye
binocular depth cues
requires both eyes
trichromatic theory
- three types of cones that pick up the different wavelengths of color
- short (blue)
- medium (green)
- long (red)
attention
a narrow focus of awareness
top-down processing
recalling old information to interpret sensory information
psychophysics
study of relationships between physical qualities of stimuli and the subjective responses they produce
cornea
- bends light to begin forming an image on the retina
- where light first enters the eye
pupil
opening to allow light into the eye
photoreceptors
specialized neurons found in the retina that convert light into electrical signals that stimulate physiological processes
optic nerve
bundle of axons at the back of the eye carrying visual info to the brain
color deficiency
- when someone is missing a certain kind of cone
- color blindness
proximity
close objects belong together
closure
our brain can process and understand an image even if there are gaps in it
similarity
similar stimuli are grouped together
figure ground
identify the main object of a scene (the figure), which stands out from the background
depth perception
the ability to use two-dimensional image projected on the retina to perceive three dimensions
texture
closer objects appear to have more texture
shading/highlights
usually used for curved surfaces
occlusion
distant objects are blocked by closer objects
nearsightedness
elongated eyeballs interfere with vision for father objects
farsightedness
shortened eyeballs interfere with vision for close objects
