The greater temporal acuity in the reminder task than in the 2AFC task is independent of standard duration and sensory modality.

Abstract

The present study compared estimates of the difference limen (DL) from the reminder and the two-alternative forced-choice task (2AFC) task. Both tasks used exactly the same set of stimulus values and also the same adaptive method for estimating DL. The magnitude of the standard stimulus was varied over a large range. In two experiments, participants discriminated the duration of two successively presented auditory and visual stimuli, respectively. The results are unambiguous. DL estimates from the 2AFC task were considerably larger than the ones from the reminder task. This difference between the two performance estimates was rather stable across the range of standards used and across both sensory modalities. These results reinforce the conclusion by Lapid, Ulrich, and Rammsayer (2008) that the 2AFC task produces consistently higher values of DL than the reminder task. Furthermore and most important, the present data indicate that the observed shape of the Weber function is not influenced by the psychophysical method applied.