LECTURE 2 Flashcards
What are the two types of cells in the brain?
Neurons and glial cells.
What percentage of the brain’s cells are neurons?
10
What is the main function of glial cells?
Support and less direct involvement in information processing.
What do neurons have that is unique to them?
Dendritic arbor and a long axon.
What happens at the axon hillock when a neuron depolarizes enough?
An action potential is triggered.
What causes depolarization in a neuron?
Sodium ions entering through ion channels.
What are nodes of Ranvier?
Gaps between myelin sheaths on axons.
What happens at a synapse?
Neurotransmitters are released and can excite or inhibit the next neuron.
What are the two main types of visual receptor cells in the retina
Cones and rods.
Where are cones mostly located?
In the fovea
Where are rods primarily located?
In the periphery of the retina.
What is the main function of cones?
Color and detail perception.
What is the main function of rods?
Vision in dim light.
What is the pathway from the retina to the visual cortex?
Retina → Lateral Geniculate Nucleus → Striate Cortex (V1).
What visual function is associated with V4?
Color and shape perception.
What is the main function of V5 (MT in humans)?
Motion perception.
What is the dorsal stream also known as?
The “where” pathway.
What is the ventral stream also known as?
The “what” pathway.
What type of coding does the dorsal stream use?
Egocentric (body-centered) coding
What type of coding does the ventral stream use?
Allocentric (object-centered) coding.
What is the Müller–Lyer illusion used to study?
The difference between vision-for-perception and vision-for-action system
What is stereopsis?
Depth perception based on binocular disparity.
What does the Ames room demonstrate?
The effect of depth cues on perceived size.
What is size constancy?
Perceived size remains constant despite changes in retinal image size.
What is the binding problem?
How the brain integrates different visual features into a cohesive perception.
What is color constancy?
Perceived color remains stable despite changes in lightin
What is blindsight?
The ability to respond to visual stimuli without conscious awareness.
What are the two types of blindsight?
Type-1 (no awareness) and Type-2 (some residual awareness).
What does the perception-action model explain?
The interaction between dorsal and ventral visual streams in tasks.
Which cells leave the eye and synapse in the lateral geniculate nucleus (LGN)?
Retinal ganglion cells.
What is the correct ascending visual hierarchy?
Eye > Geniculate Nucleus > Striate Cortex > Extrastriate Cortex.
What does the ventral stream process?
Vision-for-perception, object-centered coding, and sustained representations.
What does the dorsal stream process?
Vision-for-action, body-centered coding, and short-lived representations.
What is chromatic adaptation?
Sensitivity to the light source of a color decreases over time.
What does the Retinex theory suggest?
Color perception involves comparing light reflected from adjacent surfaces.
What does motion parallax describe?
Movement in one part of the retinal image relative to another to infer depth
How is depth information combined from multiple cues?
Through additivity, selection, or weighting of more reliable cues.
What is subliminal perception?
Ability to process stimuli below conscious awareness.
What does the Ebbinghaus illusion demonstrate?
Context affects the perceived size of an object.
What is the function of retinal ganglion cells?
Transmitting signals from cones or rods to the brain.
