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What role do metamers play in the functioning of a color TV?

metamerism is the matching of apparent color of objects with different spectral power distributions. Colors that match this way are called metamers. The basis for television reproduction is the ability to make metameric color matches

What role does attention play in the occurrence of illusory conjunctions?

Illusory conjunctions are thought to occur due to a lack of visual-spatial attention. Visual spatial attention depends on fixation and (amongst others) the amount of time allotted to focus on an object. With a short span of time to interpret an object, blending of different aspects within a region of the visual field - like shapes and colors

Why is it important that cones of all three types are present at most locations on the retina?

It is important that all 3 are present in most locations because the cones are responsible for responding to a portion of the spectrum of visible light, in which you need this in almost every area of the retina in order to perceive each type of color

Why would binocular disparity not be available as a cue if the eyes saw non-overlapping views of the world?

It wouldn't be available because binocular disparity is the difference of image location seen by the left and right eyes; the eyes would be experiencing two different images if the world didn't seem overlapping

Is color vision possible with only two types of cones?

Lack of ability to see colour is the easiest way to explain this condition but in actual fact it is a specific section of the light spectrum which can't be perceived

Contrast the stimuli with which one would use smooth pursuit eye movements and saccades.

Saccade's stimuli range in amplitude from the small movements made while reading, for example, to the much larger movements made while gazing around a room. Smooth pursuit involves the tracking of a stimulus (voluntarily)

How do saccades differ from smooth pursuit eye movements?

Saccades are rapid, ballistic movements of the eyes that abruptly change the point of fixation and Smooth pursuit movements are much slower tracking movements of the eyes designed to keep a moving stimulus on the fovea.

How many types of cones does a non-color deficient human have?

Someone with normal color perception has 3 types of cones, someone who is color blind is missing one

What does the depth effect seen in a random dot stereogram tell us about the perception of depth?

Stereograms create their 3-dimensional effect by way of our retinal disparity. Each stereogram actually consists of two, partially overlapping images made up of dots, with one image for each eye. When you relax your eyes so that each image falls on about the same place on each retina, the brain can match the dots in one image to the corresponding dots in the other image, and, voila, the intended 3-D picture pops out.

What role do wavelengths play in our perception of colors?

Sufficient differences in wavelength cause a difference in the perceived hue

How does the synchrony hypothesis solve the binding problem?

Synchrony hypothesis explains that object representations are formed by synchronizing spike activity between neurons that code features of the same object

Why does a color TV have only three types of color emitting units?

Televisions are a common example of the use of additive primaries and the RGB color model. The exact colors chosen for the primaries are a technological compromise between the available phosphors (including considerations such as cost and power usage) and the need for large color triangle to allow a large gamut of colors

What is change blindness blindness

The Metacognitive Error of Overestimating Change-detection Ability

In what two ways are the depth cues of feedback from the processes of accommodation and convergence alike?

Accommodation and convergence allow us to see objects clearly both near and far without diplopia. Also, When an emmetropic person is looking at a distant object, accommodation and convergence are resting.

Contrast additive and subtractive color mixture.

Additive color is color created by mixing light of two or more different colors. Red, green, and blue are the additive primary colors normally used in additive color system. Additive color is in contrast to subtractive color, in which colors are created by subtracting (absorbing) parts of the spectrum of light present in ordinary white light, by means of colored pigments or dyes

How do color afterimages differ from simultaneous color contrast?

Afterimage is the image of a color created after staring at a certain color for an extended time; color contrast is the effect two colors have on each other when side by side

How do achromatic colors differ from chromatic colors?

An achromatic color lacks hue: so black, white, or gray. While chromatic color has a hue (blue, red)

Reflectance Edge

An edge between two areas where the reflectance of two surfaces changes

Why is binding necessary

Because there is a division of labor in the brain (importance on color, sound, smell, etc) binding gives us a unified perception of the world, combining these factors

Contrast the process whereby we see blue and the process whereby we see other chromatic colors.

