chapter 3 terms

algorithm

methodical procedures that are slow, but always get you the right answer

• used by computers, not constructive

• ex: mathematical formula

aperture problem

the brain is looking at the world through a bunch of tiny receptive fields

• the brain can’t tell anything about what’s out there in the visual world

balint’s syndrome

damage from both sides of where/how pathway

• people can’t use visual information to guide their movements

bottom-up processing

• due to changes to the stimulus

• start at the level of the sensory receptor

  • ex: turning up the volume on your phone, perception of sound is louder

computational approach to object recognition

stage theory:

• primal sketch

• 2 ½ D sketch

extrastriate cortex

outside striate cortex

feature integration theory

a stage theory:

• pre-attentive stage

• focused attention stage

focused attention stage

• must consciously search for things in a serial manner

geon

geometrical icons, that no matter the angle we view them, it appears to be the same object

• cylinder, cone

gestalt psychologists

gestalt movement

• the perceptual whole is greater than the sum of its parts

• states that there are many principles by which the brain organizes perceptual information

• focuses on top-down processing

law of good continuation

states that lines are seen as following the smoothest possible path

law of good figure/simplicity

states that we perceive the simplest possible pattern

greeble

humanoid like objects that have families and genders

• in gautier and tarr’s greeble study

heuristic

“best guesses” at solving a problem

• much faster than algorithms, but more error-prone

• do not get correct answer every time

• constructive, used by humans

illusory conjunctions/shapes

kaniza figures

• lines that make up outline of a shape

inverse projection problem

the brain must construct a complete, conscious representation of the world based only on a 2D image on the retina

• the same object can be viewed at many different angles, each of which produces its own retinal image

occlusion problem

one object is partially blocking our view of another

• the brain has to construct a perception of what should be behind the object

pandemonium model of object recognition

a hierarchical model where there are feature demons providing input to cognitive demons which then feed a decision demon which decides what is present by looking at which cognitive demon is most active

• each demon is like a neuron in the brain

law of pragnanz

states that our brain constructs the simplest, most statistically likely perception of all possible alternatives

preattentive stage

• brain unconsciously evaluates all objects in parallel

• immediately processes basic textural information

law of proximity

states that objects that are closer to each other are grouped together

recognition by components theory of object recognition

states that objects can be made up of simple 3D objects called geons

sensations

the individual parts that we perceive

law of similarity

similar things appear grouped together

structuralism

states that what we perceive is merely the sum of its individual parts

template theory of object recognition

a theory that we have a template or complex pattern detector that matches up with a particular letter

top-down processing

• have to do with things the brain already have that are brought to the perceptual situation

  • memory, attention, experience, expectations

    • ex: singing a song and sing different lyrics than your friend, now expect to hear something different

viewpoint dependence

the world changes as the person moves around

viewpoint independence

representation of the visual world that doesn’t change when the observer moves around

• how objects relate to each other in space

viewpoint invariance

not dependent on the angle at which we are viewing the object