Compression of time during smooth pursuit eye movements

Humans have a clear sense for the passage of time but while implicit motor timing is quite accurate explicit timing is prone to distortions particularly during action (Wenke & Haggard 2009) and saccadic eye movements (Morrone Ross & Burr 2005) Here we investigated whether perceived duration is also affected by the execution of smooth pursuit eye movements showing a compression of apparent duration similar to that observed during saccades To this end we presented two brief bars that marked intervals between 100 and 300 ms and asked subjects to judge their duration during fixation and pursuit We found a compression of perceived duration for bars modulated in luminance contrast of about 32% and for bars modulated in chromatic contrast of 14% during pursuit compared to fixation Interestingly Weber ratios were similar for fixation and pursuit if they are expressed as ratio between JND and perceived duration This compression was constant for pursuit speeds from 7 to 14 deg/s and did not occur for Intervals marked by auditory events These results argue for a modality-specific component in the processing of temporal information (C) 2010 Elsevier Ltd All rights reserve