Blue is perceived at the shortest wavelength, thus other colors at perceived at ranges above blue's wavelength. For example, red is at the longest wavelength

In what way are the depth cues of relative size and perspective convergence alike? (T)

Both types of depth cues, both change as the objects of interest are in the background (mountains, etc)

In what way are the depth cues of occlusion and atmospheric perspective alike?

Both types of pictorial cues when looking at an object. Both have an inhibiting factor: occlusion: one object partially covers up another, and atmospheric perspective; the distant objects are fuzzy and have a blue tint

How does inattention blindness differ from change blindness

Change blindness and inattentional blindness are both failures of visual awareness. Change blindness is the failure to notice an obvious change. Inattentional blindness is the failure to notice the existence of an unexpected item.

What role does attention play in conjunction search?

Conjunction searches occur in the focused attention stage, and takes a longer time than feature search because it requires conscious attention and effort to combine features

What is the role of attention in inattention blindness and change blindness?

Divided visual attention is necessary in IB to see a stimulus, while focused visual attention is necessary for CB because CB is stronger when change is unexpected.

What role do feature detectors play in the occurrence of illusory conjunctions?

Feature detection is the ability to detect certain types of stimuli; specialized brain cells for these are called feature detectors. In illusory conjunctions; features such as the letters, and color is detected, however, maybe be wrongly bonded to each other

What role doe feature detectors play in feature search

Feature detectors are cells that recognize features such as color, shape, etc, these are fired in feature search.

What role does attention play in feature search?

Feature search occurs in the pre attention stage, and can be performed quickly (color, shape); does not require conscious attention and effort

According to Treisman, does binding occur during the preattentive or the focused attention stage?

Focused Attention Stage

How do color matching experiments provide support for the trichromatic part of our color vision theory?

Helmholtz used color-matching experiments where participants would alter the amounts of three different wavelengths of light to match a test color. Participants could not match the colors if they used only two wavelengths, but could match any color in the spectrum if they used three.

Give an example of a corresponding point in the two retinas.

Holding a finger up and focusing on the wall behind it

What fact about vision is used in the depth cue of movement parallax?

Monocular cues of vision are used in the motion parallax

What fact about vision is used in the size-based depth cues?

Monocular vision is used in regards to size-based depth cues; both eyes are used separately

Could you make a color TV using colors other than red, green, & blue?

No, because these three colors represent every wavelength needed in the color spectrum

Which of the three spatial dimensions is the most difficult for us to locate objects upon?

One dimensional space

How is performance limited in the Stroop task?

Performance is limited because there is a disconnect between the color of the word and the actual word; thus slows the response of the observer

What role do color and form and location and motion information play in binding?

Processing of these features of attribute dependent and are processed at different time lengths: color is perceived before motion but takes longer time for binding

What is the physical basis of the psychological attribute of saturation?

Pureness

How is a random dot stereogram constructed?

Random-dot stereogram (RDS) is stereo pair of images of random dots which when viewed with the aid of a stereoscope, or with the eyes focused on a point in front of or behind the images, produces a sensation of depth, with objects appearing to be in front of or behind the display level.

Visual Angle

The angle formed at the eye by rays from the extremities of an object viewed.

Pigments are involved at two points in the process whereby a color like red is perceived. What do pigments do in this process?

The chemical basis of vision depends upon the absorption of light (electromagnetic radiation) by special pigments in the eye. These pigments are transducers: they convert electromagnetic energy into the chemical energy that can initate (stimulate) an impulse within a nerve cell (neuron).

How does our color vision theory explain the symptoms of people with tritanopia, deuteranopia, and protoanopia?

The different anomalous conditions are protanomaly, which is a reduced sensitivity to red light, deuteranomaly which is a reduced sensitivity to green light and is the most common form of colour blindness and tritanomaly which is a reduced sensitivity to blue light

Why could a stereoscope not create the illusion of depth for a white wall?

