Topic 3 Perception pt 2 Flashcards
true or false: the proximal stimulus is measured on an absolute scale
false: the proximal stimulus is measured on a relative scale. For example, we don’t measure how much light enters the photoreceptors- we instead measure how much light enters the photoreceptors relative to the other photoreceptors
what is a blind spot, and what causes it
A blind spot is the area in the retina whereby there are no photoreceptors due to the axons passing over the front of the retina (there is simply no room for the photoreceptors because of the axons)
the sensitivity of the visual system depends on the _______
the sensitivity of the visual system depends on the ambient light levels
Jack is in a dark room and then turns on the flashlight. In another room, Jill is in a well lit room and turns on the flashlight. Who will experience an increase in firing rate in their visual cortex?
Jack, because he is in the darker room
What variable is the Weber fraction?
K
higher order neurons have _____ receptive fields
higher order neurons have larger receptive fields and respond to more complex stimuli
receptive fields
area of sensory surface to which a neuron responds
perceptual resolution and acuity are ____ related to sensory receptive field size
perceptual resolution and acuity are inversely related to sensory receptive field size
higher order neurons have _____ receptive fields and ______ acuity
higher order neurons have larger receptive fields and lower acuity
respond to more complex stimuli
higher order neuron
what happens to the firing rate when light shines on the on center of the ganglion cell receptive field
on center = fires more when there is more light in the center
what happens to the firing rate when light shines on the off center of the ganglion cell receptive field
off center = fires below baseline due to inhibitory input
what will happen if we shine a light on the entire receptive field of the ganglion cell?
slight increase in firing rate
what happens if we shine a light on the surround ?
decrease in firing rate
what happens if we shine a light outside the receptive field
no change in baseline firing rate
receptive field of a hair cell is based on
frequency of the sound
what happens to the sizes of the cones as you get further away from the fovea? what happens to the spacing?
the size of the cones get bigger, and have larger receptive fields, and therefore have lower acuity. The cones are also more spaced apart
explain integration of light in retina
photoreceptors feed information to bipolar cells and then the single ganglion cells. A single retinal ganglion cells is receiving input from a large number of photoreceptors. The receptive field for the retinal ganglion cell is equal to the receptive field of all the combined photoreceptors
receptive field of a mechanoreceptor
area on the skin
Spatial organization (____) of sensory surface is preserved and projected onto the ______
Spatial rganization (topography) of sensory surface is preserved and projected onto the primary sensory cortex
cortical magnification
the area in the cortex is proportional to density of sensory receptors and inversely related to the receptive field size
tonotopic map relies on
frequency (tone = frequency)
topographic map for taste is based on
taste quality (sweet, salty , sour)
cortical reorganization
changes in topographical map
true or false: lower order sensory neurons are closer to the sensory receptors
true
how does processing occur as information travels from lower order neurons to higher order neurons
processing proceeds serially (sequentially), parallel (simultaneously), and is recurrent (loops)
recurrent= arrows are double ended and bidirectional
tertiary visual cortex is the same as _____
visual association cortex (MST, LIP)
multimodal association cortex
VIP
Why is V1 the same as striated cortex?
alternation between left and right eye visual field gives it a stripes pattern
blobs
unit of cells in the cortical columns (V1) are interested in colors. Mixed in the orientation process, we are also interested in the color
explain the more complex feature detector of length
we have feature detectors for oriented lines of a specific length which have excitation and inhibitory areas.
What is the function of having feature detectors for length and orientation
Once you can detect lines at a particular length of a particular orientation, you can combine these detections and eventually make out a shape (can detect angles)
What happens if you have bilateral damage to V5?
loss of motion perception and everything looks still and you see things in snippets of images
what is the feature detector for where sounds are coming from
superior colliculus: sound helps guide the eye
interaural time delay
difference in arrival sound of the 2 ears. Detecting this allows to infer where the sound is coming from
we know where sound is coming from based on _______ detectors
coincidence detectors
heirarchy in the somatosensory system (primary, secondary, tertiary, multimodal) are found primarly in the ____ lobe
parietal lobe
what are more complex feature detectors
in the somatosensory cortex for the hands, there are motion sensitive neurons, orientation sensitive neurons, and direction sensitive neurons
