Week 8 Readings Flashcards
1
Q
What is electromagnetic energy?
A
Pulses of energy waves that can carry information from place to place
2
Q
What is wavelength?
A
The distance between one wave peak and the next wave peak
3
Q
our eyes detect only the range from about ____ to ____ billionths of a meter, the part of the electromagnetic spectrum known as the _____________.
A
our eyes detect only the range from about 400 to 700 billionths of a meter, the part of the electromagnetic spectrum known as the visible spectrum.
4
Q
What is the visible spectrum?
A
The part of the electromagnetic spectrum that our eyes detect (only the range from about 400 to 700 billionths of a meter)
5
Q
Through what does light enter the eye?
A
the cornea
6
Q
What is the cornea?
A
A clear covering that protects the eye and begins to focus the incoming light
7
Q
What is the iris?
A
The coloured part of the eye that controls the size of the pupil by constricting or dilating in response to light intensity
8
Q
When we enter a dark movie theatre on a sunny day, for instance, muscles in the iris ___ (1) the pupil and allow more light to enter. Complete adaptation to the dark may take up to ____ (2) minutes.
- a) open b) close
- a) 10
b) 14
c) 15
d) 20
e) 30
A
When we enter a dark movie theatre on a sunny day, for instance, muscles in the iris open the pupil and allow more light to enter. Complete adaptation to the dark may take up to 20 minutes.
9
Q
What is the lens?
A
A structure that focuses the incoming light on the retina
10
Q
What is the retina?
A
Cell layer in the back of the eye containing photoreceptors.
11
Q
What is visual accommodation?
A
The process of changing the curvature of the lens to keep the light entering the eye focused on the retina
12
Q
How do rays from the left side of an image interact with the retina?
A
Rays from the left side of an image strike the right part of the retina, and vice versa.
13
Q
How does the image on the retina differ from our final perception?
A
The image projected on the retina is flat, but our final perception of the image is three-dimensional.
14
Q
Why is the image on the retina upside down and backward?
A
The rays from the image strike opposite sides of the retina, causing the image to be upside down and backward.
15
Q
What happens when the focus is in front of the retina?
A
When the focus is in front of the retina, the person is nearsighted.
16
Q
What happens when the focus is behind the retina?
A
When the focus is behind the retina, the person is farsighted.
17
Q
How do eyeglasses and contact lenses correct vision problems like nearsightedness and farsightedness?
A
Eyeglasses and contact lenses correct vision problems by adding another lens in front of the eye to adjust the focus.
18
Q
How does laser eye surgery correct vision?
A
Laser eye surgery corrects vision by reshaping the eye’s own lens to properly focus light on the retina.
19
Q
What is nearsightedness?
A
When the focus is in front of the retina
20
Q
What is farsightedness?
A
When the focus is behind the retina
21
Q
What is the optic nerve?
A
A collection of millions of ganglion neurons that sends vast amounts of visual information, via the thalamus, to the brain
22
Q
What are the receptor cells in the retina that respond to light?
A
The receptor cells are known as rods and cones.
23
Q
After rods and cones are activated, which cells do they activate next in the retina?
A
They activate the bipolar cells.
24
Q
Which cells gather together to form the optic nerve?
A
The ganglion cells gather together and form the optic nerve.
25
What is the optic nerve, and what is its function?
The optic nerve is a collection of millions of ganglion neurons that sends visual information to the brain via the thalamus.
26
Why are the retina and optic nerve considered an extension of the brain?
The retina and optic nerve actively process and analyze visual information, making them extensions of the brain itself.
27
What do colors rods specialize in detecting?
Rods specialize in detecting black, white, and gray colors.
28
How many rods are there in each eye, and what is their function?
There are about 120 million rods in each eye, and they help us see in dim light, especially at night.
29
Where are rods primarily located, and how do they contribute to vision?
Rods are located primarily around the edges of the retina, making them particularly active in peripheral vision.
30
What do cones specialize in detecting?
Cones specialize in detecting fine detail and colors.
31
How many cones are there in each eye, and when do they function best?
There are about 5 million cones in each eye, and they function best in bright light.
32
Where are cones primarily located?
Cones are primarily located in and around the fovea, the central point of the retina.
33
What are cones?
Photoreceptors of the retina sensitive to color. Located primarily in the fovea.
34
What are rods?
Photoreceptors of the retina sensitive to low levels of light. Located around the fovea.
35
What is the fovea?
