Visual Perception Flashcards
Perception
Stimulus interpretation
Two types of photoreceptors
Rods and Cones
Cones
Cones are sensitive to higher levels of light (color perception)
Vision Processing Process
Stimulus - Receptor (Rods & Cones)- Pathway to
Brain (Optic Nerve, Chiasim, LGN) - Processing (V1)
Cones are named for their wavelength range of sensitivityIn most humans, 3 types (“trichromatic”)
Rods
Rods are sensitive to low levels of light
Three types of cones
Short, Medium, and Long Wavelengths.
Each person’s trichromacy is different.
Fovea
A small depression within the neurosensory retina where visual acuity is the highest.
A dense batch of cones where vision color acuity is better
Optic Blindspot
Blindspot in Feild of vision
Receptive Field
Region that receives and responds to input/stimulus. (Think about overlapping bullseye ring, the center is the fovea)
Retina
Where light receptive cells are found
Optic Nerve
How information leaves the eye
Optic chiasm
Axons in the nasal retina cross from one side of the brain to the other
Temporal Retina
Temporal field of vision
Nasal Retina
Medial field of vision
Lateral geniculate nucleus (LGN)
Transmits visual information to the Primary Visual Cortex (V1)
Primary Visual Cortex (V1)
Visual Processing
Properties of V1
Retinotopic
Foveal Magnification
Retinotopic
Map visual input from the retina to neurons
What are the two Visual Processing Streams?
Dorsal and Ventral
Dorsal Visual Stream
“Where” processing.
V1 - V2 - V3 - Area 5/MT - MST - Paretal lobe
Ventral Visual Stream
“What” processing.
V1 - V2 - V4 - Inferotemporal Cortex
How does a single complex neuron know to recognize something?
Complex neurons respond to the combination firing of other neurons
