Sensation and Perception- TEST ONE
Info in LGN is best described as ____________________________.
BI-DIRECTIONAL, WITH SIGNALS COMING FROM RETINA AND CORTEX TO THE LGN.
Rods and cones synapse with _____ cells, which then synapse with _______ cells.
BIPOLAR; GANGLION
A participant is viewing black & white (full contrast) grating stimulus with a cycle subtending two arcminutes of visual angle. If the photoreceptors in line with this grating have receptive fields of slightly under 1 arcminute (e.g. centers of the receptors are just under 1 arcminute apart) the stimulus will likely be perceived as ________________; If the photoreceptors have receptive fields of 1.5 arcminutes, the stimulus will likely be perceived as ___________.
BLACK AND WHITE BARS; A SOLID GRAY PATCH
Vera adapts to a yellow stimulus for about 60 seconds. If she looks at a white surface and blinks, the after image she sees will appear to be ______.
BLUE
Color may play role in determining _____.
FORM; form and color linked physiologically by neurons with side-by-side receptive fields
Dr. Lanzilotti wants to create a stimulus that will produce an afterimage of a red heart shape against a white background. He should make the heart _____ and the background _____.
GREEN; BLACK
Blue & yellow painted mixed yields ______; blue & yellow lights mixed yields _______.
GREEN; WHITE
If you cover the penumbra with a black marker, the perception of the border ______________.
CHANGES FROM AN ILLUMINATION EDGE TO A REFLECTANCE EDGE.
The double the perceived brightness of a light you need to multiply the physical intensity of the light by about 9. This is an example of response _____.
COMPRESSION
The difference between the METHOD OF LIMITS and the METHOD OF ADJUSTMENT is that in the method of adjustment, stimulus intensity is changed at a ______ manner
CONTINUOUS
The structure of the eye that provides about 80% of eye focusing power is the _____.
CORNEA
When visual pigments become bleached they are _______________.
DETACHED FROM THE OPSIN.
In Ungerleider & Mishkins (1982) research monkeys who had had their temporal lobes removed had difficulty _______________.
DISCRIMINATING BETWEEN OBJECTS.
RESPONSE BIAS
Differences in response criteria exist among participants
Finding the neural correlates of consciousness is related to the ________________.
EASY PROBLEM OF CONSCIOUSNESS
EXTRASTRIATE BODY AREA
EBA; body parts
PRESBYOPIA
"old eye" ; distance of near point increases, due to hardening of lens and weakening of ciliary muscles
WAVELENGTH SENSITIVITY CONES
(S) BLUE; (M) GREEN; (L) RED
MAGNITUDE ESTIMATION
(scaling) stimuli are above threshold, observer given a standard stimulus and a value for its intensity; observer compares standard stimulus to test stimuli by assigning numbers relative to the standard; response compression and expansion
PROCES NEEDED FOR TRANSDUCTION
1) retinal molecule changes shape 2) opsin molecule separates 3) retina shows pigment bleaching 4) retinal and opsin must recombine to respond to light 5) cone pigment regenerates in 6 mins 6) rod pigment takes over 30 mins to regenerate
Considering Weber's work with JNDs, if a person was just able to notice the difference in weight b/t a 500 g weight & a weight 10g higher, we could reasonably expect the lowest difference this could detect between a 1000g weight & another weight would involve a weight ____ g heavier.
20
Demetri is a participant in an auditory detection study using the METHOD OF CONSTANT STIMULI. He never detects the 10 unit tone. He detects the 20 unit tone 25% of trials, detects the 30 unit tone 50%, 40 unit tone 80%, and 50 unit tone 95%. His threshold for hearing tones would be taken as the _______.
30 unit tone
An electrode is placed in an orientation column that responds best to orientations of 45 degrees. The adjacent column of cells will probably best respond to orientations of ____ degrees.
40
Visible light is between __________ nm within the electromagnetic spectrum.
