Quiz 3: Visual Perception Flashcards
Stimuli through sensory organs.
Sensation
Set of processes by which we recognize,
organize, and make sense of the sensations we receive from environmental stimuli; relate to identity and form, pattern, and movement.
Perception
Occurs when this information is used to determine further goals.
Cognition
Who proposed perceptual framework?
James Gibson
Object in the external world.
Distal Object
Carries info to the person.
Informational Medium
Sensory organ receives info.
Proximal Stimulation
Mental image
Perceptual Object
Mental representation of a stimulus that is perceived.
Mental percept/Percept
Receptor cells adapt to constant stimulation by not firing until there is a change in stimulation.
Sensory Adaptation
Gray field replacing stimulus after senses adapt.
Ganzfeld Effect
A clear dome that protects the eye.
Cornea
The opening in the center of the iris.
Pupil
A gel-like substance that makes up the majority of the eye.
Vitreous humor
Where electromagnetic light energy is transduced & converted to neural
electrochemical impulses.
Retina
A small, thin region of the retina, the size of
the head of a pin; where vision is most acute.
Fovea
Convert light energy into electrochemical energy that is transmitted by neurons to the brain.
Photoreceptors
Chemical substances that react to light and transform physical electromagnetic energy into an electrochemical neural impulse that can be understood by the brain.
Photo pigments
Long and thin photoreceptors.
Rods
Short and thick photoreceptors and allow for the perception of color.
Cones
2 fasciculi where info from primary virtual cortex is forwarded to.
Dorsal Pathway (Where)
Ventral Pathway (what)
Ascends to parietal lobe; also called the where pathway and is responsible for processing location and motion information; controls
movements in relation to the objects that have been identified through the what pathway.
Dorsal Pathway
Descends to temporal lobe; called the what pathway because it is mainly responsible for processing the color, shape, and identity of visual stimuli; responsible for the
identification of objects.
Ventral Pathway
What object is & where it is.
WHAT-WHERE HYPOTHESIS
What object is & how it functions.
WHAT-HOW HYPOTHESIS
About where something is located in space; always present in visual information processing.
Spatial information
Describe approaches in which perception starts with the stimuli whose appearance you take in
through your eye; data-driven.
BOTTOM-UP THEORIES
Driven by high-level cognitive processes, existing knowledge, and the prior expectations that influence perception.
TOP-DOWN THEORIES
A theory which states that the information in our sensory receptors, including the sensory context, is all we need to perceive anything; “ecological perception”; sufficient contextual info exists to make perceptual judgement .
Gibson’s theory of direct perception (1979)
Suggest that our minds store myriad sets of templates.
Template theories
Highly detailed models for patterns we might recognize.
Templates
Depth & distance; relative proximity/distance & object parts.
Texture Gradients
Mind stores templates & patterns that we recognize; obtaining chunks of knowledge to long-term storage can later be accessed for fast recognition.
CHUNK-BASED THEORY
We attempt to match features of a pattern to features stored in memory, rather than to match a whole pattern to a template or prototype.
FEATURE-MATCHING THEORY
4 types of demon.
Image Demons
Feature Demons
Cognitive Demons
Decision Demons
In this model, metaphorical “demons” with specific duties receive and analyze the features of a stimulus.
THE PANDEMONIUM THEORY
Feature that give a form its overall shape.
Global Feature
When the letters are close together at the local level, people have problems identifying the local stimuli (small letters) if they are not
concordant with the global stimulus (big letter).
Global Precedence Effect
Constitute the small-scale or detailed aspects
of a given pattern.
Local Feature
When the letters on the local level are relatively far apart from each other, it is harder for
people to identify the global stimulus (big letter) if it is not concordant with the local stimuli (small letters).
Local Precedence Effect
We quickly recognize objects by observing the edges of them and then decomposing the
objects into geons.
Recognition-by-components (RBC) Theory
Who proposed pandemonium theory.
Oliver Selfridge
You can recognize an object even if it is partly obscured by another object.
