Duration specificity in the long-range correlation of human serial interval production

Series of repeated intervals produced by humans can be characterised as fractional Gaussian noise (fGn). The scaling factor HH of fGn was determined for this task by means of the spectral maximum likelihood estimator across a continuous range of inter-response intervals (IRIs) covering 500–1624 ms. HH increased with IRI in a nonlinear fashion on both the individual and the group level. A discontinuity in this increase was indicated close to 1000 ms, consistent with results from other temporal tasks. Implications for conceptions of the human timing mechanism are discussed.