400 and 700
Visual spectrum range ____ nm to _____nm
400 nm (blue) to 700 nm (red)
CONES
5 million; daylight, mostly in fovea (small area of extremely sharp vision), high acuity, low sensitivity; one on one convergence, need more light to respond than rods; 6 peripheral cones to one ganglion;
ROD
90 million; night vision; only in periphery; low acuity, high sensitivity, achromatic (no color); greater convergence (many rods into ganglion cells, increases response, no detail) 120 rods to one ganglion
LGN received _____ of input coming from optic nerve.
90%
RESPONSE CRITERION
A persons individual response bias
After training participants of the recognition of Greeble stimuli, Gauthier et. al. found that the neuron in the FFA responded _________________.
ABOUT AS WELL TO GREEBLES AS HUMAN FACES.
When shown a picture of a sparrow, Kathy most quickly says "bird," slightly later coming up with "sparrow." For Kathy "bird" serves as _______.
ENTRY LEVEL CATEGORY
Response __________ occurs in a magnitude estimation experiment often doubling the stimulus intensity ______ than doubles the subjective magnitude of the stimulus.
EXPANSION; MORE
Distance when light becomes focused is called the _______ past which focus is impossible without artificial correction.
FAR POINT
FUSIFORM FACE AREA
FFA; faces
SENSATION
Ability to detect a stimulus and perhaps to turn that detection into a private experience
Opsin separates from retinal, must recombine before cell can _______
FIRE TO LIGHT AGAIN
RESOLUTION ACUITY
finest high contrast detail we can visually resolve; chiefly determined by spacing of retinal photoreceptors; visual system samples grating stimulus through discrete receptors
VISUAL CORTEX NEURONS
fire to specific features of a stimulus; pathway away from retina shows neurons that fire to more complex stimuli
METHOD OF CONSTANT STIMULI
five to nine different intensities are presented in random order, multiple trials presented. threshold is the intensity that results in detection in 50% of the trials
MACULAR DEGENERATION
fovea and small surrounding area are destroyed; creates "blind spot" on retina; most common in older individuals
PENUMBRA
fuzzy outline at the edge of a shadow; signals an illumination edge
ON CENTER CELLS
ganglion cell preference; increase firing rate when middle of receptive field stimulated and decreased firing rate when outer area of receptive field stimulated
RETINITIS PIGMENTOSA
genetic disease; rods are destroyed first; foveal cones can also be attacked, several cases result in complete blindness
If entire cycle covered by single cone's receptive field, pattern is lost and we perceive ____
gray field
Receptive field must be smaller than _____ the period of the sine wave to perceive texture.
half
COLOR VISION BENEFITS
helps us classify and identify objects; facilitate perceptual organization of elements into objects; evolutionary advantage in foraging for food
OPPONENT-PROCESS THEORY
hering; color vision is caused by opposing responses generated by blue and yellow, and green and red; if you cant see red then you cant see green, cant see yellow then cant see blue; pairs respond in opposing fashion -> chemical reactions in retina; explains neural response for cells connected to the cones further in the brain -later perceptual system
HARD PROBLEM OF CONSCIOUSNESS
how do physical responses cause experience?
