Lec 4 Sensation and Perception Flashcards
Define perception:
Stimulus from the environment activates sense organs, input is transduced into neural activity and sent to brain for processing
Define sensation:
Early processing. The ability to capture external stimulus and convert it to electrical signals.
Each sensory system begins with what?
structure for collecting, filtering and amplifying information
What is the thickness of the retina?
0.5mm
What are photopigments?
Protein molecules that are sensetive to light
Photoreceptors, rods and cones, contain what?
Photopigments
What are the three types of cones?
Short wave length cones (blue), medium wave length cones (greenish), long wave length cones (red)
What is rhodopsin?
a photopigment found in rods that destabilize in low levels of light
What is photopsin?
a photopigment found in cones that respond to intense levels of light and can replenish rapidly.
Where are cones and rods?
Cones are closely packed toward the fovea (centre) whereas rods are distributed evenly across the retina
Which hemisphere does the right visual field go to?
Left
Which hemisphere does the left visual field go to?
Right
90% of the axons in the optic nerve follow the retinogeniculate pathway to the what?
Lateral geniculate nucleus (LGN) of the thalamus
10% of the optic nerve fibers go to…?
Pulvinar nucleus of the thalamus and superior colliculus of the mid brain
Superior colliculus and pulvinar nucleus play a role in…?
Visual attention!
