CH4 Flashcards
bottom-up processing
process of “sensation”, input of sensory information from the external world is received and sensed as it is
top-down processing
interpretation of incoming information based on our prior knowledge, experiences, and expectations, perception heavily relies on top-down processing
sensation
simple stimulation of sense organ
perception
forming a mental representation
transduction
sense receptors convert physical signals from the environment into neural signals that are sent to the central nervous system
what is the psychological dimension for light waves of LENGTH
hue/colour
sensation → perception from eyes
light waves → retina →rods & cones (photo receptors) →ganglion cells → optic nerve → thalamus → visual cortex
retina
contains sensory receptors that transduce light into neural signals
photoreceptors
rods and cones transduce light waves into signals
bipolar cells
sensory neurons; transfer visual input to ganglion cells
ganglion cells
generates an action potential, sent to the brain by the optic nerve
thalamus
relaying signal to visual cortex
binocular depth cues (binocular disparity)
difference in the retinal images of the 2 eyes that provide information about depth (greater disparity = closer object)
monocular depth cues
information about depth when viewed with only one eye; linear perspective, texture gradient, interposition, relative height, relative size, familiar size
colour blindness
genetic disorder where one (or more) of the cone types is missing causing a colour vision deficiency
synethesia
see words as colours
trichromatic theory
colour vision based on 3 primary colours (red/green/blue → 3 different cone receptors)
what colour & wavelength is the L- cone
red, long
what colour & wavelength is the M- cone
green, medium
what colour & wavelength is the S- cone
blue, short
Opponent process theory
perceive colours in terms of 3 pairs of opposing colours: red vs green, blue vs yellow, white vs black
How do we perceive motion
to sense motion, the visual system must encode information about both space and time (PERCEIVING CHANGE OVER TIME)
dorsal visual stream
travels up from the occipital lobe to the parietal lobes; enables us to identify where an object is and how it is moving; crucial for guiding actions
ventral visual stream
travels from the occipital visual regions into the lower temporal lobe; enables us to identify what we see