psyc 375 chapter 9

sensation

sensory information is detected by a sensory receptor which is specialized neuron that respons to a specific stimulus

perception

the way sensory information is organized, interpreted, and consciously experienced

sensory recpetors key variables

receptive fields, receptor density, and receptor sensitivity

rods

specialized to function in low light levels, sensitive to lumiance, longer, cylindrical outer segment, more numerous

cones

specialized for colour and high visual acuity, sensitive to particular wavelengths of light, tapered outer segment, 1 of 3 pigments

s cone

small wavelenght, 419, blue- fewer

m cone

medium wavelength, 531, green

L cone

long wavelength, 539, red

fovea

only cones

M cell

RGC, recieves input from rods, sensitve to light and moving stimuli

P cell

RGC, recieves input from cones, sensotve to colour and fine detail

dorsal stream

“how” pathway, vision for action, unconcious

ventral stream

“what” pathway , vision for identification, conscious

visual form agnosia

damage to ventral stream, can’t percieve pbjects

optic ataxia

damage to dorsal stream, deficit in visual control of reaching and other movements