Viewpoint-invariant
The influences of the surrounding environment on perception.
Context effects
The perceiver builds (constructs) a cognitive understanding (perception) of a stimulus; the concepts of the perceiver and his or her cognitive processes influence what he or she sees.
Constructive/Intelligent perception
Plays an important role in perception; also
emphasizes the role of learning in perception.
Higher-order thinking
The process by which we unconsciously assimilate information from a number of
sources to create a perception.
Unconscious Inference
Objects presented in certain configurations are easier to recognize than the objects presented in isolation, even if the objects in the configurations are more complex than those in isolation.
Configural-superiority effect
A target line that forms a part of a drawing of a 3-D object is identified more accurately than a target that forms a part of a disconnected 2-D pattern.
Object-superiority effect
Indicates that when people are presented with strings of letters, it is easier for them to identify a single letter if the string makes sense and forms a word instead of being just a nonsense sequel of letters.
Word-superiority effect
Individual stores the way the object looks
to him or her.
Viewer-centered perception
Individual stores a representation of the object, independent of its appearance to the viewer.
Object-centered perception
Information is characterized by its relation to a well-known or prominent item.
Landmark-centered perception
Useful for understanding how we perceive groups of objects or even parts of objects to form integral wholes.
Gestalt laws
We tend to perceive any given visual array in a way that most simply organizes the different
elements into a stable and coherent form.
LAW OF PRAGNANZ
What stands out from, versus what recedes into, the background.
Figure-ground
Two different pattern recognition systems, according to Martha Farah.
Feature Analysis System
Configurational System
Specializes in recognizing parts of objects and in assembling those parts into distinctive wholes.
Feature Analysis System
Specializes in recognizing larger configurations, not analyzing parts of objects or the construction of the objects.
Configurational System
This brain area responds intensely when we look at faces but not when we look at other objects.
Fusiform gyrus
According to this theory, the fusiform gyrus is activated when one examines items with which one has visual expertise.
Expert-individuation hypothesis.
Occurs when our perception of an object remains the same even when our proximal sensation of the distal object changes.
PERCEPTUAL CONSTANCY
2 main constancies.
SIZE CONSTANCY
SHAPE CONSTANCY
The perception that an object maintains the
same size despite changes in the size of the
proximal stimulus.
SIZE CONSTANCY
The perception that an object maintains
the same shape despite changes in the
shape of proximal stimulus.
SHAPE CONSTANCY
The distance from a surface, usually using your own body as a reference surface.
Depth
2 depth cues
Monocular depth cues
Binocular depth cues
Can be represented in just two dimensions and observed with just one eye.
Monocular depth cues
Based on the receipt of sensory information in three dimensions from both eyes.
Binocular depth cues
2 kinds of information under the binocular depth cues.
Binocular disparity
Binocular convergence
Your two eyes send increasingly disparate (differing) images to your brain as objects approach you.
Binocular disparity
Your two eyes increasingly turn inward as objects approach you.
Binocular convergence
Neurons that specialize in the perception of depth.
Binocular neurons
Trouble perceiving sensory information.
Agnosia
Kinds of agnosia
SIMULTAGNOSIA
PROSOPAGNOSIA
An individual is unable to pay attention to more than one object at a time.
SIMULTAGNOSIA
Severely impaired ability to recognize human faces.
PROSOPAGNOSIA
An impaired ability to use the visual system to
guide movement; people with this deficit have trouble reaching for things.
Optic Ataxia
Least common, people with this condition have no color vision at all; in this condition the cones are nonfunctional.
Rod monochromacy / achromacy
Only two of the mechanisms for color perception work, and one is malfunctioning; people with this form of color-blindness have difficulty in distinguishing red from green although they may be able to distinguish, for example, dark red from light green.
Dichromacy
The extreme form of red-green color blindness.
Protanopia
Trouble seeing greens with symptoms similar to
protanopia.
Deuteranopia
Confusions of blues and greens, and yellows that disappear or appear as light shades of reds.
Tritanopia
