Brain Structures
What is the main function of the Occipital lobe?
Processing visual information
What is presbyopia? What is myopia?
Presbyopia is the loss of the ability to accommodate, resulting in far-sightedness
Myopia: Nearsightedness, usually genetic but can be developed
In signal detection, what is the difference between a miss and a false alarm?
A miss is when the stimulus is present, but we do not perceive it. A false alarm is when we perceive the stimulus as being present, when it is not.
Do on center off surround cells respond well to homogenous fields of light?
No, the respond best to small spots of light
What is atmospheric perceptive?
Objects that are less clear are often father away. (Often a hazy blue)
Hindbrain
What is the difference in roles between rods and cones in the eye?
Rods are not detail or color sensitive, but sensitive in dim light. Cones are color and detail sensitive, cluster around the center of the eye.
What is just noticeable difference mean in regards to signal detection?
Smallest detectable change in a stimulus
Do on center off surround cells send action potentials to simple cells or complex cells?
Simple cells, which then feeds into complex and hypercomplex cells
How did the Ames room convince your brain that two people that were very different heights, that were actually the same height?
Visual angles and depth cues. An Ames room is not a normal rectangular room, but rather a sloped ceiling with every the angles of every other feature in the house carefully calculated so it gives the illusion when standing in a certain spot.
What is the role of the superior colliculus
Involved in visual reflexes
Define phototransduction
Phototransduction is the conversion of light energy into neural impulses that the brain can understand
What is absolute threshold?
The smallest stimulus you can detect 50% of the time
Describe the different types of color blindness/deficiency we discussed in class.
Dichromats only have 2 cone responses and monochromats have one cone type and cannot distinguish between color.
What does the oculomotor cue "accommodation" mean?
The lens changes shape to focus on an object of interest on the retina
This part of the brain is like a relay station from the spinal cord to the rest of the brain. It also controls some reflexes such as swallowing and coughing.
The medulla
What is the blind spot? Why don't we notice our blind spot?
The blind spot is the location where axons from ganglion cells (axons make up the optic nerve) leave the back of the eye, so there are no light receptors.
We don’t notice it because items of interest fall of the fovea, and we use top-down information to fill in the missing pieces.
From what we learned about the methodology for studying thresholds, what is the method of constant stimuli?
A set of stimuli are presented in random order. Most accurate but time consuming.
Identify and describe the major properties/functions of each of the following parts of the eye: cornea, lens, retina, fovea, pupil, and iris.
Cornea: transparent, protective outer covering
Lens: Flexible tissue that helps focus light on the retina
Retina: A thin layer of tissue at the back of the eye that contains rods and cones
Fovea: The central part of the retina, where cones cluster
Pupil: A hold in the center of the eye that allows light to enter
Iris: A muscle that expands and contracts to change the size of the pupil
What monocular cue describes parallel lines converging as distance increases
Linear Perspective
What brain structure is involved in arousal and other autonomic functions
The reticular formation
Explain the trichromatic theory.
We have three types of cones that are maximally sensitive to one range of wavelengths of light. Colors sensed by comparing the amount of activation.
What is Weber's law?
The larger the stimulus, the bigger the change needs to be to notice a difference.
Do we have a grandmother cell? Provide an argument for each side.
We might have a grandmother cell because it appears that we have neurons for processing highly specific visual information
We probably don’t because we don’t have enough cells and it’s an inefficient way to store information
What is the inverse projection problem? How does our brain solve it?
We have a 2D image in our retina that we need to convert to a 3D object. We use oculomotor cues and top down information to fill in the gaps and make our best guess.