sensation and perception Flashcards
define sensation
Initial detection and processing of stimuli
define perception
Organising and interpretating what sense organs take in
what is the cornea?
- Transparent covering
- Protects the eye
- Helps focus the light rays onto the retina
what is the pupil?
- A small adjustable opening
- Black circle in middle of the eye
- Dark conditions = expands to let more light in
- Light conditions = contracts to reduce light let in
what is the pupil?
- A small adjustable opening
- Black circle in middle of the eye
- Dark conditions = expands to let more light in
- Light conditions = contracts to reduce light let in
what is the iris?
- Control expansion and contraction
- Coloured muscle
what is the lens?
- Focuses light into the retina
- Held by ring of ligaments attached to ciliary muscles
what are the cilary muscles?
- Holds lens
- Change the shape of the lens and focal length
- Allows us to see objects clearly close up and at a distance
what is the retina?
- Sensitive surface
- Back of eye
- Contains photoreceptors & neurons = specialised to detect and respond to different features of light
what parts of the eye are within the retina?
- Rods = responds to low levels of light and used for night vision
- Cones = respond to higher levels of light and enable us to see in the bright light used for day vision
what is the fovea?
- Back of eye
- Cones are plentiful
- Clearest vision
what is the vitreous humour?
- Helps maintain shape of eyeball
- Helps focusing
what are the 3 steps of sensation?
- reception
- transduction
- transmission
what is the first step of sensation?
Reception
- Presence of physical stimuli such as sound waves and light
- Detected by sensory neurons in our sense organs
what is the second step sensation?
Transduction
- Different forms of stimuli are converted into electrochemical energy = energy that human brain can process
what is the third step sensation?
Transmission
- Energy is transferred to brain for processing
what are the 3 steps in perception?
- selection
- organisation
- interpretation
what is the first step of perception?
Selection
- Brain filters the stimuli
- Selecting importing features for further processing
- Ignoring unimportant features that receive no further processing
what is the second step of perception?
Organisation
- Grouping the selected features of stimuli to form a whole
- Referred to as Gestalt
what is the third step of perception?
Interpretation
- Brain interprets the image
- Gives it meaning
- Our understanding of the visual
what did gestalt believe?
- We rely on four main types of principles to organise separate stimuli into meaningful patterns
what are gestalts 4 perceptions?
- figure ground
- proximity
- similarity
- closure
what is figure ground?
- Viewer uses an imaginary contour line to divide features of the stimulus into an object and background
what is proximity?
- Stimuli that are close together in space are perceived as belonging together
what is similarity?
- Stimuli that are similar in some way such as having the same shape or colour are perceived as grouped together
what is closure?
- Gaps in objects are closed so they are perceived as a recognisable whole shape
