Anatomy/Methodology
Light, Eye, Retina
LGN, V1, Edges
Color
Motion
50
List first-order edges and second-order edges.
First-order: Luminance edges and Hue edges.
Second-order: Texture edges, Motion edges, Depth edges.
50
Why is dim-light vision generally lacking color?
Dim light is only able to stimulate rods. Rods contain only one type of photopigment molecule: rhodopsin. Rods are not able to support varied activity in response to different wavelengths.
100
The primary function of each lobe.
Frontal: planning and action, executive function
Parietal: sensory information
Occipital: vision
Temporal: audition
100
The difference between additive and subtractive color mixing.
Additive: mixing light, adding emitted color, RGB
Subtractive: mixing paint, every new color subtracts absorbed color, CyMY
100
If Prof. Holbrook can reliably read more letters on the Snellen chart than me, he has greater _____.
Visual Acuity.
100
Due to _____ in Color Vision, after viewing the following images, the afterimage will include which colors?
Color Opponent-Process. Black, Green, and Yellow.
100
A critical addition to motion detector circuits, allowing them to activate despite timing differences between activation of neurons with adjacent receptive fields.
What is a delay?
200
The type of processing used to perceive this image as a person. 
Global (holistic) processing.
200
Rods have ____ convergence, whereas cones have _____ convergence. How does this affect spatial resolution?
high; low
rods have low spatial resolution, but are sensitive to motion
cones have high spatial resolution
200
V1's mapping of the world exhibits which two organizational features? The LGN's mapping of the world exhibits one of these features, which one?
V1: Topographical Mapping, and Cortical Magnification
LGN: Topographical Mapping.
200
Color opponent signals are mainly found in the _____ cells.
Parvocellular Layers in the LGN. M- and L-cone cells.
S-cones go through the koniocellular layers.
200
The motion perceived when the location of an object at time point one is correlated with the location of another object at time point two, despite nothing truly moving.
What is apparent motion?
300
This subcortical structure is associated with sensory processing.
Thalamus
300
With respect to the retina, lateral inhibition refers to
Antagonistic neural interaction between adjacent regions in the retina
300
What are the axes for the Contrast Sensitivity Function? What is its general shape? And what information does it communicate to us?
1. X: Spatial Frequency (cycles/degree). Y-right: Contrast Threshold (the smallest amount of contrast required to detect a pattern, in %). Y-left: the reciprocal of the Y-right.
2. An upside down U shape
3. That any (spatial frequency by contrast threshold) under the line is a visible pattern to the viewer. Any combination above the line is not a visible pattern.
The limits of seeing a pattern depends on spatial frequency and contrast.
300
What are people doing differently when processing the blue-and-gold dress that causes different perceptions across people? (Note: this may not be the only explanation for the blue-and-gold dress illusion).
They are making different assumptions about the type of light illuminating the dress.
300
This type of motion is perceived due to changes in contrast or texture despite nothing truly moving.
Second-order motion.
400
The difference between Fechner's law and Steven's law.
Fechner: as intensity increases, larger changes are needed to produce subjectively noticeable differences
Steven's: Accounts for variability between different sensations
400
Draw/describe the receptive field of a ganglion cell. Describe it, and discuss how the cell would respond to different spots of light.
center-on/surround-off or center-off/surround-on
400
While participating in a line orientation perception study, I was able to reliably report a line with 0 degree offset was different than a line with 5 degree offset. However, I was not able to reliably report that a line with 0 degree offset was different than a line with .75 degree offset.
What do the limits of my perceptual ability tell us about the organization of V1?
That different line orientations are represented by columns in V1. However, there are not enough columns V1 to represent each possible degree of offset (physically infinite).
400
What is the Ishihara test, what does it do, and what does it tell you?
The Ishihara test is a test for red-green deficiency.
It presents different plates to participants: circles filled in with dots.
The only cue is color, and they need to tell what number is embedded.
If a participant is red-green colorblind, there will be some plates which the color cannot cue the embedded number.
They cannot differentiate the two colors.
Usually due to deuteranopia: problem with M-cone
400
Allows for the temporal integration of quickly presented visual stimuli.
What is Visible Persistence? Sustained activation after the stimulus is removed.
500
We want to study the time course of activation in the brain as it travels from the thalamus to V1 to higher-order visual areas.
For our first study, we want to measure the timing of activations across large areas of the brain, and aren't as interested in the locations of activation. What brain imaging method should we consider and why?
For a follow up study, we want to measure the location of activations with very high resolution, but aren't as interested in the exact timing of activation. What brain imaging method should we consider and why?
Initial study: Electroencephalograph (EEG). Low spatial resolution but high temporal resolution.
Follow-up study: Functional magnetic resonance imaging (fMRI). High spatial resolution, but low temporal resolution.
500
Describe the functions of each part of the following parts of the eye: pupil, cornea, lens, retina
.
Pupil: controls the amount of light that enters the eye
Cornea: most of the focusing (80%) with a fixed shape; controls and focuses the entry of the light by bending or refracting the light onto the lens
Lens: focuses the eye (20%); converges focusing onto the retina depending on distance of object; flexible.
Retina: receives light the lens focuses and sends the retinal image to the optic nerve and to the brain.
500
What is a Fourier Analysis? Explain how the visual system could compute a Fourier Analysis of the visual scene. Reference a particular feature of the visual system (neurophysiology, in terms of representation, etc) that could support a Fourier Analysis.
Fourier Analysis: Decomposing a complex wave into its component simple sine waves.
Given that retinal ganglion cells, and V1 simple cells, have inhibitory and excitatory regions, they could act as filters for particular sine-wave gratings. Such that, a given cell only activates when exposed to one particular sine-wave structure. If we have cells for all wavelengths and phase of a sine-wave, then a complex visual scene can be broken down into component sine-wave gratings.
500
Describe how a categorical perception of color could affect our color perception:
Putting objects into categories changes how they are perceived.
Differences within a category minimized.
Differences between categories enhanced.
Language influences the categories chosen/available.
Wavelength is a continuous measure, this continuous sensory data is binned into categories.
500
While you are moving forward, objects in the visual scene move away from this point.
The Focus of Expansion.