perception Flashcards
what is perception?
experience resulting from stimulation of the senses
changes based on added information
an active process
occurs in conjunction with actions
perceptual system uses two types of information
- environment energy stimulating receptors
- knowledge and expectations
perceptual objects
interpretation and reproduction of the distal object rather than a reflection
why can’t computers replicate human perception?
inverse projection problem
- can’t see 3D
- different object can have same reflection on retina, hard for computers to determine object responsible for image
objects can be hidden or blurred
- computers see contrast between pixels and cannot interpolate missing parts
- people can identify blurred or obscured objects
viewpoint invariance
- objects look different from different angles
- computers have limited ability to recognise them as same object
approaches to understanding perception
direct perception theory
constructive perception theories
direct perception theory
bottom up processing
perception comes from stimuli in environment, starts from senses
parts identified and put together then recognised
constructive perception theories
top down processing
processing originates in brain - top of perceptual system
people actively construct perceptions using information based on expectations
heavily influence by knowledge, experiences and expectations
bottom up processing
sequence of events from stimulation of receptors in the eye to brain through nervous system
top down processing
perception involving knowledge of the environment, expectations and attention to specific stimuli
object perception
Helmholtz theory of unconscious inference
Gestalt principles of organisation
moder view on perception
- Helmholtz’s theory of unconscious inference
top down theory to address visual ambiguity
some perception due to unconscious assumptions,ptions we make about the environment
- use own knowledge to inform perception
- infer much of what we know
- likelihood principle
perceive the world in the way that is most likely
judgement of what is most likely based on unconscious inference (assumptions)
based on past experience
- Gestalt principles of organisation
historic view = perception involves adding up senses
new theory = Gestalt, used o explain way elements are grouped together to create larger objects
mid groups patterns according to intrinsic laws based on knowledge about the world
- perception determined by specific organising principles
- bottom up
- role of experience minor compared to innate principles
- The principles
figure ground principle
- needs to be distinction between and object and its background
principle of good continuation
- helps us perceive smooth lines
- when points connected, seen in a way which results in smoothest path
- overlapping objects seen as continuing behind overlapping
law of pragnanz
- principle of simplicity or good figure
- every pattern seen as simplest structure possible
principle of similarity
- similar things appear grouped together
eg by shape or colour
- modern view of perception - regularities
perception influenced by common physical properties of the environment that occur frequently and therefore expect to see
based on experience, not innate
- regularities of the environment
characteristics of the environment that occur frequently and therefore influence what we expect to see
physical
semantic
scene schema
