S & P Test 2

image clutter, object variety, and variable views

three aspects of the environment that must be overcome for our ability to detect objects

shape constancy

the concept that an object remains the same shape despite changes to its retinal image

bottom-up processing

the analysis of the smaller features to build up to a complete perception - means that physical stimuli influence how we perceive them

top-down processing

the use of preexisting knowledge to organize individual features into a unified whole - means our existing knowledge of objects influences how we perceive them

memory and perception

two processes integral to understanding object perception

recognition

refers to the ability to match a currently viewed item with an item in memory; the perceptual matching of something currently present to our visual system with a stored representation in memory

representation

refers to the processes that translate stimulus information into a perceptual experience of that stimulus

recognition and representation

two important terms regarding memory and object perception

perceptual organization

the process by which multiple objects in the environment are grouped, allowing us to identify those objects in complex scenes (overlapping objects, ambiguous objects, and occluding objects)

grouping

the process by which elements in a figure are brought together into a common unit or object

segregation

the process of distinguishing two objects as being distinct or discrete; understanding where one object ends and another begins

gestalt psychology

school of psychology that claimed the brain is holistic, with self-organizing tendencies; investigates three principles concerning how our perceptual systems pick out a whole from its parts: figure-ground relations, the law of Pragnanz or good fit, and laws of grouping

figure-ground organization

gestalt principle that refers to the experience viewers have as to which part of an image is in the foreground and which part is in the background of a particular scene

foreground

regarding figure-ground perception, a figure that appears in the \_______ is often below the figure that appears in the background; Ex: person would be below the sky

symmetry

feature of figure-ground perception in which a figure with symmetrical borders is more likely to be judged as being in the foreground than in the background

convex (outward bulging)

a feature of figure-ground organization in which a figure is more likely to be perceived as being in the foreground if it is perceived to be on the \_____ side of a border

concave

images with convex borders are more likely to be seen as figure, whereas those with \_____ borders are more likely to be seen as ground

perceptual grouping

gestalt principle that is the process by which visual systems combine figures with an image into wholes; using existing knowledge to place similar items together or to group images in different parts of the visual field into a perception of the same object

law of good continuation

law of proximity

law of similarity

law of symmetry

law of common fate

the five "laws" that predict how perceptual grouping occurs under a variety of circumstances

law of good continuation

gestalt law of perceptual grouping that means that figures that have edges that are smooth are more likely to be seen as continuous than those with edges that have abrupt or sharp angles; we perceive that objects continue, even if parts of them are blocked

law of proximity

gestalt law of perceptual grouping that states that elements that are close together tend to be perceived as a unified group

law of similarity

gestalt law of perceptual grouping that states elements that are similar to one another tend to be perceived as a unified group

law of symmetry

gestalt law of perceptual grouping that states that elements that are symmetrical to one another tend to be perceived as a unified group

law of common fate

gestalt law of perceptual grouping that states that elements that are moving together tend to be perceived as a unified group; ex: flock of birds in the sky

perceptual interpolation

phenomenon where a particular object may be blocked by another object, rending the physical image of the first object disjointed, yet our perceptual systems objects as continuous wholes despite that blocking

edge completion

the perception of a physically absent but inferred edge, allowing us to complete the perception of a partially hidden object; we tend to complete the image even though it may be blocked by something

illusory contours

perceptual edges that exist because of edge completion but are not actually physically present; appear to be a low-level feature of object identification; ex: kanizsa triangle

top-down approach

bottom-up approach

two approaches to recognition by components

recognition by components

theory that states that object recognition occurs by representing each object as a combination of basic units (geons) that make up that object

geons

Represent the basic units of objects and consist of simple shapes, such as cylinders and pyramids

viewpoint invariance

objects are seen as the same regardless of the vantage point relative to a viewer

dorsal pathway ; "where" pathway

pathway that works its way through the extrastriate cortex and then continues on to the parietal lobe; main function is locating objects in space and perceiving motion

ventral pathway ; "what" pathway

pathway that works its way through the extrastriate cortex and then continues on to the temporal lobe; main function is object recognition

