Vision & Hearing Flashcards
What is sensation?
Registration of physical stimuli from the environment by the sensory organs
What is perception?
subjective interpretation of sensations by the brain
What do sensory receptors do?
convert sensory energy into neural activity
What are receptive fields?
Region of sensory space in which a stimulus modifies a receptor’s activity
Are sensory receptors evenly distributed across the body?
no
Why are your fingers more sensitive than your elbows?
sensory density is higher in figners
What is a topographic map?
neural spatial representation of the body or areas of the sensory world perceived by the sensory organs
How is info passed from visual receptors to brain?
visual receptors to thalamus to cerebral cortex
How is info passed from auditory receptors to brain?
auditory receptors to hindbrain to midbrain to thalamus to cerebral cortex
How is info passed from somatosensory receptors to brain?
somatosensory receptors to spinal cord to brainstem to thalamus to cerebral cortex
What is the cornea?
clear outer layer of eye
What is the function of the iris?
opens and closes to let more or less light into the pupil
What is the function of the lens?
focuses light
What is the function of the retina?
converts light to neural signals
What is the fovea?
small depression in the center of the retina where there is only cones (highest visual acuity)
What is the blind spot?
the optic disc, where the optic nerve connects to eyes, no receptors
What are the types of photoreceptors?
cones and rods
What are some traits of rods?
work well in dim lighting, lower visual acuity, colour blind more in periphery
What are some traits of cones?
do not work in dim light, higher visual acuity, colour sensitive, more in center
What are the types of neurons in the retina?
bipolar cell, horizontal cell, amacrine cell, retinal ganglion cell
What are two types of retinal ganglion cells? (RGC)
magnocellular cell and parvocellular cell
What is the function of M-cell?
receives input mostly from rods, sensitive to light/moving stimuli
What is the function of P-cell?
receives input mostly from cones, sensitive to colour
What is the optic chiasm?
where optic nerves from each eye cross, axons from the inside (nasal) half of the retina will cross to other side, axons from the outside (temporal) will stay on same side
Info from the left side of the visual field goes where? What about right side?
left goes to right side of brain, right goes to left side of brain