The central point of the retina
36
What did Margaret Livingstone (2000) discover about the perception of the Mona Lisa's smile, and how do rods and cones play a role?
Livingstone found that the Mona Lisa's smile appears more cheerful when viewers focus on her eyes rather than her mouth.
This effect occurs because the smile's low-detail brush strokes are better perceived by peripheral vision, which relies on rods.
When viewers look directly at her mouth, the smile fades, similar to how a dim star disappears when looked at directly.
37
How is visual information processed as it moves from the retina to the brain, and why is this beneficial?
Visual information from the retina is relayed through the thalamus to the visual cortex in the occipital lobe.
Unlike the principle of contralateral control, each eye sends information to both the left and right hemispheres, allowing both sides of the brain to process visual cues in parallel.
This is beneficial because if one eye is lost, both hemispheres still receive input from the remaining eye.
37
What causes the blind spot in our vision, and how does the visual system compensate for it?
The blind spot is caused by the absence of photoreceptor cells where the optic nerve leaves the retina.
When both eyes are open, the eyes compensate for each other's blind spots.
If only one eye is open, the visual cortex fills in the blind spot with similar patterns from the surrounding areas, allowing us to perceive a continuous image without noticing the hole.
38
What is the blind spot?
A hole in our vision that is created because there are no photoreceptor cells at the place where the optic nerve leaves the retina
39
What are feature detector neurons?
Specialized neurons, located in the visual cortex, that respond to the strength, angles, shapes, edges, and movements of a visual stimulus
40
How do feature detector neurons in the visual cortex contribute to perception, and how do they work together to recognize objects?
Feature detector neurons in the visual cortex respond to different aspects of a visual stimulus, such as strength, angles, shapes, edges, and movements. These neurons work in parallel, each detecting specific features of the object, like lines and color. The information is then compared with stored images in memory, and when many neurons fire together, the brain creates a unified perception of the object, such as recognizing a red square.
41
What did researchers discover about feature detectors and face recognition through the use of transcranial magnetic stimulation (TMS)?
Researchers found that some feature detectors are specialized for recognizing important objects like faces.
When TMS was used to disrupt face recognition areas of the cortex, people were temporarily unable to recognize faces but could still recognize houses, indicating that different areas of the brain are specialized for recognizing different types of objects.
42
How many color variations can the human visual system detect and discriminate among? What are the three primary colors that combine to create all color variations?
The human visual system can detect and discriminate among approximately seven million color variations.
The three primary colors are red, green, and blue.
43
What does the term "hue" refer to in relation to color?
Hue refers to the shade of a color, which is conveyed by the wavelength of light that enters the eye.
44
How do we perceive shorter and longer wavelengths of light?
Shorter wavelengths are perceived as more blue, while longer wavelengths are perceived as more red.
45
What aspect of light determines brightness?
Brightness is determined by the intensity or height of the light wave; bigger or more intense waves are perceived as brighter.
46
What is Hermann von Helmholtz's theory on color perception, and how do the three types of cones function?
Helmholtz theorized that color is perceived due to three types of cones in the retina: one for blue light (short wavelengths), one for green light (medium wavelengths), and one for red light (long wavelengths).
The visual cortex compares the strength of signals from these cones to create the experience of color.
47
According to the Young-Helmholtz trichromatic color theory, what colors does the brain perceive based on the signals received?
The brain perceives purple with primarily red and blue signals, yellow with primarily red and green signals, and white with signals from all three types of cones.
48
What is colour blindness?
The inability to detect green and/or red colours
lack functioning in the red- or green-sensitive cones, leaving them only able to experience either one or two colours
49
What is the opponent-process colour theory?
Proposes that we analyze sensory information not in terms of three colours but rather in three sets of “opponent colours”: red-green, yellow-blue, and white-black
50
What limitation does the trichromatic color theory have regarding the perception of colors like yellow and purple?
The trichromatic color theory cannot explain why yellow does not appear as a mix of red and green, and it does not account for color blindness, as people with color blindness can still see yellow.
51
What is the alternative to the Young-Helmholtz theory, and how does it conceptualize color?
The alternative is the opponent-process color theory, which proposes that we analyze color information in terms of three sets of "opponent colors": red-green, yellow-blue, and white-black.
52
What evidence supports the opponent-process color theory?
Evidence includes the observation that some neurons in the retina and visual cortex are excited by one color (e.g., red) but inhibited by another color (e.g., green).
53
How do the trichromatic and opponent-process mechanisms work together in color vision?