SURROUNDEDNESS
if one region is entirely surrounded by another, it is likely that the surrounded region is the figure
ASTIGMATISM
if shape of cornea is not symmetrical light will not focus correctly; vertical and horizontal light rays may focus different points before/behind retina
Amount of light reaching eye depends on:
illumination and object's reflectance
OCCULAR DOMINANCE COLUMNS
in LGN cells respond to only one eye or the other; in V1 preferential activation for one eye
LATERAL GENICULATE NUCLEUS (LGN)
in thalamus; major function is to regulate neural info from the retina to visual cortex
ACHROMATIC
lacking color (white, gray, black)
PHOTOPIC (DAY) VISION
light is bright enough to stimulate cone receptors and bright enough to saturate rod
SCOTOPIC (NIGHT VISION)
light is bright enough to stimulate rod receptors but not enough to stimulate cone receptors (night vision)
HYPERCOLUMN
location column with a full range of orientation columns
CEREBRAL ACHROMATOPSIA
loss of ability to see color due to damage to the brain; other damage cause including prosopagnosia (inability to recognize faces) --> color perception results from activity in many different visual areas
ACUITY
measure of the smallest spatial detail that can be accurately perceived
METHOD OF ADJUSTMENT
method of limits in which subject controls the change in the stimulus (like adjusting the stereo volume); repeated trials averaged for threshold
JUST NOTICEABLE DIFFERENCE
minimal difference between two stimuli that can be correctly distinguished from each other; discrimination between two stimuli
PROTANOPIA
missing long wavelength pigment; sees short wavelengths as blue; as wavelengths increases, blue becomes less saturated until hitting neutral point (perceived as gray); above neutral point, they see yellow which becomes less intense at longer wavelengths
DEUTERANOPIA
missing the medium wavelength pigment; perceptually very similar to protanopia; individuals see short wavelengths as blue; above neutral point they see yellow
TRITANOPIA
missing the short wavelength pigment; not linked to x-chromosome; individuals see short wavelengths as blue, above neutral point they see red
ADDITIVE COLOR MIXTURE
mixing lights of different wavelengths; all wavelengths are available for the observer to see; ADDING new wavelengths to the existing light (blue light + yellow light = white light)
SUBTRACTIVE COLOR MIXTURE
mixing paints with different pigments; additional pigments reflect fewer wavelengths; each component paint still absorbs the same wavelengths as before, so the only wavelengths reflected from the combination are those reflected by BOTH paints (blue paint + yellow paint = green paint)
EFFERENT NEURONS
motor neurons; generate responses in muscles and glands
MYOPIA
nearsightedness; eye too long, cannot focus on far objects
ANOMALOUS TRICHOMAT
needs three wavelengths, like in normal vision, but mixes them in different proportions than normal trichromats; impaired ability to discriminate between wavelengths that are close together
EASY PROBLEM OF CONSCIOUSNESS
neural correlate of consciousness (NCC) how physiological responses correlate with experience
ORIENTATION COLUMNS
neurons within columns fire maximally to the same orientation of stimuli; adjacent columns change preference in orderly fashion (within location columns)
PERCEPTION OF LIGHTNESS
not related to the amount of light reflected by an object (which is dynamic); is related to the percentage of light reflected by an object (which is static)
VISUAL SEARCH
observers look for one stimulus in a set of many stimuli
PRINCIPLE OF UNIVARIANCE
once a photon of light is absorbed by a visual pigment molecule, the identity of the light's wavelength is lost; we only have the AMOUNT absorbed to go on
SPARSE CODING
only a relatively small number of neurons are necessary for an object in distributed coding; can be viewed as midpoint between specificity and distributed coding
DISTRIBUTED CODING
pattern of firing across many neurons codes specific objects; large number of stimuli can be coded by a few neurons
BRIGHTNESS
perceived intensity of the color (light blue vs dark blue)
COLOR CONSTANCY
perception of colors as relatively constant in spite of changing light sources
MONOCHROMAT
person with only one receptor mechanism; world in grayscale; needs only one wavelength to match any color in the spectrum; rare typically hereditary; usually only rods, no functioning cones; low acuity vision
DICHROMAT
person with two receptor mechanisms; needs two wavelengths to match any other color
BLIND SPOT/OPTIC DISC
place where optic nerve leaves eye (no receptors here); located on edge of visual field
GOOD CONTINUATION
points that when connected result in straight or smooth curves belong together/objects partially covered by other objects are seen as continuing behind the covering object
VENTRAL STREAM
processes what info; PPA, FFA, EBA
DORSAL STREAM
processes where (and how) information; fast but colorblind; location and action
CHROMATIC ADAPTATION
prolonged exposure to chromatic color leads to receptors: adapting when stimulus color selectively bleaches a specific cone pigment, decreasing in sensitivity to color; occurs to light sources leading to color constancy
GLOBAL SUPERIORITY EFFECT
properties of a whole/larger object take precedence over smaller parts on the object
TYPES OF DICHROMATISM
protanopia, deuteranopia, tritanopia
METHOD OF LIMITS
psychophysical method in which the particular dimension of a stimulus, or the difference between two stimuli, is varied incrementally until the participant responds differently (HEARING TEST); crossover point is threshold
LOCATION COLUMNS
