S&P test 2

Inverse Projection Problem

An image on the retina can be caused by an infinite number of objects

Viewpoint Invariance

The ability to recognize an object regardless of viewpoint

Perceptual Organization

The process by which elements in a person's visual field become perceptually grouped and segregated to create a perception

Grouping

The process by which elements in a visual scene are "put together" into coherent units or objects

Segregation

 The process of separating one area or object from one another

Gestalt Psychology

"The whole differs from the sum of its parts."

Perception is not built from sensation but is a result from perceptual organization

Apparent Motion

When there is no motion, but it looks like there is due to location of objects

Illusory Contours

Appear real but have physical edge (triangle within Pacman's, perceive that they're forming a triangle)

Principles of Perceptual Organization

 How elements in a scene become grouped together

Principle of Good Continuation

 

Points that, when connected, result in straight or smoothly curving lines are seen as belonging together, and the lines tend to be seen in such a way as to follow the smoothest path

Principle of pragnanz, good figure, simplicity

Every stimulus pattern is seen as simple as possible (think of how you draw Olympic symbols, do it the simplest way)

Principle of Similarity

Similar things appear to be grouped together

Principle of Proximity

Things that are near each other appear to be grouped together (columns of dots, overruled principle of similarity b/c ignored color)

Principle of Common Fate

 

Things are moving in the same direction appear to be grouped together

Principle of Common Region

Elements that are within the same region of space appear to be grouped together

Overpowers the principle of proximity

Principle of Uniform Connectedness

A connected region of the same visual properties, such as lightness, color, texture, or motion, is perceived as a unit

Overpowers the principle of proximity

Figure-Ground Segregation

When we see a separate object, we usually see it as a figure that stands out from its background, or ground

Global Image Features, Degree of Naturalness

Natural (ex: forest): textured zones, undulating contours

Man-made (ex: street, buildings): straight lines

Global Image Features, degree of openness

Open (ex: ocean): visible horizon

Limited Openness (ex: forest): no horizon line

Global Image Features, degree of roughness

Smooth (ex: ocean): contains fewer elements

Rough (ex: forest): small, complex elements

Global Image Features, Degree of Expansion

High (ex: railroad tracks): converging lines

Low (ex: side of a buildings): halted/stopped lines

Regularities in the environment, physical regularities

Regularly occurring physical properties of the environment

Ex: more vertical and horizontal orientations in the environment than angular (both natural and man-made)

Regularities in the environment, light-from-above assumption

Assume light is coming from above

Our perception of illuminated shapes is influenced by how they're shaded combined with this assumption

Regularities in the environment, semantic regularities

The characteristics associated with activities that are common in different types of scenes

regularities in the environment, scene schema

Knowledge of what a given scene typically contains

Theory of Unconscious inference

Perception is a result of unconscious, automatic inferences made by the brain based on prior experience

Likelihood Principle

We perceive the object that is most likely to have caused the pattern of stimuli we have received (Occam's Razor, simplest answer is most likely to be true)

Unconscious Inference

Our perceptions are the result of unconscious assumptions or inferences that we make about the environment

Bayesian Inference

Predictions are based off of:

Prior Probability

Likelihood (the extent to which the available evidence is consistent with the outcome)

Predictive Coding

A theory that describes how the brain uses our past experiences, or "priors" to predict what we will perceive

Lateral Occiptial Coding(LOC)

Active when we view any kind of object: animal, face, house, tool, but NOT when we view a texture or an object with the parts scrambled

Active regardless of object size, orientation, position, etc.

Fusiform Face Area(FFA)

Active when we view faces, located in the fusiform gyrus on the underside of the brain

Damage to FFA can cause prosopagnosia (rare condition, no longer able to recognize faces)

Extrastriate Body Area (EBA)

Lateral Occipital Cortex

Activated when looking at parts of bodies, but not by faces or other objects

Parahippocampl Place Area (PPA)

Activated when viewing places (indoors and outdoors)

Helps us perceive space

Attention

The process that results in certain sensory information being selectively processed over other information

Overt Attention

When you move your eyes from one place to another to focus on an object or location (e.g., searching for something, where's waldo, scanning a phone book)

Covert Attention

When you shift attention without moving your eyes (e.g., looking at the person you're talking to but keeping track of someone in your periphery, paying attention to someone but paying attention to something wild happening next to you)

Selective Attention

Participants selectively focus on the message in one ear (attended ear)

