2.Sensation and Perception Flashcards
what is Sensation
sensation is the process by which our sense organs and receptors detect and respond to physical stimuli that stimulates them.
is sensation passive or active
sensation is an automatic PASSIVE process
what is perception
perception is the process of assigning meaning to raw information
is perception passive or active
perception is an active process
Identify the key processes of sensation and perception
reception and receptive fields
transduction
transmission
interpretation
(RTTI)
describe the reception and receptive fields process
sensory receptors receive and process sensory information
describe transduction process
receptors change the energy of sensory information into a form that can travel along neurones as action potentials
describe transmission process
sensory information is sent to the relevant area of the brain via the thalamus
describe interpretation process
sensory information is given meaning. Existing knowledge from memories are used to make sense of the raw sensory information
Describe visual sensation.
the detection or awareness of the presence of light energy produced by stimulation of visual receptors in the eye
Describe Visual perception
the selection, organisation and interpretation of visual sensations by the brain into meaningful objects and events
function of cornea
-light enters eye via cornea
-protect the eye and helps focus light rays onto the retina
function of aqueous humour
-watery fluid
-helps maintain shape of eyeball
-provides nutrients and oxygen to they eye
function of pupil
-black circle in centre of eye
-helps control amount of light that enters they eye
function of the iris
-coloured part of eye
-contains muscles that controls the size of the pupil
function of the lens
-focuses light onto the retina
function of the vitreous humour
-helps maintain shape of eyeball and focus light
function of the retina
receives and absorbs light and processes images
what does the image focused on the retina look like
upside down (inverted) and back to front (reversed)
what is the order of light through the eye
cornea
aqueous humour
pupil
iris
lens
vitreous humour
retina
optic nerve
how many rods
120 mil
how many cones
6 mil
function of rods
-respond to very low levels of light
-responsible for night vision and peripheral vision
-sensitive to movement
function of cones
-respond to high levels of light
-detect fine detail and are involved in colour vision
transduction process for vision
-when photoreceptors detect light energy, they convert this information to a type of energy that can be sent to the brain for further processing
-these signals are sent to ganglion cells that generate acton potentials
optic nerve function
transmits visual information from retina to primary visual cortex
what is the optic chiasm
-point where axons cross
-contralaterally organised
what are visual perception principles
visual perception principles are ‘rules’ that we apply to visual information to assist our organisation and interpretation of the information in a consistent and meaningful way
what are gestalt principles
refers to how we organise the features of a visual scene by grouping them to perceive a whole, complete form
- ‘the whole is greater than the sum of its parts’
identify the gestalt principles
figure ground organisation
closure
similarity
proximity
what is figure ground organisation
we organise visual information by perceptually diving a visual scene into a figure, which stands out from the (back)ground
-figure and ground are separated by the CONTOUR
name the subdivisions of figure ground organisation
reversibility and camouflage
what is reversibility
when the figure and ground are ambiguous, our perception is dependent on which aspect of the visual scene we label as the figure
what is camouflage
when the figure and ground are not easily separated, but instead blend together
what is closure
closure is the perceptual tendency to mentally ‘close up’, fill in or ignore gaps in a visual image. This is so we can perceive the objects as complete or whole
what is similarity
similarity is the perceptual tendency to perceive parts of a visual image that have similar features and group these according to size, shape, colour or texture-perceiving them as whole
what is proximity
proximity is the perceptual tendency to perceive parts of a visual image which are positioned close together as a ‘whole’
what is depth perception
the ability to accurately estimate the distance of objects and therefore perceive the world in three dimensions
-done through use of depth cues