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94 Cards in this Set
- Front
- Back
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What is Sensation? |
The ability to detect a stimulus, and perhaps, to turn that detection into a private experience. |
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What is Perception? |
The act of giving meaning to a detected sensation. Example: Whether you think music is good or not. |
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What is total blindness? |
No light sensation. |
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What is Psychophysics? |
Refers to the science of defining quantitative relationships between physical and and psychological events |
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Who invented psychophysics and is sometimes considered the "True Founder" of Experimental Psychology? |
Gustav Fechner |
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What is Panpsychism? |
The idea that the mind exists as a property of all matter. That is, - all matters have consciousness. |
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What are the three ways of studying Psychophysics? |
1) Threshold 2) Magnitude Estimation 3) Neuroscience |
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What are the four Threshold Methods? |
1) Two-Point Threshold 2) Difference Threshold 3) Absolute Threshold 4) Signal Detection Theory |
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What is Magnitude Estimation? |
Assigning value to the sensory experience |
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What are the two methods of Neuroscience? |
1) Electrophysiology 2) Brain Imaging |
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What is the Two-Point Touch Threshold? |
The minimum distance at which two stimuli can be distinguished. |
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What is the Just Noticeable Difference (JND)? |
The smallest detectable difference between two stimuli, or the minimum change in a stimulus that can be correctly judged as different from a reference stimulus. Also known as the Difference Threshold. JND = (Standard Value)(K) |
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Who did the math and who did the observation? |
Weber's Observation and Fechner's Math |
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How does the magnitude of subjective sensation increase? |
Proportional to the logarithm of stimulus intensity. |
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What is Magnitude Estimation? |
Simply asking subjects to rate an experience. |
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What is Cross-Modality Matching? |
Subs are asked to match perceived magnitude of a stimulus in one sensory domain with the perceived magnitude of a stimulus from another domain. |
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What is Signal Detection Theory? |
A psychophysical theory that quantifies the response of an observer to a sensory signal in the presence of noise. |
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The Four Responses of Signal Detection Theory? |
Hit, Miss, False Alarm, Correct Rejection |
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What is Sensitivity or Discriminability? |
Value that defines the ease with which an observer can tell the difference between the presence and absence of a stimulus or the difference between Stim 1 & Stim 2. Depends on Physiology. |
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What is Criterion or Bias? |
An internal threshold that is set by the observer. If the Internal Response is above Criterion we say, "Yes I hear that." Depends on your Psychology. |
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What is Fourier Analysis? |
Mathematical Procedure by which any signal can be separated into a component of sine waves at different frequencies. Combining these component sine waves will reproduce the original signal. |
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What is a Sine Wave? |
1) In hearing, a waveform for which variation as a function of time is a sine function. Also called "pure tone". 2) In vision, a pattern for which variation in a property, like brightness or color as a function of space, is a Sine Function |
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What is a Period or Wavelength? |
The time or space required for one cycle of a repeating waveform. |
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What is a Phase? |
In vision, the relative position of a grating. In hearing, the relative timing of a sine wave. |
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What is Amplitude? |
Height of Sine Wave, from peak to trough, indicating the amount of energy in the signal. |
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What are Sounds? |
Changes in pressure over time. |
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How wide is your Visual Field? |
170 Degrees |
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How can we describe Images? |
Changes in light and dark across space. In the case of Sine Waves, these would look like bars of light & dark - gratings. |
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How many degrees is your thumbnail at arm's length? |
2 Degrees |
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What is Cycles per Degree? |
The number of pairs of dark and bright bars per degree of visual angle |
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What do we have Low Sensitivity to? |
Low Spatial Frequencies and High Spatial Frequencies. |
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How is Spatial Frequency described? |
As Cycles/Degree. The number of changes across 1 degree of a person's visual field |
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What is the maximum sensitivity? |
6 cycles/degree of visual angle |
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When a face is 1 meter away and therefore takes up 10 degrees, what is the Peak Sensitivity? |
6 c/d * 10 d/i = 60 cycles/image. Woman. |
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When a face is 6 meters away and therefore only takes up 2 degrees, what is the Peak Sensitivity? |
6 c/d * 2 d/i = 12 cycles/image. Angry man. |
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What is the distance of switch a function of? |
Image Size & Cut-Off Frequencies for the Individual Image |
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What three things are needed to perceive an image? |
Physics, Biology, and Psychology |
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What is Spatial Vision? |
Scientifically, it is the visual ability to resolve or discriminate features? |
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How do vision scientists measure the size of Visual Stimuli? |
By how large an image appears on the retina rather than by how large the object is. |
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How do we measure Retinal Size? |
Degrees of Visual Angle |
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The visual angle is a function of what? |
Both its actual size and distance |
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What is Light? |
A narrow band of electromagnetic radiation that can be conceptualized as a wave or stream of photons. |
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What is Optics? |
The study of interaction between light & matter. |
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What do Optical Illusions do? |
Manipulate the interaction in some way. |
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What happens to light in the atmosphere? |
Light is absorbed or scattered and never reaches the perceiver. |
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What is the Cornea? |
Transparent "window" into the eyeball |
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What is the Aqueous Humor? |
The watery fluid in the anterior chamber |
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What is the Crystalline Lens? |