receptive fields at same location on the retina are within a column
VIEWPOINT INVARIANCE
recognizing objects regardless of viewing angle
REFLECTION
redirect something that strikes a surface- esp light, sound or heat- usually back toward point of origin; mirror
OCCLUSION RELATEABLE SHAPES
relatability is the degree to which two line segments appear to be a part of the same contour; smooth convex or concave curve -> relatable; s curve required -> unrelatable
UNGERLEIDER & MISHKIN EXPERIMENT
removing part of parietal lobe in monkey resulted in problems with landmarks discrimination (where pathway); removing part of temporal lobe in monkey resulted in problems with the object discrimination task (what pathway)
COMPLEX CORTICAL CELL CHARACTERISTICS
responds best to movement of a correctly oriented bar across the receptive field. many cells respond best to a particular direction of movement
END-STOPPED CORTICAL CELL CHARACTERISTICS
responds to corners, angles, or bars of a particular length moving in a particular direction
ACCOMODATION
results when ciliary muscles are tightened which causes lens to thicken
ISOMERIZATION
retinal changes its shape; triggers enzyme cascade (enzymes facilitate chemical reactions, cascades means that a single reaction leads to increasing numbers of chemical reactions = how isomerizing one pigment leads to the activation of a rod receptor)
ROD DARK ADAPTATION BEHAVIOR
rods overwhelmed with moderately bright light; keyed to low light vision, can detect a single photon on light; recover sensitivity after being overwhelmed slowly
AMACRINE CELLS
run laterally among bipolar and ganglion cells; implicated in contrast enhancement and detection of changes in light pattern over time, but precise function is still unknown
AFFERENT NERVES
sensory neurons; transduce signals (e.g. vision, hearing, and touch)
LGN PATHWAYS/FEEDBACK
signals are received from retina, the cortex and brain stem and thalamus; signals are organized by eye, receptor type, and type of environmental info
SIMILARITY
similar things are grouped together
ACCIDENTAL VIEWPOINT
single, precise viewing position that leads to an erroneous regularity grouping of the visual image that is not present in reality
Spatial frequency:
specific cells have receptive fields that tune them to see spots of a certain size
SPECIFICITY CODING
specific neurons responding to specific stimuli; leads to "grandmother cell" hypothesis; recent research shows cells in hippocampus that respond to concepts like halle berry; problems: too many different stimulus to assign specific neurons; most neurons respond to a number of different stimuli
MIDDLE VISION
step that comes after low-level processes (line, shape, color, angle) but before object recognition (high level); finding edges, texture, segmentation and grouping, figure and ground, occlusion, parts and wholes; decipher blurry faces
DOUBLE OPPONENT NEURONS
suggested as important in perception of boundaries between two different colors
SINGLE OPPONENT NEURONS
suggested as important in perception of color within regions
MEMORY COLOR
the effect on perception of prior knowledge of the typical colors of objects; the colors of very familiar objects are judged as richer and more saturated than are the colors of unfamiliar objects reflecting the same wavelengths
If dark & light bars of given cycle land on separate cones we see ____
the pattern
SIZE
the smaller region is more likely to be figure; car smaller than road, plane smaller than sky
METAMERS
the stimuli in metamerism (single wavelength light vs combination of 3 different wavelengths of light); look alike because they both elicit same response pattern in the 3 cone receptors (green- large response in M receptor, red- large response in L receptor)
When using the METHOD OF CONSTANT STIMULI the ABSOLUTE THRESHOLD is determined by calculating
the stimulus intensity detected 50% of the time
COMMON FATE
things moving in same direction are grouped together
PROXIMITY/NEARNESS
things that are near to each other are grouped together
REACTION TIME
time from presentation of stimulus to observer's response is measured (measures visual search)
REFRACTION
to alter the course of a wave of energy that passes into something from another medium, as water does to light entering it from the air (lens/eye); faster medium to slower medium like air to water, from slower medium to faster medium like water to air_
INTER NEURONS
transmit and process signals: inhibit or facilitate other nerves to fire
SELECTIVE TRANSMISSION
transparent objects, such as liquids, selectively allow wavelengths to pass through
UNILATERAL DICHROMAT
trichromatic vision in one eye and dichromatic in other
RATIO PRINCIPLE
two areas that reflect different amounts of light look the same if the ratios of their intensities are the same
SIGNAL DETECTION THEORY
used to take individuals response criteria into account
VENTRAL PATHWAY
what
SELECTIVE REFLECTION
when some wavelengths are reflected more than others (chromatic colors or hues occur when this happens: blue, green, red)
METAMERISM
when two physically different stimuli are perceived identically
OPTIC CHIASM
where inner visual fields cross other hemispheres
DORSAL PATHWAY
where/how
EDGE ENHANCEMENT
white figure tends to appear brighter than background
TRICHROMATIC THEORY OF COLOR VISION
young and helmholtz; three different receptor mechanisms are responsible for color vision; based on color matching procedure; light of a given wavelength stimulate a given receptor mechanism to varying degrees; explains the responses of the cones in the retina -early visual system
Cerebral achromatopsia is when a person ______________________.