The trichromatic and opponent-process mechanisms work together by having the red, blue, and green cones in the retina respond to light rays at different degrees, sending varying strength signals through the optic nerve. These color signals are then processed by ganglion cells and neurons in the visual cortex, allowing for a comprehensive perception of color.
54
What does the idea of gestalt mean?
A meaningfully organized whole
“whole is more than the sum of its parts.”
55
What are the Gestalt Principles of Form Perception, and can you provide a brief description and example for each?
Figure and Ground: We organize visual input so that we see a figure against a background (e.g., a vase or two faces).
Similarity: Stimuli that are similar are grouped together (e.g., seeing three similar columns of XYX characters instead of four rows).
Proximity: Nearby figures are grouped together (e.g., perceiving four images rather than eight based on proximity).
Continuity: Stimuli are perceived in smooth, continuous patterns (e.g., seeing a line of dots moving smoothly rather than turning abruptly).
Closure: We fill in gaps to perceive a complete object (e.g., seeing a single spherical object rather than unrelated cones).
56
What are binocular depth cues?
Depth cues that are created by retinal image disparity — that is, the space between our eyes — and which thus require the coordination of both eyes
57
What are binocular depth cues, and how do they contribute to depth perception?
Binocular depth cues are created by retinal image disparity, the slight difference between the images projected on each eye due to their spacing. The visual cortex merges these two images into one, allowing us to perceive depth. This principle is utilized in 3D movies, where 3-D glasses create different images for each eye, enabling the perceptual system to transform the disparity into a three-dimensional experience.
58
What is convergence?
The inward turning of our eyes that is required to focus on objects that are less than about 50 feet away from us
59
What is convergence, and how does it function as a binocular depth cue?
Convergence is the inward turning of our eyes required to focus on objects less than about 50 feet away.
The visual cortex uses the angle of convergence to judge the object's distance. When focusing on an object like a finger as it approaches the nose, you can feel your eyes converging. Closing one eye removes this tension, highlighting that convergence is a binocular depth cue that requires both eyes to function effectively.
60
How does accommodation contribute to depth perception?
Accommodation involves the lens changing its curvature to focus on distant or close objects. The information relayed from the muscles attached to the lens helps determine an object's distance. However, accommodation is only effective at short viewing distances, making it useful for tasks like threading a needle or tying shoelaces, but less effective for activities such as driving or playing sports.
61
What are monocular depth cues, and how do they contribute to depth perception?
Monocular depth cues are visual cues that allow us to perceive depth using only one eye. Even with one eye closed, we can still perceive depth. These cues are especially important for judging depth at a distance, providing valuable information about spatial relationships in our environment.
62
What are some important monocular depth cues that help us judge depth at a distance?
Position: Objects higher in our field of vision are perceived as farther away (e.g., fence posts appear farther away as they rise in the picture).
Relative Size: Smaller objects are perceived as farther away if they are assumed to be the same size (e.g., distant cars appear smaller than nearby ones).
Linear Perspective: Parallel lines seem to converge at a distance, helping us gauge depth (e.g., train tracks appearing closer together).
Light and Shadow: Closer objects reflect more light, with normal lighting creating shadows (e.g., shapes appearing extended or indented based on shadowing).
Interposition: When one object overlaps another, the overlapping object is perceived as closer (e.g., a blue star covering a pink bar appears closer than a yellow moon behind it).
Aerial Perspective: Objects that appear hazy or covered in smog seem farther away (e.g., hazy clouds painted to suggest distance).
63
What is the beta effect?
The beta effect refers to the perception of motion that occurs when different images are presented next to each other in succession. The visual cortex fills in the gaps, making it seem as though the object is moving.
64
What is the phi phenomenon?
The phi phenomenon is the perception of motion caused by the appearance and disappearance of objects that are near each other, creating the illusion of a moving zone or cloud around the flashing objects.
65
How do the beta effect and phi phenomenon demonstrate gestalt principles?
Both the beta effect and the phi phenomenon illustrate the gestalt principle by highlighting our tendency to perceive a unified experience, or "more than the sum of the parts," rather than viewing individual elements in isolation.
