Sensation and Perception - 1 Flashcards
Weber’s law
the “just noticeable difference” or “difference threshold” is a constant proportion of the original stimulus size
signal detection theory
detection depends on experience, expectations, alertness, etc.
(more likely to notice a door slam outside when waiting on the pizza guy)
sensory adaptation
diminished sensitivity as a result of constant stimulation (“can you feel your underwear”)
sensory habituation
diminished sensitivity due to regular exposure (do you notice the train?)
perceptual set
tendency to see something as part of a group – speeds up signal processing
inattentional blindness
failure to notice something added because you’re so focused on another task (gorilla video)
change blindness
failure to notice a change in the scene (door study – people did not notice when the person they were talking to was replaced with another person)
cocktail party effect
notice your name across the room when its spoken, when you weren’t previously paying attention
cornea
protects the eye
pupil/iris
controls the amount of light entering the eye
lens
focuses light on the retina
retina
contains rods and cones
fovea
area of best vision (cones here)
rods
black/white, dim light
cones
color, bright light (red, green, blue)
bipolar cells
connects rods/cones and ganglion cells
ganglion cells
opponent-processing occurs here
(the human visual system interprets information about color by processing signals from photoreceptor cells in an antagonistic manner)
blind spot
occurs where the optic nerve leaves the eye
feature detectors
specialized cells that see motion, shapes, lines, etc.
located in occipital lobe (experiments by Hubel & Wiesel)
trichromatic
three cones for receiving color (blue, red, green)
explains color blindness – they are missing a cone
opponent process
complementary colors are processed in the ganglion cells – explains why we see an after image
negative afterimage
when you can no longer see the stimulus, you see its complementary color (seeing green after seeing a red apple)
positive afterimage
when you can no longer see the stimulus, you see the color that it really is (seeing red after seeing a red apple)
visual capture
visual system overwhelms all others (nauseous in an IMAX theater – vision trumps vestibular system)