HAS NORMAL CONE FUNCTIONING, BUT CANNOT EXPERIENCE COLOR DUE TO A BRAIN INJURY.
A unilateral dichromat ____________________.
HAS TRICHROMATIC VISION IN ONE EYE AND DICHROMATIC VISION IN THE OTHER EYE.
If a kitten is raised in an environment of just horizontal lines, the kitten would _____________________.
HAVE CORTICAL CELLS THAT RESPOND TO HORIZONTAL LINES, BUT FEW/NONE TO VERTICAL LINES
The edge between a dark shadow and an illuminated checkerboard is an _________
ILLUMINATION EDGE.
The PRINCIPLE OF SIMILARITY can account for grouping of stimuli that are similar _____________.
IN ORIENTATION, SHAPE, AND SIZE.
Prosopagnosia is an ________________.
INABILITY TO RECOGNIZE FAMILIAR FACES.
Convergence (e.g. the input of multiple rods ultimately impacting a single ganglion cell) results in _________ sensitivity and _______ acuity.
INCREASED; DECREASED
Two receptor types let us distinguish wavelengths _____________.
INDEPENDENT OF LIGHT INTENSITY.
INFEROTEMPORAL CORTEX
IT CORTEX; IT cells respond specifically to certain items; for example firing vigorously to the sight of a face
Weber's Fraction
JND change relative to physical intensity stimulus: if you notice difference between 40g and 41g you can tell difference between 400g and 410g
Peripheral cones ___ densely packed than foveal cones.
LESS
Types of striate cortex
LOCATION, ORIENTATION, OCCULAR DOMINANCE
A ____ focal length provides a narrow field of view
LONG
The first step in the procedure for __________ is to present to the participant a standard stimulus & assign a numerical value to that stimulus.
MAGNITUDE ESTIMATION
Color constancy works best when an object is surrounded by ______ colors.
MANY
Participants perceive a 620 nm pattern as being redder if that pattern has the shape of a stop sign rather than a mushroom shape demonstrates ________.
MEMORY COLOR
ABSOLUTE THRESHOLD
MINIMAL amount of stimulation necessary for a person to detect the stimuli 50% of the time; discrimination between stimulus presence or absence
A neuron with an excitatory center, inhibitory surround receptive field will respond most when we stimulate ________.
ONLY THE CENTER
Differences in the structure of _____ are responsible for the different absorption spectra.
OPSIN
Two main components to pigment molecules
OPSIN (large protein) and RETINAL (light sensitive molecule)
The _______ carries information from the retina toward the brain.
OPTIC NERVE
SIGNAL PATHWAYS FROM RETINA TO BRAIN
Optic nerve -> Optic chiasm -> LGN -> 2 pathways to temporal lobe (ventral & parietal) -> Frontal lobe
Color perception depends on the _________ in three receptor mechanisms.
