perception Flashcards
perception
the experiences resulting from stimulation of the senses
principles of perception
changes based on added info
involves processes like reasoning + problem solving (uses rules)
occurs with action
is limited, selective, involves memory + time
largely automatic
viewpoint invariance
ability to recognize an object seen from different viewpoints (computers lack this)
bottom-up processing
stimulus driven
lowest to highest level (image on retina to visual cortex)
gathers data from our surroundings
ex// burning your hand on the stove
feature-dector theories
bottom-up processing
objects are initially seen as sets of basic features + perception works by combining features into coherent objects
ex// kittens raised w/o exposure to horizontal lines were later blind to them, frogs have feature detectors for edges, contrast, and shadows
problems with bottom-up
sheer volume of info would be overwhelming or impossible to process
top-down processing
goals/knowledge driven
Originates at the highest level (knowledge of the environment leads to expectations which focuses attention to specific stimuli)
ex// speech segmentation (native vs non speaker)
Bottom-up → same sound stimuli for both listeners
Top-down → different perceptions of the sound stimuli for listeners based on knowledge
ex// PLACEBO EFFECT
Helmholtz’s theory of unconscious inference
(TD)
Image on retina is ambiguous
Likelihood principle = perceive the object that is most likely to have caused the pattern of stimuli we’ve received
Solve by applying knowledge, like problem solving (Unconscious process)
Gestalt perceptual organization
BU
minimize the role of experience in perception
ex// good continuation, simplicity, similarity
Environmental regularities
TD
Regularly occurring physical properties -
Oblique effect = perceive horizontals and verticals more easily than other orientations (buildings, trees, plants)
Light-from-above assumption = assume light comes from above (sun, artificial light)
semantic regularities
TD
Characteristics associated with the function carried out in different types of scenes; meaning
Use of regularities are often unconscious
Scene schema = knowledge of what a given scene contains
bayesian inference
TD
Probability of an outcome is determined by -
Prior probability = our initial belief about the probability of an outcome
Likelihood = extent to which available evidence is consistent with the prior probability
Start with experience, knowledge → update with additional information
experience-dependent plasticity
brain is changed by exposure to environment so it can perceive more efficiently