66
The speedometer in a car has a black background with white numbers, and an orange pointer that indicates the speed at which you are driving. What process explains how your brain sees that orange hand?
a) The left and right cerebral hemispheres employ activation of all four lobes to determine what the eyes have received..
b) The brain compares the visual stimulus to memories and past experiences, and is processed in the hippocampus..
c) The information that travels from your left eye is analyzed by the brain’s occipital lobe, while information from the right eye travels to the parietal lobe..
d) Your brain uses the structures of the limbic system to determine whether parts of the speedometer are symmetrical..
e) Your brain assess the contrast in the light coming from the orange hand and the light coming from the black background.
e)
67
What are sensory modalities?
A type of sense; for example, vision or audition.
68
What is multimodal perception?
The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.
69
What is the effect of integrating unimodal stimuli in perception?
Integrating unimodal stimuli leads to a superadditive effect, where responses to multimodal stimuli are greater than the sum of responses to each modality presented independently, enhancing perceptual experience.
70
What does the superadditive effect of multisensory integration indicate?
It indicates that there are significant advantages and consequences resulting from the integrated processing of multimodal stimuli, enhancing our ability to perceive and understand our environment.
71
What is the superadditive effect of multisensory integration?
The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.
72
What is the Principle of Inverse Effectiveness in multisensory perception?
The Principle of Inverse Effectiveness states that the potential for multisensory enhancement is greater when the unimodal responses are weak.
When one modality (e.g., auditory) provides a strong response, the contribution of other modalities (e.g., visual) is less significant, such as in a noisy environment versus a quiet one.
73
What is the Principle of Inverse Effectiveness?
The finding that, in general, for a multimodal stimulus, if the response to each unimodal component (on its own) is weak, then the opportunity for multisensory enhancement is very large. However, if one component—by itself—is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small.
74
What role do multisensory convergence zones in the brain play in perception?
Multisensory convergence zones, such as the superior temporal sulcus, contain neurons that respond to stimuli from multiple sensory modalities (e.g., visual and auditory).
These zones integrate information from different senses, allowing for enhanced processing and understanding of multimodal stimuli.
75
What is the role of the superior colliculus in multisensory perception?
The superior colliculus is a key multisensory convergence zone that receives inputs from various brain regions involved in unimodal processing of visual and auditory stimuli. It plays a critical role in the "orienting response," allowing individuals to direct their gaze toward the location of a seen or heard stimulus. This involvement is reflected in the presence of multisensory neurons within the superior colliculus.
76
What is the neuron's receptive field?
A neuron’s receptive field is the specific region of space around a perceiver where stimuli can trigger a response in that neuron, causing it to increase or decrease its firing rate.
77
What is neural convergence?
Neural convergence occurs when information from multiple neurons converges on a single neuron, resulting in the third neuron’s receptive field being the combination of the receptive fields of the input neurons.
78
How do multisensory neurons differ from unisensory neurons in terms of receptive fields?
Multisensory neurons have receptive fields that integrate inputs from different sensory modalities, combining the receptive fields of neurons located in various sensory pathways.
79
What is the significance of overlap in crossmodal receptive fields in multisensory neurons?
The overlap in crossmodal receptive fields allows for the integration of stimuli from different modalities that come from the same location in space, leading to enhanced responses in multisensory neurons.
80
How do unimodal receptive fields interact in multisensory neurons?
A multisensory neuron can receive inputs from unimodal neurons, such as one with a visual receptive field and another with an auditory receptive field, that refer to the same spatial locations.
81
What happens when stimuli from separate modalities are processed within overlapping receptive fields?
When information from separate modalities comes from overlapping receptive fields, it is treated as originating from the same location, resulting in a superadditive (enhanced) response from the multisensory neuron.
82
What is the spatial principle of multisensory integration?
The finding that the superadditive effects of multisensory integration are observed when the sources of stimulation are spatially related to one another.
83
What is required for enhancement effects in multisensory neurons regarding the timing of stimuli?
Enhancement effects are observed in multisensory neurons only when inputs from different senses arrive within a short time of one another.
The timing is important because synchronized inputs from different senses can lead to stronger neural responses, enhancing the perception of the combined stimuli.
84
What is the unimodal cortex?
A region of the brain devoted to the processing of information from a single sensory modality.
85
Where have multisensory neurons been observed in the brain?
Multisensory neurons have been observed outside of multisensory convergence zones, in areas once thought to be dedicated to processing a single modality, such as the unimodal cortex.
86
What was the primary visual cortex long thought to be dedicated to?
What notable finding has been made about neurons in the primary visual cortex?
The primary visual cortex was long thought to be dedicated solely to processing visual information, specifically low-level information like edges.
Neurons in the primary visual cortex have been found to receive information from the primary auditory cortex and the superior temporal sulcus, indicating that visual processing is influenced by auditory information.
