T19_Decision Making

T19_Decision Making

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Unformatted text preview: is also trained to handle stimuli with different directions, speeds, and locations in the visual field. To study sensory processing, the random-dot stimulus is placed in the receptive field of a directionselective neuron. To study decision making, one of the targets that signals the monkey’s commitment to a particular choice is placed in a neuron’s response field. (A) In the variable-duration version of the task, the viewing time is a random value drawn from an exponential distribution. The experimenter controls the duration of motion viewing. The monkey indicates its choice when the fixation point is extinguished. (B) In the response-time (RT) version of the The monkey can respond whenever he is ready Variable viewing duration: behavior 1 % coh “Coherence” 51.2 (aka “dot correlation”) 25.6 0.9 12.8 Probabiliy correct 0.9 6.4 0.8 0.7 3.2 Probability correct A 1 0.8 0.7 0.6 0.6 0.5 0.5 0 200 400 600 Viewing time (msec) F 88.2 Performance on the variable-duration version of the discrimination task depends on motion coherence and viewing time. Solid lines are best-fitting functions based on a model for the decision using signal detection theory. The best fits suggest that the internal signals are proportional to motion strength and viewing time. N = 45,511 trials from 32 experiments in two monkeys. (Reprinted with permission from J. I. Gold and M. N. Shadlen, The influence of behavioral context on the representation of a perceptual decision in developing oculomotor commands. J. Neurosci. 23:632–651. © 2003 by the Society for Neuroscience.) Response time (msec) 900 800 700 600 500 1 B Variable viewing duration: behavior 1 % coh “Coherence” 51.2 (aka “dot correlation”) 25.6 0.9 12.8 Probabiliy correct 0.9 6.4 0.8 0.7 3.2 Probability correct A 1 0.8 0.7 0.6 0.6 0.5 0.5 0 200 400 600 Viewing time (msec) Response time (msec) 900 800 F 88.2 Performance on the variable-duration version of the Perfect performance after 200 msecviewing discrimination task depends on motion coherence and at highest coh 700 time...
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This note was uploaded on 09/08/2013 for the course BBB 217 taught by Professor Nicolerust during the Spring '12 term at UPenn.

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