Effects of stimulus order on discrimination sensitivity for short and long durations

Abstract

Previous studies have shown that discrimination sensitivity in 2AFC tasks depends on the presentation order of the standard and comparison stimulus. The present study examined whether this so-called Type B effect generalizes across different standard magnitudes. Therefore, Experiment 1 employed an auditory duration discrimination task with short (100 ms) and long (1,000 ms) standard durations and a constant interstimulus interval (ISI) of 1,000 ms. For both standard durations, a clear Type B effect emerged. In Experiment 2, discrimination sensitivity was assessed for short (300 ms) and long (1,000 ms) ISIs and a constant standard duration of 100 ms, in order to examine whether the Type B effect diminishes or even reverses when both stimuli are presented in rapid succession, as was suggested by previous studies. In the short, but not the long ISI condition, the Type B effect was virtually eliminated. Taken together, the present experiments suggest that the Type B effect is robust across standard magnitude, but diminishes when the time interval between both stimuli is reduced. This result pattern is discussed within the framework of the Internal Reference Model and the Sensation Weighting Model. It is also demonstrated that both models provide a quantitative account of the present results. In typical psychophysical tasks such as the two-alternative forced-choice (2AFC) task, participants are asked to discriminate between a fixed-magnitude standard stimulus s and a variable comparison stimulus c, whose magnitude can be lower, equal to or higher than the magnitude of the standard. In the temporal 2AFC task, these two stimuli are presented successively in one of two temporal orders, that is, sc and cs , to balance for potential effects of stimulus order on task performance. Researchers often disregard such order effects by aggregating data across stimulus order. However, if the observed data are analyzed separately for the two stimulus orders, order effects are commonly observed. For example, the order-conditional psychophysical functions observed in a typical 2AFC task might be shifted horizontally from the point of objective equality (i.e., a Type A order effect or time-order error), such that the magnitude of the first stimulus is either judged to be higher or lower than the magnitude of the second one. Theoretically, this might be the sign of a perceptual, decisional, or response bias, and has been extensively studied (cf. Eisler, Eisler, & Hellström, 2008). More important for the purpose of the present study, however, is the so-called Type B order effect (Ulrich 2010;Ulrich & Vorberg, 2009). This effect refers to the phenomenon that the spread of the order-conditional psychometric functions may differ with regard to stimulus order. Specifically, the difference limen (DL) is typically larger and thus discrimination sensitivity

Time-order errors and standard-position effects in duration discrimination: An experimental study and an analysis by the sensation-weighting model

“…One exception is Hellström and Rammsayer (2004), who, using a 50-ms standard and interstimulus intervals of 100 through 2,700 ms, obtained consistently positive SPEs. Another exception is the recent study by Bausenhart, Dyjas, and Ulrich (2015), using an adaptive method, in which negative SPEs were found for filled auditory intervals with 100-ms and 1,000-ms standards and an interstimulus interval of 1,000 ms. With a 100ms standard, the SPE vanished when the interstimulus interval was shortened to 300 ms, but it did not reverse into positive except for a few participants.…”

“…With this kind of model, the authors account for the Bcontraction bias^in their experimentthat is, TOEs that are positive for low, and negative for high, magnitudes. (In their experiment, unlike those of Bausenhart et al 2015, both stimuli were varied, which made the TOEs visible.) This explanation may be plausible in most experimental conditions, but not in those of Hellström (1979Hellström ( , 2003 with brief, but by no means extreme, stimulus durations and interstimulus intervals.…”

Prospective and Retrospective Timing Processes: Theories, Methods, and Findings

“…Moreover, using a roving or a reminder method also has an impact on duration discrimination: Discrimination is better with the reminder method-that is, with the standard interval kept constant in the first position (Grondin & McAuley 2009;Hellström & Rammsayer 2004). The time-order effect is sometimes referred to as a Type-A effect, and the fact of having better performances in the standard-comparison order than in the comparison-standard order is sometimes referred to as a Type-B effect (Bausenhart, Dyjas, & Ulrich, 2015), or standard position effect (Hellström & Rammsayer 2015). Time-order errors tend to be negative for relatively short durations-that is, the second duration is judged as longer than the first-but tend to be positive for relatively longer durations, especially those judged in retrospect-that is, the first duration is judged longer than the second (Block 1985).…”

Eliciting contextual temporal calibration: The effect of bottom-up and top-down information in reproduction tasks

“…Another example of how prior knowledge can affect behavioral performance from the time perception literature is the work of Dyjas, Bausenhart, and Ulrich (2014) on stimulus order effects in interval comparison tasks. Typically, discrimination performance is lower if the comparison interval precedes the standard interval (Bausenhart, Dyjas, & Ulrich, 2015;Lapid, Ulrich, & Rammsayer, 2008). However, when participants are informed about the stimulus order before a trial starts, this effect is greatly reduced suggesting that participants have, to a certain degree, top-down control on the processing of intervals .…”