PATTERN OF ACTIVITY
Light when traveling can be described in terms of wavelength or particularly when absorbed as, as consisting of small packets of energy called _______.
PHOTONS
Rods and cones (_____) -> _______ -> _______ -> ______
PHOTORECEPTORS; HORIZONTAL CELLS; BIPOLAR CELLS; GANGLION CELLS
The EBA is activated by __________.
PICTURES OF BODY PARTS.
PARAHIPPOCAMPAL PLACE AREA
PPA; scenery, locations
The Olympic symbol is an example of the Gestalt principle of ______________.
PRAGNANZ/GOOD FIGURE/SIMPLICITY
Light enters the eye through the ____ and is focused by the ____ and ____ to a sharp image on the _____.
PUPIL; CORNEA; LENS; RETINA
Lorelei's mother is 60. B/c of the condition called _____, the closest distance at which she can focus an object is probably about _________.
Presbyopia; 100 cm.
The major dependent variable used in the VISUAL SEARCH METHOD is _______.
REACTION TIME
Basic colors in color circle are: ________.
RED, GREEN, BLUE, YELLOW
The reflectance curve for a white piece of paper would _________________.
REFLECT LONG, MEDIUM, & SHORT WAVELENGTHS EQUALLY.
If you look at a folded index card through a pin hole, you see the border formed by the crease as a ___________ because the card looks ______.
REFLECTANCE EDGE; FLAT
Colors of objects are determined by the wavelengths of _____ light
REFLECTED
Visual transduction (convergence of light energy to chemical and ultimately electrical signals for processing) occurs when the ______ absorbs one photon of light.
RETINAL
_________ reacts to light to start the process of transduction.
RETINAL
The ____________ can be described as the electronic map of the retina on the cortex.
RETINOTOPIC MAP
_____ AND ____ are the visual receptors in the _____ that contain visual pigment.
RODS; CONES; RETINA
Activity in the PPA is the ____________________.
SAME FOR PICTURES OF FURNISHED AND EMPTY ROOMS
A _____ focal length provides a wide field of view.
SHORT
The theory that accounts for response criterion in a detection experiment is __________.
SIGNAL DETECTION THEORY
Least likely represented system to be in place in human visual system: ________
SPECIFICITY CODING
NOTE ABOUT WAVELENGTH SENSITIVITY
Since rods are insensitive to higher wavelengths (red), we can use red light for additional illumination at night without affecting our night vision (we stay dark adapted)
The difficulty of reading under dim light conditions can be explained by ___________________.
THE FACT THAT ROD FUNCTIONING PREDOMINATES DURING DARK ADAPTATION, THEREFORE POOR ACUITY.
The cortical magnification factor occurs in humans because _______________.
THE SMALL AREA OF THE FOVEA ACCOUNTS FOR A LARGE AREA OF THE CORTEX
When looking at a scene, the different sections of the scene are processed by many different location columns. Through the use of a ll the location columns the entire scene can be perceived. This effect is referred to ______.
TILING
TRANSDUCTION
The process of transforming energy in the environment into electrical energy in the neurons
The ability to readily recognize differently angled views of an object as the same object is an example of ____________.
VIEWPOINT INVARIANCE
We conceptualize light as a ________ when it travels and a _____ stream of photons when absorbed.
WAVE; PARTICLE
The blind spot, or optic disc, is located ___________.
WHERE THE OPTIC NERVE LEAVES THE EYE
A non-accidental T-junction typically indicates that________________.
YOU ARE SEEING MORE THAN ONE OBJECT IN THAT AREA, WITH ONE IN FRONT OF THE OTHER.