The eyes must be focused on two images; a wall would not be able to be projected

How do results observed for patients with Balint's syndrome argue for Treisman's theory?

The lesions produced severe deficits in locating and reaching for objects, and difficulty in seeing more than one object at a time, resulting in a neuropsychological diagnosis of Balint's syndrome. The pattern of deficits supported predictions of Treisman's Feature Integration Theory (FIT) that the loss of spatial information would lead to binding errors.

What is the most important difference between the different types of cones?

The most important difference in the types of cones is the difference of wavelengths able to be perceived. (long, middle, or short) all representing different colors

How does our color vision theory explain the fact that we see a green afterimage when we look at red for a long time and then look at white?

The opponent color theory suggests that there are three opponent channels one being red vs green. When red is seen, a green after image is produced

Why is it to so difficult for us to locate objects upon this dimension?

The particles of a one dimensional object are too small for the human eye to see

What is the principle of univariance?

The probability that a given photon of light will be absorbed by the photopigment depends on its wavelength, all subsequent events within the receptor are independent of wavelength. A single type of cone cannot distinguish color from luminance

Why is it important that the three types of cones are sensitive/responsive to overlapping bands of wavelengths?

The three types of cones respond to all wavelengths at some extent, however just because one is triggered for a certain wavelength doesn't mean that certain color will be perceived.

Correspondence Problem

The visual system's matching of points on one image with similar points on the other image in order to determine binocular disparity

What role does attention play in binding

There is a division of attention when it comes to binding. Certain parts of the brain bring its attention to specific items such as vision, hearing, or touch

What are the necessary conditions for observing an illusory conjunction in the lab?

This occurs when people don't bind attributes to the right objects. Two conditions that contribute to this are color and time; if a person is quickly flashed a blue S and a red R; they may report seeing a red S (illusory conduction)

What factors determine where an observer fixates in a scene?

Top down (task or goals) and bottom up factors (color, contrast) determine where we look in a scene

Contrast the role of top-down and bottom-up processing in guiding eye movements.

Top down processing and factors are task or goals that contribute to the eye's focus and bottom up processing are stimuli that attract attention because of attractive properties (color, shape, etc)

How do the results observed for feature and conjunction search argue for Treisman's theory?

Treisman distinguishes between two kinds of visual search tasks, "feature search" and "conjunction search". Feature searches can be performed fast and pre-attentively for targets defined by only one feature, such as color. Features should "pop out" during search and should be able to form illusory conjunctions. Conversely, conjunction searches occur with the combination of two or more features and are identified serially. Conjunction search is much slower than feature search and requires conscious attention and effort.

How do illusory conjunctions argue for Treisman's attentional theory?

Treisman's attention theory suggests that that features are registered early automatically and in parallel while objects are identified separately. So if flashed quickly, an individual may interpret the objects they see as being something when they actually aren't. Similar to illusory conjunctions

What sort of light is necessary to the perception of the color white?

When perceiving the color white, it is much easier in doing so in very low lit areas; because the rods (sensitive to black and white) are sensitive in high light areas.

What is the relationship between eye movements and selective attention?

When the pre-attentive and attentive stages have determined the position of the target, the eye must be moved in such a way that the target object can be inspected with a higher acuity, by foveating the object.

Illumination Edge

the border between two areas created by different light intensities in the two areas

How does our color vision theory explain the fact that we don't see things that are reddish green or bluish yellow?

the opponent-process theory states that the cone photoreceptors are linked together to form three opposing colour pairs: blue/yellow, red/green, and black/white. Activation of one member of the pair inhibits activity in the other. Consistent with this theory, no two members of a pair can be seen at the same location, which explains why we don't experience such colours as "bluish yellow" or "reddish green".

Why can't we directly infer the size of an object from the size of the object's retinal image?

the size of the image on the retina changes as the distance from the object to the observer changes; so we can't directly infer the actual size of object

What is simultaneous color contrast?

the tendency of a color to induce its opposite in hue, value and intensity upon an adjacent color and be mutually affected in return