Is There an ‘Equalizing Tendency’ in Temporal Bisection in Humans?

Abstract Three experiments tested the conjecture that people carrying out a temporal bisection experiment have an ‘equalizing tendency’, that is, the idea that they are motivated to try to equalize the number of SHORT and LONG responses they produce. All three experiments varied instructions between two conditions. In one case, people were instructed to try to equalize, in the other it was emphasized that any proportion of SHORT and LONG responses was acceptable. Experiment 1 used short and long standards of 200 and 800 ms with comparisons spaced linearly, logarithmically, or reverse logarithmically between them, in three different groups. No effect of instructions was found in any group. Experiment 2 once again used 200 and 800 ms as the standards but had a range of comparisons closely spaced around the midpoint (500 ms), so most were ambiguous with respect to the standards. Again, no effect of instructions was found. Experiment 3 used smaller long/short ratios (300/200 ms or 800/533 ms). Once again, no effect of instructions was found. The three experiments together also replicated some previously obtained effects such as those of stimulus spacing and long/short ratio.