V4

in object perception, after information leaves the V1 pathway, the next important loci is area \____ of the occipital cortex; area is linked to color vision and shape perception and edge detection; neurons have a preference for edges and respond to contours

inferotemporal

in object perception, information in the ventral pathway leaves the occipital lobe and heads into the \__________ area of the temporal lobe; specializes in detecting specific objects; damage to this area causes object agnosia

fusiform face area

a specific region in the brain designed for the recognition and distinction of familiar faces; area in the inferior temporal region critical for familiar face processing

occipital face area

region of the brain responsible for making the initial identification of a face being a face, but not its familiarity; located in the extrastriate cortex and strongly connected to the fusiform face area

fusiform face area

prosopagnosia happens if you endure damage to what area of the brain

prosopagnosia

neurological condition in which face recognition is impaired, but other forms of visual object recogntion are relatively intact; often happens due to stroke but can also be born with it; caused by damage to the inferior temporal lobe specifically the fusiform face area

parahippocampal place area

area within the inferotemporal cortex that has the specific function of scene recognition; tuned for the recognition of spatial landscapes; damage to this area results in topographic agnosia

topographic agnosia

a deficit in recognizing spatial landscapes and is related to damage to the parahippocampal place area

extrastriate body area

area of the brain that is activated when its cells view bodies or body parts but not faces

engram

area in the medial temporal lobe that is the specific location of a specific memory, such as the memory of your mom vs. any other family member, or your cat vs. another animal

visible light

wavelengths between 400-700 nm

visual spectrum (visible spectrum)

the band of wavelengths from 400-700 nm that people with the most common classes of coned vision can detect

wavelength

the distance between two peaks of light energy

decreases

as frequency increases, wavelength \_________

heterochromatic light

light consisting of many wavelengths together that are not discriminable; white light

sunlight

a form of white light that we see daily, forms rainbows when it rains because of the diffraction of the individual wavelengths

monochromatic light

light that can be produced by special light bulbs, light of only one wavelength or a very narrow band of wavelengths

spectral reflectance

the ratio of light reflected by an object at each wavelength

reflects

the color of any object is determined by the wavelengths it \______ most

achromatic

surfaces that reflect all light equally can be said to be \______ ("without color") because we usually see them as not containing color, usually white, gray, or black

white

what color surfaces reflect the most (90% of) light

gray

what color surfaces reflect 50% of light

black

what color surfaces reflect 10% of light

hue, saturation, brightness

what are the three dimensions of the color experience

hue

the color quality of light; corresponds to the color's names

quality

color is a \_____, not an amount

monochromatic colors

colors that are associated with particular wavelengths (ex: red, green, orange, yellow, blue)

nonspectral colors

combinations of more than one monochromatic color (ex: purple, brown, silver, and gold)

saturation

the purity of light; the more of this the stimulus is, the stronger the color experince. the less of this a color is, the more washed our/whitish it looks like; refers to the strength of color

brightness

related to the amount of light present and is our experience of the intensity of this light

lightness

the perceived intensity that relates to the amount of light that gets reflected by a surface

brightness usually applies to colors, lightness usually refers to the white-gray-black continuum

how is brightness different from lightness

additive color mixing and subtractive color mixing

the two main types of color mixing

additive color mixing

the creation of a new color by a process that adds one set of wavelengths to another set of wavelengths; happens when lights of different wavelengths are mixed; combination of different wavelengths that creates the diversity of colors that we see; occurs in televisions and computer screens

subtractive color mixing

the creation of a new color by the removal of wavelengths from a light with a broad spectrum of wavelengths; occurs when we mix paints, dye, or pigments; when paints mix wavelengths are deleted from what we see because each paint will absorb some wavelengths that the other paint reflects, leaving us with a smaller number of wavelengths remaining

additive color mixing happens when we mix lights of different colors, subtractive color mixing occurs when we mix paints or other colored materials

difference between additive and subtractive color mixing

pointillism

method of painting where artist uses small distinct dots of simple primary colors so that the dots blend together in a person's vision when viewed from a distance; form of additive color mixing in painting

metamer

a psychophysical color match between two patches of light that have different sets of wavelengths; consists of two patches of light that look identical to us in color but are made up of different physical combiantions of wavelengths

cones

photoreceptors in the fovae of the retinae that are responsible for high acuity and color vision

