Visual System Flashcards
What is the difference between bottom-up and top-down processing in visual perception?
Bottom-up: Data-driven using sensory information to piece together the image. Top-down: Conceptually-driven
What is synesthesia?
Synesthesia is the blending of senses where stimulation in one modality produces a sensation in a different modality (e.g. seeing colors when reading letters).
What is the law of specific nerve energies?
It states that the brain interprets activity in specific sensory neurons as representing a particular type of sensory information even if the stimulus doesn’t physically resemble it.
What happens at the optic chiasm?
At the optic chiasm half of the axons from each optic nerve cross to the opposite side of the brain
What is the function of the fovea?
The fovea is the area in the retina with the highest visual acuity responsible for sharp
What is lateral inhibition in the visual system?
Lateral inhibition is a process where activation of one set of photoreceptors inhibits neighboring photoreceptors enhancing contrast at edges of objects.
What is the difference between the parvocellular and magnocellular systems in visual processing?
Parvocellular: Specializes in color and fine detail perception (small receptive fields). Magnocellular: Specializes in motion and overall patterns (larger receptive fields).
What is blindsight?
Blindsight is the ability to respond to visual stimuli without conscious perception usually following damage to the primary visual cortex (V1).
What are the two primary visual streams?
Ventral stream: The “what” pathway responsible for object recognition. Dorsal stream: The “where/how” pathway
What is visual agnosia?
Visual agnosia is the inability to recognize or identify objects typically caused by damage to the ventral stream of the visual cortex.
What is a receptive field in visual processing?
A receptive field is the area of the visual field that excites or inhibits a visual neuron depending on factors like light location
What are rods and cones in the visual system?
Rods: Sensitive to faint light, more numerous in peripheral retina, responsible for night vision. Cones: Sensitive to bright light, concentrated in the fovea, responsible for sharp and color vision.
