sac 1 (visual) Flashcards
sensation
The process by which our sense organs and receptors detect and respond to a sensory stimulus (raw sensory data which is sent to the brain).
perception
the process where we process and give meaning or understanding to sensory information.
distinguish sensation and perception
Distinguished for the purpose of studying, however there is no clear boundary between the two
6 stages of sensation and perception
Reception Transduction Transmission Selection Organisation Interpretation
reception
the detection and response to sensory information on the body
transduction
process by which energy from the sensory information is converted into a form electro chemical energy that can travel along neural pathways.
transmission
process of sending sensory data to the relevant areas of the brain via the thalamus.
selection
acts like a filter of sensory information enabling selection of only what is relevant.
organisation
regrouping together the individual components of sensory information that we have selected and recognises the image so that we are presented with meaningful information.
interpretation
sensory information is given meaning
photoreceptor and their purposes
Rods - used for conditions with low light, only registers black and white
Cones - used for conditions with highlight, can see all visible colours
The eye
iris pupil lens cornea retina optic nerve ciliary muscle blind spot aqueous humor vitreous humor
Gestalt Principles, list 4
describes ways that we organise parts of a visual scene by grouping them to interpret a whole, complete image and make sense of it. figure ground closure similarity proximity
figure ground
organises visual information by dividing what we see into a ‘figure’ which stands out from the background
(camouflage is when the figure and the background are not easily separated)
closure
the tendency to mentally close the gaps in an image in order to perceive objects as a whole
similarity
the habit we have of perceiving parts of a visual image that have similar features as belonging together as a group
proximity
perceiving parts of an image which are positioned close together as belonging in a group. we group things based on how close they are to each other
visual perception principles
gestalt principles
depth cues
perceptual constancies
they help us organise and make sense of visual information.
pupil
an opening in the iris that controls the amount of light let into the eye
lens
focuses light onto the retina, also changes its shape depending on how far away something is so you can still see it clearly
cornea
convex shaped covering that protects the eye and helps focus light rays onto the retina
retina
receives and absorbs light, image is focused onto retina and inverted
optic nerve
carries image to the brain
list pictorial depth cues
linear perspective - parallel lines coming together
interposition - overlap, things in front are closer
texture gradient - more detail close up
relative size - bigger closer, smaller further away
height in the visual field - closer to horizon further away
perceptual constancies
how we perceive an object as remaining stable an unchanging despite any changes in the location of the retina.
size constancy
shape constancy
brightness constancy
perceptual set + list
the influence of our expectations on the interpretation of visual images
- past experience
- context
- motivation
- emotional state
- cultural back ground
past experience can set us up to..
see something depending on our individual life experiences
context
the setting or environment you are in when you perceive something and how our visual perception of something can change depending on this
motivation
internal processes cause behaviours directed toward achieving a particular goal. often we can see what we want to see.
emotional state
different emotions can set us up to see things consistently with the emotions we are feeling.
cultural background
can set us up to perceive things in ways different from people from other cultures
ciliary muscle
moves the lens and changes shape of it, bulges to focus on close objects and flattens to focus on things far away
binocular depth cues
two eyes working together
convergence - when our eyes turn inwards to focus on something that is very close
retinal disparity - is how because our eyes are far apart we take in two separate images and our brain compares and combines these images
depth perception
how we can estimate the distance of objects and therefore see the world in 3d by using cues in the environment
monocular depth cues
one eye
accommodation - the automatic adjustment of the shape of the lens to focus on an object depending on its distance.
pictorial cues - used by artists to create depth in 2d images
perceptual distortion
inconsistency or mismatch between interpretation and reality
visual illusions
c1onsistant misinterpretation of real sensory information. every time we look at the same sensory information we experience the same misinterpretation
muller lyer illusion
biological explanation
thought to be different types of eye movement but since proven incorrect
psychological explanation
past experience, misinterpret the illusion based on familiarity with 3d objects, square buildings
social explanation
culture, environment, past experience. people who don’t live in square shaped buildings mightn’t fall for the illusion
Ames room
manipulates our depth cues, monocular depth cues only, distorts size constancy
synaesthesia
perceptual experience where stimulation of
one sense produces additional unusual experiences in another. changes perceptual experience of the sense
vitreous humour
clear gel that fills space between the lens and the retina. keeps eyes shape, allows light to pass through
aqueous humour
fluid produced by the eye that provides nutrition and protects the eyes
lobe of the brain where visual information is processed
occipital lobe