S-cone

cone that is sensitive to short-wavelength light; has a maximum response to light at 420 nm (blue)

M-cone

cone that has a maximum response to light at 535 nm (yellowish green), sensitive to medium-wavelength light

L-cone

cone that has a maximum response to light at 565 nm (yellewish red); sensitive to long-wavelength light

S cones

cones that make up only 5% of the total number of cones; more important in our perception of color than of brightness bc less sensitive to light than the other two cones

two

whats the minimum number of cone types necessary to see in color

univariance

means that any single cone system is color-blind in the sense that different combinations of wavelength and intensity can result in the same response from the cone system

cone

color vision requires more than one \_____ system

scotopic

the problem of univariance explains why we do not see color under nighttime lighting conditions, when we are under \_______ conditions we only use our rod system. because we have one class of rods, we do not see color under these conditions

trichromatic theory of color vision

theory that states that the color of any light is determined by the output of the three cone systems in our retinae

color deficiency (color blindness)

trichromatic theory predicts what happens when individuals lose one of the cone classes in their retinae, which is what deficiency?; difficiency due to differences primarily in the eye in the retina

either M or L cones

red-green color deficiency is caused by the loss of which cones

S cones

blue-yellow color deficiency is caused by the loss of which cones

opponent-process theory of color perception

theory that says that color vision is not trichromatic but organized with four primaries, or unique hues - organized in two sets of oppositional pairs (blue-yellow and red-green); explains color perception starting in the retinal ganglion cells and continuing to the lateral geniculate nucleus (LGN) and the occipital cortex

color afterimages

visual images that are seen after an actual visual stimulus has been removed (ex: if you stare at a yellow light the image behind your eyes afterwards is blue), seen as a complementary color; supporting evidence for the opponent-process theory of color vision

simultaneous color contrast

the effect that occurs when a color is surrounded by its opponent color and not by other colors or achromatic backgrounds, the color looks brighter

hue cancellation

the effect that you can cancel out the perception of a particular color by adding light of the opponent color

retinal ganglion

the first opponent cells (neurons sensitive to opposite primary colors) are seen in the \______ \_______ cells

cone-opponent cells

cells in the LGN that respond best when they are excited by the input from one cone in the center but inhibited by the input from another cone type in the surround

color-opponent cells

cells in V1 that are specific to colors themselves; may be excited/inhibited by one color in the center and inhibited/excited by its opponent color in the surround; these cells work in red-green and blue-yellow opponent pairs

double-opponent cells

class of color-sensitive cells in V1 that have a center which is excited by one color and inhibited by the other, in the surround, the pattern is reversed

all three

how many types of cones are present in the eye for newborn infants

true

true or false: infant color vision is not the same as adultlike color vision

habituation

the process of no longer responding to a repeated stimulus

dishabituation

when we respond to the change of a stimulus we had habituated to

false

true or false: adults lose cones with normal aging

lens

color perception changes in later adulthood because the \____ loses transparency to short wavelengths than for other ones, lessening our ability to see blue colors

color deficiency

the condition of individuals who are missing one or more of their cone systems; usually the result of genetic variations that prevent the development of one or more cone systems; more common in men than women

rod monochromacy

form of color deficiency in which there are no functioning cones of any kind, truly colorblind; people with this see the world in shades of gray; dependent on their rod (scotopic) vision in both bright and dim light; causes extreme sensitivity to bright lights