BUONOMANO, Time Perception, UCLA, Sept 14, 2018
<p class="MsoNormal" >BUONOMANO, Time Perception, UCLA, Sept 14, 2018</p>
<p>
this is a seminar in the Stanford CEC Center on the Nature of Time;
this is Friday at 10:40AM in Cordura Hall.</p>
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brain's ability to address time over 12 orders of magnitude.</p>
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1 msec at shortest.</p>
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many temporal distortions and illusions.</p>
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expanded circle seems longer (relative to constant circles) in this illusion.</p>
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how does the brain tell time? is there a master clock?</p>
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all depend on oscillators. eg swing of pendulum; (but brain has no counter)</p>
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Circadian clock....</p>
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DNA transcribes protein and it inhibits itself... and that takes 24 hours...
uses phase of oscillation (but no counter)</p>
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most animals have circadian clocks... even bacteria...</p>
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shows 23 hour mutant versus 30 hour mutant.</p>
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each thrive best in their appropriate circadian environment.</p>
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any dynamical system can be used as a clock (Einstein)</p>
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shows chain of neurons used as a clock... creating a neural state space.</p>
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eg from Zebra finch... HVC... a songbird... must have good timing...</p>
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chain of neurons fires over a second;</p>
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similar in OFC in mouse...</p>
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mouse detects an odor and 3.5 seconds later gets a reward and it anticipates the reward.</p>
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can use a NN to decode the elapsed time of neural dynamics.
or might be a trajectory
striatal neurons have rhythms and a clock as does OFC pyramidal neurons.</p>
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but how are they used... and what causes what?</p>
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we now have models of dynamical systems...</p>
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RNN with sigmoid activation functions.</p>
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but don't want them to be chaotic.</p>
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want high repeatability....</p>
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shows RNN being read off by two neurons.</p>
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hypothesis: dynamic attractors....</p>
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memory might be a dynamic pattern.</p>
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cortical circuits in vitro... in slice.</p>
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shows neurons that respond at eg 200 msec.</p>
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work of Goel in his lab 2016.</p>
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topic four: presentism (local)</p>
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versus block Universe... eternalism.</p>
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Why is eternalism preferred in physics and philosophy.</p>
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he shows usual special relativity illustrations of moving reference frames
(bullets being fired on a train)</p>
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bullets going 2/3 speed of light, eg.</p>
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he quotes several physicists about clash of views.</p>
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but is consc time an illusion...</p>
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DB = Dean B... it is a mistake to dismiss brain's observations.</p>
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convex versus concave illusion... cuz light usually comes from above...
illusions are usually adaptive.</p>
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he argues local presentism...</p>
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he says... overstep to generalize from SR and Genl Rel to dismiss local presentism.</p>
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</p>