What if the speed of your brain impulses was reduced by half artificially? What would the perceived difference be? What if it was reduced to 10% of current speed? What about .001%? I think time would seem to be flowing faster for you since you are "checking in" less often, like in time dilation. Would you see movement in a strobelike fashion or would most movement be a blur? Objects would seem to be moving faster in any case. As the speed of thought approaches zero, the apparent speed of all objects would seem to approach the speed of light. What if you artificially INCREASED the speed of your brain to counteract the time dilation effect, maybe by increasing the conductance of the neurons as you accelerated?