SYMMETRY
a symmetrical region is more likely to be figure
CORTICAL MAGNIFICATION
acuity drops off as the image moves away from the fovea; entire visual system from receptors to cortex emphasize central vision; a small area of the fovea is represented by a large area on the visual cortex
SATURATION
adding white to a color makes it less saturated; strength of the hue (white, pink, red)
LENS
adjusts shape for object distance; 20% of vision
DOUBLE DISSOCIATION
after brain damage some individuals have difficulty recognizing faces but can recognize objects or vice versa
Y AND ARROW JUNCTIONS
almost always indicate object corners (no occlusion)
T-JUNCTION
almost always occur wen one object is occluding another
CATARACT
alterations to crystal in lens creates regions of increased capacity; interferes with vision through increased absorption and scattering of light
GRATING STIMULI
alternating dark and light bars; measured by acuity
SELECTIVE REARING
animals reared in environments that contain only certain types of stimuli; neurons that respond to these stimuli will become more dominant due to neural plasticity; Ex: rearing kittens in tubes with either horizontal or vertical lines; both behavioral and neural responses shared the development of neurons for the environmental stimuli
RECEPTIVE FIELD
area of the retina at which stimulation alters the firing pattern of the ganglion cell (increase or decrease)
REPONSE EXPANSION
as intensity INCREASES the perceived magnitude INCREASES MORE QUICKLY than the intensity (I.E. SHOCK)
RESPONSE COMPRESSION
as intensity INCREASES, the perceived magnitude increases more SLOWLY than the intensity (I.E. BRIGHTNESS)
SINE WAVES
building blocks for understanding visual and auditory perception; defined by amplitude and frequency; shape is "sinusoidal" with rounded peaks unlike other types of waves like those we see breaking on a beach
OPTIC NERVE FIBER (GANGLION CELL) CHARACTERISTICS
center-surround receptive field, responds best to small spots, but will also respond to other stimuli
LGN CHARACTERISTICS
center-surround receptive fields very similar to receptive field of a ganglion cell
Object recognition
changes in rotation, distance, lighting, occluded view
INTENSITY
changes perceived brightness
HUE
chromatic aspect of color (red, blue, yellow, etc)
COLOR AFTERIMAGES
color flipped version of an image that remains after staring at one particular image for a while, fatiguing receptors
TILING
columns working together to ensure the entire visual field is covered
CONE DARK ADAPTATION BEHAVIOR
cones much less sensitive, greater operating range; need at least 10 photons per second, up to hundreds of thousands per second; recover sensitivity quickly
HORIZONTAL CELLS
connect photoreceptor cells horizontally; allow for lateral inhibition which lets ganglion cells react to information on differences in activation between groups of photoreceptors
UNIFORM CORRECTNESS
connected region of visual properties are perceived as single unit
ILLUSORY CONTOURS
contours that appear real but have no real physical edge
BEHAVIOR OF PATIENT WITH D.F.
damage to vertical pathway due to gas leak; not able to match orientation of card with slot but able to match orientation if placing card in slot -> double dissociation between ventral and dorsal pathways
OFF BIPOLAR
detection of decrease in light
ON BIPOLAR
detection of increase in light
NEAR POINT
distance at which the natural lens can no longer adjust for a closer object
ILLUMINATION EDGES
edges where lighting of two surfaces changes (different lighting, shadow)
REFLECTANCE EDGES
edges where the amount of light reflected changes between two surfaces (different material)
SIMULTANEOUS COLOR CONTRAST
effect that occurs when surrounding an area with a color changes the appearance of the surrounded area
COMMON REGION
elements in same region tend to be grouped together
PRAGNANZ/GOOD FIGURE/ SIMPLICITY
every stimulus is seen as simply as possible
SIMPLE CORTICAL CELL CHARACTERISTICS
excitatory and inhibitory areas arranged side by side. responds best to bars of a particular orientation
ON CENTER, OFF SURROUND
excited by central light, inhibited by peripheral light. When both center and surround stimulated a subtle response on ONset and OFF set; center OFF, ON surround is opposite
HYPEROPIA
farsightedness; eye too short, cannot focus on near objects
PERCEPTION
Act of giving meaning to a detected sensation
SINE WAVE GRATINGS
Amplitude (contrast); Frequency (cycles/degree); Phase; Orientation (rotation)
A researcher finds that damage to Area A in brain results in loss of Function A but not Function B. In another individual, damage to Area B results in loss of Function B, not to Function a. Results can be described as __________.
DOUBLE DISSOCIATION
