Lecture 3 Flashcards
(17 cards)
Sensitivity and roc
Straighter it is the less sensitive it is to stimulus, the more curve the more sensitive
What is roc for someone who is completely insensitive to stimulus like?
Under conservative criteria, when hits are at 0, false alarm is 0.in order to get that 100 dollar. First point false alarm is 0 and hits are 0
Under liberal criteria, 100 percent hit and false alarm. Due to there being 100 dollar at hit
Under 50 hit, 50 false alarm. 50/50 from guessing.
Quiz question
Hits, hyperpolrization, decline in excitary neuro release
Essay
Cross modal/multisensory interaction
Different but similar.
Two senses and how they combine and interact togeather
Not all experiment with two sense are cross modal.
Relative new topic, traditionally one by one.
When senses are put together they change one another.
2008 or later
Peer reviewed
1200 words plus or minus 120 words
You don’t need to summerize the article, focus on one experiment, can allude to others, just summerize one
Question posed
Rational behind
Method
What procedure
Results
Pick one of following, critique, describe a example in everyday life, suggest a application
Conclusion, so what?
See blackboard for how to search…go through the u of t website to ignore journal payment.
Rubric is key. LOOK AT RUBRIC, IT SAYS EVERYTHING! LITERALLY!
Do not quote, paraphrase.
February 9 th is the teach write
120 mil receptor, 1 mil ganglion means?
Convergence, multiple neuron will synapse onto one.
Way more rod than cones, so rod converge more than cones
Retinal ganglion cell
For ex. Need 10 units to fire, light comes in, dim light, interacting with rods to produce activation, 2 unit each because it is dim, but due to convergence, 10 unit is gathers
Cones have less convergence, often 1:1 ratio. Ex. 10 unit of activity, under dim light, the cones are not activated to 10 units, no signal, no detection.
The fact that rods converge mor, explains their increased sensitivity. Eg. Dim light. However it comes with decline visual accurity.
The ganglion just knows there is incoming but does not know wherein is from. No caller Id. No idea who is it from.
Cones have better accurity because of less convergence. Monogous, knows who the call it from. When multiple cones are stimulated, it can recognize its origin, so better procisio
Retinal ganglion cells, receive input from multiple photoreceptors ?”“…….see recur not
The first place in ap is in the retina….. See slide
Where they have a excitary or inhibitory, spends on bipolar cell type. On is on center
Off is off center
In light, photoreceptors are hyper polarized and release less….see slide… On bipolar cells are weird, spontaneously depolarizer in abstance of glutamate. Off hyper polarized in the light, making rgcs less likely to fire, it triggers little activity in the ganglion cells.
Hmmm did it wrong, go back and review.
Lateral inhibition
Signals are sent horizontally by horizontal cells.
Horizontal is for receptor
Amacrine cell is for rgc
Huh?…lateral inhibition…huh?
If light too big?
Signal produced by photoreceptors in the surrounding are passed on the horizontal cells, which inhibits the photoreceptors linked to the response.
A on ganglion cell will maximally fire in the center,
A off ganglion cell will maximally fire in the center of dark
Huh what did she’s say?
Lateral inhibition describes the antagonistic neural interaction between adjacent region of the retina. Activity in one cell will turn off activity elsewhere. This is all for the sake of creating contrast.
Lateral inhibition latera plexus
Sheet of axons transmit lateral inhibition
A is ok
A plus b result in decline in firing rate
Increase in b furthers decrease
Receptor converge onto ganglion. Same branch, increase, other branch, decrease.
Mach band will show this effect
The change in stimulus is a?
The change in intensity is a step function, but our perception is not. Rather due to lateral inhibition. See worksheet.
Perception of this
Result from lateral inhibition, results in increased brightness and dimness at boundary. All of this translates into greater contrast.
Herman grid is another illusion explainable through lateral inhibition.
Simultaneous contrast is the same reason.
Type of rgc
Parasol is big
Midget is small
The receptic field is reflected by their size.
Para usually have more coverage at peripheral
Midget is at fovea.
Only 10 percent is para, 90 percent is midget.
Para transient. Midget, sustained.
Para will fire at transient and only fie transiently. Midget is sustained throughout the stimulus.
Thalamus
Links periphery to cortex
Subcorticle structure, last stop.
Superior colliculus is involved in reflexive orienting to visually salient events. Only 10 of rgc travel directly to superior colliculus, via tectopulvino pathway, mostly by parasol.
Optic chasm
Cross over 50 percent cross over. Cutting it results in huge loss of peripheral vision. Know as bitemporal blindness.
Lgn
Two major component
Two lgm, regulates and organizes information. For every ten impulse that it receives from the retina, it sends 4….see recording. Top down processing
Lauded six layers, bend inner two are m…. See recording…..for rest
