Theories of perception Flashcards
Rene Descartes
- only thing we can be sure about is what we are thinking
- Alternative view: Naive realism
Neisser
- Naive realist
- 3 beliefs about visual perception:
1) visual experiences mirror eternal stimulus - challenge = hallucinations
2) visual experience starts + ends with onset + offset of external stimulus - challenge = visual persistence, visual memory
3) visual experiences are passive copies of the outside world which could be described using verbal reports
Naive realist - passive, bottom-up process in perception
- Selfridge’s
- Model of visual letter recognition
- The pandemonium model
- first decompose image into different features
-features similar to other letters recognised
-decision on which letter it is - Bottom -up = all info goes in 1 direction
Naive Realist-passive perception
Distal StiMUlus = stimulus in distance
- stimulus generates input + soundwaves from distal stimulus travel to ear
- ear + soundwaves in our ear is proximal stimulus
- perception is a process of decision making + problem solving
Naive Realist- The modularity of mind hypothesis - Fodor
-Bottom-up, passive approach
- Info comes in through senses
- Then we have input modules/special purpose processors/ smart detectors
- interested in different types of info
- info is analysed
- info is sent off to central processors that interpret the stimulus
Gestalt laws of perceptual organisation
- How do we break the world into recognised + distinct objects
-Laws on how we group info
-groping by proximity -> close = grouped
-grouping by similarity -> e-g. colour , shape
-grouping by lines > see things As smooth lines - grouping by common region (Palmer) -> interaction of grouping principles + some dominate (boundaries)
Neisser-Naive Realism
- ideas of experience based on passive copies is incorrect
- Gestalt principles contradict- sensory info organised by coding principles that sort input into things that might be objects
Quinn, Burke + Rush- Infant object study
- 3 month old- not much experience with object recognition
- when infants look at things they’ve already seen don’t fixate
-If shout new object fixate on it - grouping known vs unknown objects
Old look us New Look
- Gestalt referred to as ‘Old Look school of perception > interested in passive coding, bottom -up, stimulus- driven
-New Look > Bruner, Top- down, knowledge driven
Bruner + Postman-card study
- cards briefly presented
-Normal cards more accurately recognised than incongrous cards (altered suit/ colours) - knowledge of world influences perception of stimulus
-effect of expectation on perception
knowledge/ familiarity- Selfridge’s Model
-present single letters briefly than masked (cuts Short processing of letter)
-ppts say what they see
-common letters better reported than rare ones
Epstein + Rock- interpretation + experiences
-How we interpret figure depends on what we’ve experienced previously (recency) or what we expect to happen next (pattern)
-seemed to be driver by recency
Minksy’s frame theory of perception -role of expectancy
-Based on knowledge of world we actively generate expectations about what will occur next
- Theories present in vision + audition
-e-g-enter new lecture hall + have expectations about what in the room
-actively compare expectation to reality
Bruner’s perceptual readiness theory
- Need +value determine perceptions
-perceptions reflect how we construct world - Task: alter size of spot light so it matches comparison disk
-generally good estimates when disk is neutral but changes dramatically when replaced with coins
-overestimated size of coins + this increased with value of coin
-poor children estimates more extreme than rich
simplicity VS Likelihood-Hochberg
- Minimal principle -> perceive most simply or economically fit the sensory pattern
- Likelihood principle -> perceive object- that would most likely fit pattern under normal circumstances
- Minimal occurs more
- However not all time -assumption light for comes from above is no simpler than light coming from below
Peterson + Hochberg- Necker cube
- interpretation of figures depends on where ppt fixates
- where we look on stimulus influences our perception of it
crude to fine distinction (global to local processing)
- global = look at overall image
- local = detail
-when ask ppts about large letter faster at responding because the little letter doesn’t interfere (no interference on global by local processing)
-If small + large letter same = fast response - If small isn’t consistent slower identification
- global-to-local interference
- we have a global preference = reaction time shorter when classifying global
- Extract global info first -quicker to get so have more global info
