Time compression

This could be a long shot, but if you’re really enjoying yourself and you don’t want time to go too fast, try keeping your eyes as still as possible. Concetta Morrone, John Ross and David Burr have just reported in Nature Neuroscience that subjective time is compressed around the onset of a saccadic eye movement. Saccades are the rapid, jerky eye movements that we perform thousands of times every day (see Hack #17) to align targets of interest with the high-acuity fovea at the centre of our eyes.

Morrone’s team asked participants to compare the time interval between two horizontal bars that were flashed up around the onset of a saccade, with the interval between a second pair of horizontal bars flashed up after the saccade. Participants said the intervals felt the same when the gap between the first two bars was 100ms and the gap between the second pair was 50ms – that is, subjective time was speeded up by a factor of two near the saccade onset.

This finding complements earlier research showing that space is also compressed around the onset of a saccade. These perceptual distortions are probably caused by remapping processes in the brain’s lateral intraparietal area that are meant to compensate for the visual disruption caused by making so many jerky eye movements all the time (again, see Hack #17).

So how does this research tie in with the ‘stopped clock illusion’ (Hack #18), in which subjective time is extended for stimuli perceived after a saccade? The phenomena may be related, but the researchers pointed to some key differences: the stopped clock effect also occurs for auditory and tactile stimuli, and is dependent on the size of the saccade. In contrast, the time compression reported here only occurred with visual stimuli, not with auditory clicks, and was largely independent of saccadic size.