Diachotic Listening

Two different stimuli are presented to the left and right ear

Shadowing

 Procedure of repeating the words as they are heard

Cocktail Party Effect

Ability to focus on one stimulus while filtering out other stimuli

Spatial Attention

Attention to a specific locations in space

Illusory Conjunction  

 Features that should be associated with an object became incorrectly associated with another

Feature Integration Theory

Preattentive Stage: Features of an object are separated

Focused Attention: Features are bound into coherent position

 

Fixations & Saccades

Track eye movements, we find that we tend to scan and pause on points of interest, may fixate on yellow points but we scan and move from each of the point

Visual Salience

Areas of stimuli that attract attention due to their properties

Attentional Capture

Stimulus salience causes an involuntary shift in attention

Saliency Maps

 

Reveals which regions are visually different from the rest of the scene

Scene Schema

An observer's knowledge about what is contained in typical scenes (pot on stove instead of radio on stove)

Just in time strategy

Think of making a peanut butter sandwich and moving your attention as you make it

Inattentional Blindness

Unaware of clearly visible stimuli if they aren't directing their attention to them

Change Detection

Difficulty in detecting changes

Continuity Error

Changes in film, in one scene a women is eating a croissant and then a pancake, harry switches sides at a table in great hall

Spatial Neglect

Damage to the right parietal lobe

Burgess had a stroke, became unaware of sounds, people, and objects that we in the left side of his visual field 

Ecological Approach to Perception

Felt that the traditional laboratory setup to study perception was too artificial

Approach to studying perception by putting participants in natural contexts

Optic Flow

appearance of objects as the observer moves past them

Gradient Flow

difference in flow as a function of distance from the observer

Focus of Expansion

point in difference where there is no flow

Invariant Information

Characteristics that remain constant when the observer is moving

Affordances

Information that indicates how an object can be used

Visual direction strategey

observers keep their body pointed toward a target

Spatial Updating

 Process of keeping track of position within a surrounding environment when moving

Wayfinding

taking a route that involves a lot of turns

Landmarking

objects on the route that serve as cues to indicate where to turn

Cognitive Map

The map in our heads that help us keep track of where we are

Place Cells

Neurons that fire when an animal is in a specific place within the environment (hippocampus)

Place field

The area of the environment within which place cells fire

Grid Cells

Cells in the entorhinal cortex (near the hippocampus) that are arranged in a grid-like pattern

Role of the Parietal Reach Region

Reaching and grasping

Visuomotor grip cells

Neurons that initially respond when monkey sees a specific object and when monkey is forming its hand to grasp the same object

Perception (identifying the object and/or its affordances by seeing) and action (reaching for the object and gripping it with the hand)

Proprioception

The ability to sense body position and movement

Size weight illusion

We predict the larger object will be heavier

adjusting grip

Corollary discharge provides information about the timing and force of the hit

Mirror Neurons

Neurons in the premotor cortex that respond both when a monkey observes someone doing a movement and when the monkey itself does the movement

Audiovisual Mirror Neurons

Responds to action and accompanying sound (in premotor cortex)

Linking sensory perception and action

Detecting things

See baseball being thrown at you, move out of the way to not get hit by it

Perceiving Objects

When car moves can perceive more detail such as this car has one door

Perceiving events

1. Event:

   1. Segment of time at a particular location that is perceived by observers to have a beginning and an end (Each event of ordering coffee bounded by movement)

2. Event Boundary:

   1. Point in time when an event ends, and a new one begins

   2. Often associated with changes in motion (e.g., speed, acceleration)

Social Perception

Film with shapes, people made up a story about the film even though there was no actual plot just based on how the shapes were moving

Point-light walkers

Created by placing small lights on people's joints and then filming the patterns created by these lights when people move

Taking Action

Use motion to help interact with objects

Real Motion

When something moves across our field of view

Illusory Motion

The perception of motion of stimuli that aren't actually moving

Induced Motion

When the motion of one object causes a nearby stationary object to appear to move (Clouds & Moon, movement of clouds makes it seem like the moon is moving too but its stationary)

Motion Aftereffects

When viewing a moving stimulus causes a stationary stimulus to appear to move (Look at waterfall for a minute, then look at rocks and they look like their moving, after you look at moving stimulus then you see movement at stationary item)

Optic Array

Structure created by surfaces, textures, contours

Local Disturbance in the Optic Array

When portions of the optic array become covered and uncovered

Helps us perceive motion (whether our eyes are moving or not)

Block things in your part of optic array

Global Optic flow

The fact that everything moves at once in response to movement of the observer's eyes or body

Signals that the environment is stationary and observer is moving