CP. 3

sensation

nervous system obtains data from the environment

perception

brain comprehends sensation

sensory systems that lead to perception

• touch

• taste

• balance

• smell

• bodily awareness

touch…aka

somatosensation

taste…aka

gustation

smell…aka

olfaction

balance…aka

vestibular

bodily awarness…aka

proprioception

perception: more than seeing & hearing?

ability to take action in responce to the environment

Summer project myth (1966 MIT)

thought they could solve problem w/ computer vision

cumputer progress in 50’s-60’s

edge detection & letter recognition

computer progress 80’s

object recognition (3D&2D images)

computer progress 90’s-present

machine learning (identify objects regardless of viewpoint, size, lighting)

Machine learning

alg. that learn from data and make predictions w/o instructions

deep learning

programs that mimic human pattern recognition

Knowlegde gap

• make mistakes w/ images that a human wouldnt

• ai cant make context of scenes(air show)

inverse proection problem

determine object based on shape on the retina

Images cast onto the retina is _____ and is not processed ______ by the ______ system

ambiguous

automatically

visual

single retinal image can be processed _____ times

infinite

eg. can be tilted or bigger at a distance

ai vs human for inverse projection

human

occulusion def.

part of an object that is blurred

view point invariance

recognize object regardless of view

how do computers achieve viewpoint-invariance

complex math calculations

environmental energy

physical stimuli that activates our sensory receptors

observer knowledge

pre-existing knowledge on a situation

bottom-up processing

image>retina>electrical signal>visual receiver in the brain

top-down processing

starts in the brain

eg. identify an object

blob

same blob can be different object based on the context

(top down)

8 month old language (Saffran Experiment 1996)

they can learn stat language (pretty baby)

Saffran Experiment findings

• babies listened longer to part word stimuli(syllables that dont go together)

• segmented the string into words

Hermann Von Helmholtz

made the ophthalmoscope (blood vessel in eye)

found that images in eye are ambiguous

unconscous inference

perceptionms are result of unconscous assumtions about the environment

gestalt psychologists

proposed principles governing perception, such as laws of organization, and a perceptual approach to problem-solving involving restructuring

(how we percieve objects)

gestalt psychologists rejected which idea

perceptions were formed by adding up sensations

stroboscope (Max Weirtheimer) name for this…

illusion of movement w/ fast moving pictures

apparent movement

3 componets make up apperant movement

one light flash one and off

period of darkness (fraction of a second)

second light flashes on and off

principles of perceptual organization. created by…

how the brain simplifies complex visual scenes by grouping elements into meaningful wholes rather than separate parts (gesalt psychologoist)

principle of good connection

straight or curly lines belong together

law of pragnaz;principle of good figure;principle fo simplicity

pattern percieved as simple as possible

principle of simularity

simular things are ggrouped together

regularities in the environment

charactistics of the environment that frequently occur

physical regularities

regular occuring physical properties of an environment

eg. vertical lines

oblique effect

easily percieve horizontal and vertical lines

muller-lyer illusion

flight line question

scene schema

specific things associated w/ specific scenes

eg. bread and kitchen

perceptual speed

identify objects faster when fit the scene

semantic regularities

some actions belong in certain areas

bayesian inference (named after?)

initial belief about outcome beofre seeing evidence and the liklihood (current evidence is specific w/ outcome (thomas bayes)

overcome oblique effect?

bayesian inference network

Experience-Dependent Plasticity

brain is shaped by environmental regularities

Greeble expirment

participants were better abled to recognize ai generated faces

brain ablation

study of effect after removing part of the brin

neuropsychology

study people w/ brain damage aand observe behavior

object discrimination task

chose same object after delay

landmark discrimination task

remmeber location and choose it after delay

dorsal (pathway)

top of organism (back if brain to top of brain; where things are)

Ventral pathway

side to bottom of the brain(what an object is)

Patient D.F (1955)

temporal lobe damage from carbon monoxide poisoning

couldnt rotate card to fit slot

could roate after starting the action of moving the card

purpose:

• 2 sep. areas for judging orientation and cordinating action

steps of picking up cup of coffee

perception-what pathway (identify cup)

action-where pathway (reach for cup)

action&perception pathway (position to pick up&perception of cups handle

action&perception pathway (lift w/ right force&how full cup it)

Size weight illusion

large=heavier>if light=feels lighter than what it actaully is

viewpoint-invariance

recongize object from dif. point of view

Assumption 1&2&3

1. surface same color(even w/ shadow)

2. light comes from above

3. color same even in dif. lighting

texture gradient

closer object= more detail

linear perspective

lines converge at horizon

retinal display

further away=less dif. between each eye

closure

complete images

action pathway

occipital lobe to the parietal lobe associated with neural processing that occurs when people take action. It corresponds to the where pathway

blindsight

cant see; but can in the brain

convergace

see something close=eyes converge

Direct pathway model

model of pain perception that proposes that pain signals are sent directly from receptors to the brain

Dorsal (where) pathway

visual cortex in the occipital lobe to the parietal lobe.

familar size

knowledge of typical size for an object

Law of Pragnanz

every stimulus pattern is seen to make the resulting structure as simple as possible

Landmark discrimination problem

remember an object’s location and to choose that location after a delay. Associated with research on the where processing stream.

Likelihood

Bayesian inference, the extent to which the available evidence is consistent with the outcome

liklihood principle

unconsciously interprets ambiguous sensory information as the most probable real-world object

Object discrimination problem

remmeber object and pick it after delay

Optic ataxia

cant reach amrs towards object

Pareidolia

faces in objects

Perception pathway

occipital lobe to the temporal lobe associated with perceiving or recognizing objects. Corresponds to the what pathway.

Perkin’s Laws

conjunctions of lines corresponds to

different shape and orientations of objects

Principles of perceptual organization

small elements of a scene or a display become perceptually grouped to

form larger units.

Retinal Disparity

dif between right and left eye

Semantic regularities

Characteristics associated with the functions carried out in different types of scenes

statistical learning

learning about transitional probabilities and other characteristics of language

Stereopsis

perception of depth produced by the reception in the brain of visual

stimuli from both eyes

Thatcher illusion

upside down face

landmark task

damage to paritel made it hard

object task

damage to temporal made it hard