345 - Chapter 3

sensation

how our nervous system receives stimulus energies from the environment

perception

conscious experiences resulting from the stimulation of the senses

characteristics of perception

- change based on added information

- similar to reasoning

- occur in conjunction with actions

the image on the retina is...

ambiguous

_________ is a problem for computer vision

occlusion (blurry images or partially hidden objects)

viewpoint invariance

Objects look different from different viewpoints; a labor-intensive process for a computer

bottom up processing

none/minimal previous knowledge; sequence of events from eye to brain or from the sensory organs to the brain

top down processing

knowledge and expectations influence the interpretation of situation

transitional probabilities

the likelihood that one sound/word will follow another; learned as we learn speech

transitional probabilities are a type of _________

statistical learning

Helmholtz's theory of unconscious inference

Perceptions result from unconscious assumptions or inferences that we make about the environment

likelihood principle

Helmholtz; we perceive the object most likely to have caused s stimulus pattern; aka the brain's 'best guess'

what idea did gestalt psychologists reject?

rejected structuralism

what did the Gestalt Principles propose?

perceptual organization involves rules for grouping small elements of a scene

apparent motion

Max wertheimer; perception of movement due to stimuli in different locations flashing one after the other with proper timing

principle of good continuation

lines tend to be seen as following the smoothest path

principle of the importance of simplicity

AKA Law of Pragnanz or good figure integrity; stimulus patterns are interpreted to make the structure as simple as possible

principle of similarity

similar things are perceived as grouped

regularities of the environment (included in slides)

oblique effect, light from above assumption, semantic regularities

oblique effect

verticals and horizontals are more easily perceived than other orientations

semantic regularities

meaning of a scene is often related to what happens within the scene/ what is found within the scene (scene schemas)

Bayesian inference

computational approach to perception that uses 2 factors to estimate the probability of an outcome (prior probability and likelihood of a given outcome)

approaches that incorporate top-down processing

unconscious inference, environmental regularities, and Bayesian inference

approaches that incorporate bottom-up processing

gestalt principles

what stream

processing stream in the brain that determines the identity of objects and is also called the ventral pathway; it corresponds to the perception pathway

where pathway

processing stream in the brain responsible for determining the location of an object; called dorsal pathway and corresponds with the why pathway and action pathway

mirror neurons

neurons that respond to an action while a subject watches it being performed in the same way as if they were acting; existence supported by fMRI research