Abstract
Performance on time discrimination tasks is markedly worse when the stimulus defining intervals is a flashing light in comparison to auditory tones. Our work showed that time discrimination performance was significantly improved with a bouncing ball in relation to flashes, but only when speed information was robust. In contrast to discrimination, a time production task requires participants to reproduce a time interval. However, whether or not time interval production performance follows the same pattern as discrimination with these stimuli remained unknown. To investigate this, participants in the present study completed two timing tasks: a time interval discrimination task and a time interval production task. In the discrimination task, participants were asked to judge whether a test interval was shorter or longer compared to a standard interval. In the production task, participants reproduced each interval presented to them with two key presses, such that the time between their key presses mimicked the time interval. The visual stimuli were a white disk that flashed twice and a white disk that bounced twice to define a time interval. In the auditory condition, a time interval was defined by two beeps. Results of the discrimination task replicated our previous finding that time discrimination performance is improved with a bouncing ball stimulus over visual flashes, such that performance was comparable to performance with auditory beeps. In the production task with flash stimuli, participants showed a significant bias (overestimation at shortest interval, underestimation at longest interval) toward the center interval that was not observed in the other two stimuli. The pattern of more bias with the flash stimuli relative to the others is consistent with worse discrimination performance with flashes relative to bounces and beeps. In addition in the production task, performance was as good with visual bounces as with auditory beeps.