The relative magnitude (or intensity) of an event can have direct implications on timing estimation. Previous studies have found that greater magnitude stimuli are often reported as longer in duration than lesser magnitudes, including Arabic digits (Xuan, Zhang, He, & Chen, 2007). One explanation for these findings is that different quantitative dimensions (size, intensity, number) are processed and represented according to a common analog magnitude system (Walsh, 2003). In the current study, we examined whether there were commonalities in how people judge the intervals of time occurring between discrete stimuli of different magnitudes across a variety of quantitative dimensions, which included number, size, and color saturation. It was found that duration judgments increased systematically as the overall magnitude difference between sequentially presented stimuli increased. This finding was robust against manipulations to the direction of the sequence, or whether the sequence followed ordered (continuous) or nonordered (discontinuous) pattern trajectories.

The cross-modal impact of number magnitude (i.e. Arabic digits) on perceived sound loudness was examined. Participants compared a target sound's intensity level against a previously heard reference sound (which they judged as quieter or louder). Paired with each target sound was a task irrelevant Arabic digit that varied in magnitude, being either small (1, 2, 3) or large (7, 8, 9). The degree to which the sound and the digit were synchronized was manipulated, with the digit and sound occurring simultaneously in Experiment 1, and the digit preceding the sound in Experiment 2. Firstly, when target sounds and digits occurred simultaneously, sounds paired with large digits were categorized as loud more frequently than sounds paired with small digits. Secondly, when the events were separated, number magnitude ceased to bias sound intensity judgments. In Experiment 3, the events were still separated, however the participants held the number in short-term memory. In this instance the bias returned.

No abstract

The auditory kappa effect is a tendency to base the perceived duration of an inter-onset interval (IOI) separating two sequentially presented sounds on the degree of relative pitch distance separating them. Previous research has found that the degree of frequency discrepancy between tones extends the subjective duration of the IOI. In Experiment 1, auditory kappa effects for sound intensity were tested using a three-tone, AXB paradigm (where the intensity of tone X was shifted to be closer to either Tone A or B). Tones closer in intensity level were perceived as occurring closer in time, evidence of an auditory-intensity kappa effect. In Experiments 2 and 3, the auditory motion hypothesis was tested by preceding AXB patterns with null intensity and coherent intensity context sequences, respectively. The auditory motion hypothesis predicts that coherent sequences should enhance the perception of motion and increase the strength of kappa effects. In this study, the presence of context sequences reduced kappa effect strength regardless of the properties of the context tones.

In the current study, we examined how the contextual repetition of magnitude information presented in either symbolic (Arabic digits) or nonsymbolic (numerosities) formats impacted on the perceived duration of a later occurring target number. The results of the current study demonstrated a time-magnitude bias in which, on average, large magnitude target numbers were judged to last for longer durations relative to small magnitude target numbers, regardless of notation (symbolic number and numerosity). Furthermore, context effects were found, in which a greater discrepancy in the target's magnitude from the initial context led to longer perceived duration ratings. However, this was found to be asymmetrical, occurring only for large magnitude targets. Additionally, the type of context effect was shown to be determined by whether the context was presented in the same notation as the target or a different notation.