Time Interval Estimation: Internal Clock or Attentional Mechanism?

The human ability to accurately estimate time intervals in the order of 0 to 20 seconds can be explained by two seemingly incompatible theories: the internal clock and the attentional counter theory. Based on a dual timing task experiment we conclude that a symbiosis of both theories is necessary to explain all the phenomena found in our experiment and in the experiments we review. This conclusion is supported by the computational models we present of the experiments.