87
What does the presence of multisensory neurons in the primary visual cortex suggest about sensory processing?
It suggests that sensory processing is integrated early in the cortical stages, meaning that visual information can be influenced by auditory stimuli from the beginning.
88
What are the two potential ways multimodal interactions may occur in the brain?
1) Processing of auditory information in late stages may influence low-level visual processing in unimodal cortex.
2) Areas of unimodal cortex may contact each other directly for multimodal integration.
easier:
"1) Feedback Influence: Auditory processing in later stages might send signals back to influence how visual information is processed at earlier stages. 2) Direct Contact: Areas of the brain that process different senses (like sight and sound) might connect directly to each other, allowing them to work together from the beginning."
89
How might late-stage auditory processing affect visual processing?
What is the alternative explanation for multimodal integration?
Late-stage auditory processing could feedback to influence the low-level processing of visual information in unimodal cortex.
The alternative explanation is that direct contact between unimodal cortex areas facilitates multimodal integration as a fundamental component of all sensory processing.
90
What are multimodal phenomena?
Effects that concern the binding of inputs from multiple sensory modalities.
"Multimodal phenomena refer to stimuli that generate simultaneous (or nearly simultaneous) information across more than one sensory modality."
91
What is crossmodal phenomena?
Effects that concern the influence of the perception of one sensory modality on the perception of another.
92
What is a classic example of a multimodal stimulus?
Speech is a classic example, as it involves sound waves carrying meaningful information and visual patterns from the speaker's lip movements.
93
What is the McGurk effect?
An effect in which conflicting visual and auditory components of a speech stimulus result in an illusory percept.
94
What is the "rubber hand illusion"?
The false perception of a fake hand as belonging to a perceiver, due to multimodal sensory information.
95
How are crossmodal phenomena distinguished from multimodal phenomena?
Crossmodal phenomena are distinguished from multimodal phenomena in that they concern the influence one sensory modality has on the perception of another.
96
What is the ventriloquism effect, and how does it demonstrate crossmodal perception?
The ventriloquism effect is a crossmodal illusion where listeners perceive the origin of speech sounds as coming from a puppet's mouth instead of the ventriloquist's mouth, illustrating how visual cues can influence auditory localization in perception.
97
What is the double flash illusion?
The double flash illusion occurs when a participant sees a single visual flash accompanied by two auditory beeps; they mistakenly report seeing two flashes. This demonstrates that auditory stimuli can significantly influence visual perception by altering how many visual events are perceived.
98
What is the collision illusion, and how does an auditory stimulus affect the perception of visual stimuli in this context?
The collision illusion occurs when two moving circles (or "balls") are perceived as either colliding and bouncing off each other or passing through each other.
Research by Sekuler, Sekuler, and Lau (1997) showed that presenting an auditory stimulus at the time of visual contact significantly influences the perception of a collision, demonstrating how sound can affect the interpretation of ambiguous visual stimuli.
99
What did Rosenblum, Miller, and Sanchez (2007) discover about crossmodal speech effects related to familiarity with a speaker's visual and auditory stimuli?
They found that individuals can become familiar with a speaker's "visual voice" by simply watching them speak, which allows them to recognize the speaker's auditory speech later, even if they had never previously heard that speaker. This demonstrates that familiarity with visual stimuli enhances the recognition of related auditory stimuli.
100
What did studies by Kamachi et al. (2003), Lachs & Pisoni (2004), and Rosenblum et al. (2006) reveal about the relationship between visual and auditory speech perception?
These studies showed that perceivers can identify a speaker's voice by seeing their face while speaking and can also recognize the speaker's visual appearance based on hearing their voice. This suggests that both visual and auditory forms of speech contain complementary information about the speaker's identity.
101
During experiments involving the ______ effect, auditory and visual information conflicted and caused the participant to misinterpret the stimulus.
rubber hand.
McGurk.
multisensory.
double flash.
bouncing balls
McGurk
102
Sumby and Pollack (1954) found that the influence of visual cues on interpretation of an auditory stimulus was ______ when the background noise was loud.
least effective.
least detrimental.
most detrimental.
most effective.
not effective at all.
most effective
103
Match each
Example D: Multi-sensory Perception
Example C: Crossmodal Illusion
Example B: Audio Visualization
Example A: Overriding Modalities
1.
McGurk Effect
2.
Double Flash
3.
Bouncing Balls
4.
Rubber Hand