The lens inside the eye, which allows changing focus |
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What is the Pupil? |
The dark circular opening at the center of the iris in the eye, where light enters the eye |
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What is the Iris? |
The colored part of the eye, consisting of a muscular diaphragm surrounding the pupil and regulating the light entering the eye by expanding and contracting the pupil |
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What is the Vitreous Humor? |
The transparent fluid that fills the large chamber in the posterior part of the eye |
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What is the Retina? |
A light-sensitive membrane in the back of the eye that contains rods and cones, which receive an image from the lens and send it to the brain through the optic nerve. |
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What is refraction in the eye used for? |
Necessary to focus light rays onto Retina. This is accomplished with the Lens. |
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What is Accommodation? |
The process in which Lens changes its shape, thus altering its refractive power. |
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What is Emmetropia? |
Happy condition of no refractive error. |
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What is Myopia? |
When light entering the eye is focused in front of the Retina, and distant objects cannot be seen sharply. Nearsightedness. |
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What is Hyperopia? |
When light entering the eye is focused behind the Retina. Farsightedness. |
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What is an Astigmatism? |
Visual defect caused by the unequal curving of one or more refractive surfaces of the eye, usually the Cornea |
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What is the Fundus? |
The back surface of the eye |
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What are Photoreceptors? |
Cells in the retina that initially transduce light energy into neural energy |
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How many rods and cones do we have? |
90 million rods and 10 million cones |
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Why do you have poor color vision in your periphery? |
Because there are so few cones there. |
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Photoreceptor Type in Fovea and Periphery |
Cones and Rods |
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Bipolar Cell Type in Fovea and Periphery |
Midget and Diffuse |
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Convergence in Fovea and Periphery |
Low and High |
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Receptive Field Size in Fovea and Periphery |
Small and Large |
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Acuity (Detail) in Fovea and Periphery |
High and Low |
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Light Sensitivity in Fovea and Periphery |
Low and High |
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What is Age-Related Macular Degeneration? |
Disease associated with aging that affects the macula. Gradually destroys sharp central vision. Results in a Scotoma |
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All about P-Ganglion Cells |
Connect to Parvocellular Pathway (Small). Therefore also connected to Midget Bipolar Cells, which are connected to cones. Therefore P-Ganglion cells are involved in fine visual acuity, color, and shape processing. Poor temporal resolution but good spatial resolution. |
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All about M-Ganglion Cells |
Connection to Magnocellular Pathway (Large). Involved in Motion Processing. Excellent temporal resolution but poor spatial resolution. |
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What are Mach Bands? |
Illusory stripes that emphasize differences in luminance. Stripes are a product of visual system's center-surround receptive fields. |
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What is a Ganglion Receptive Field? |
An area of the retina in which light must fall for the neuron to increase or decrease its firing rate |
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What are Retinal Ganglion Cells *most* sensitive to? |
*Differences* in the intensity of light between Center & Surround & are relatively unaffected by average intensity. |
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How do Center-Surround Receptive Fields emphasize boundaries? |
Because luminance variations tend to be smooth within objects and sharp between objects. |
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Where is the What Pathway and what does it analyze? |
From Occipital Cortex to Temporal Lobe. Form and Color. |
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What does the Where Pathway analyze? |
Motion and Spatial Relations |
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Two important features of Striate Cortex |
Topographical Mapping - It receives the ordered projection of the image from the retina. Cortical Magnification - Dramatic scaling of information from different parts of the visual field. |
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Visual Crowding |
The deleterious effect of clutter on peripheral object detection |
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What is the major transformation of visual information that takes place in the Striate Cortex? |
Circular receptive fields found in retina and LGN are replaced with elongated "stripe" receptive fields |
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Simple Cells in Striate Cortex |
Some prefer bars of light, some prefer bars of dark |
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Complex Cells in Striate Cortex |
Respond both to bars of light and dark |
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What is Orientation Tuning? |
Tendency of neurons in striate cortex to respond most to bars of certain orientations |
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How are the circular receptive fields of the LGN transformed into the elongated receptive fields of the Striate Cortex? |
Hubel & Wiesel. Very simple. If you string several retinal ganglion cells together, they form a bar. |
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What do cortical cells respond especially well to? |
Moving lines, bars, edges, gratings (certain frequencies and orientations), certain motion directions. They function like a filter because of how specifically they respond. |
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What is adaptation? |
A reduction in response caused by prior or continuing stimulation. |
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What is Tilt Aftereffect? |
The perceptual illusion of tilt, produced by adapting to a pattern of a given orientation |
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What is Agnosia? |
Damage to the inferotemporal area; cannot recognize familiar objects. But do show implicit knowledge for the item. |
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Evidence Facial Processing is Special: |
Prosopagnosia, FFA, Holistic Processing of human faces, inverted faces |
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Evidence Facial Processing is Not Special |
Greeble Study |
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Holistic Processing |
Processing that involves integrating info from an entire object. |
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What are the Gestalt Principles? |
The perceptual sum is greater than the sensory parts. 1) Proximity 2) Similarity 3) Good continuation 4) Occlusion 5) Closure 6) Common fate 7) Figure-ground Segregation |
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How do we determine which is Figure and which is Ground? |
Surroundedness, Size, Symmetry, Parallelism, Extremal Edges, Relative Motion |
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Synesthesia |
Senses are crossed. |
