It is generally believed that time flows in one direction and that a reversal of time's arrow would render the external world non-sensical. We evaluated our ability to tell the direction of time's arrow in a wide range of dynamic scenes in our daily life by presenting 360 video clips in the correct or incorrect direction. Participants, who judged the direction in a speeded manner, erred in 39% of trials when a video was played in reverse, but in only 9% when it was played normally. Due to the bias favouring the ‘forward’ judgement, the reaction was generally faster for the forward response. However, the reaction became paradoxically faster and more synchronous for the detection of reversal in some critical occasions such as forward motion, free fall, diffusion, division and addition of materials by hand. Another experiment with a fraction of the video clips revealed that reversal replay of these videos provided instantaneous evidence strong enough to overtake the forward judgement bias. We suggest that our brain is equipped with a system that predicts how the external organisms behave or move in these critical occasions and that the prediction error of the system contributes to the fast ‘reversal’ detection.

No abstract

: This study investigated the effect of shape of words balloon on SNARC effect, which participants reacted to large numbers faster with the choice on the right, whereas the reverse relationship held true for small numbers. Dehaene et al. (1993) revealed that the SNARC effect occurs by customs of reading. This study hypothesized the SNARC effect will be obstructed in a lengthways balloon because Japanese participants read from top to down in a lengthways balloon. We used Arabic numerals from 1 to 9 except for 5. Numerals were displayed in the sideways or lengthways balloon. Participants judged numerals were even or odd by pushing the corresponding keys. From the results, ordinary SNARC effect occurred when the sideways balloon displayed but SNARC effect didn't occur when the lengthways balloon was displayed. This finding ensured that the SNARC effect is influenced due to directions of reading caused by shape of wards balloon.