Binding of the feature <i>stimulus duration</i> in the auditory domain: S-R or S-S binding; or both?

Perceiving and reacting to multidimensional objects creates so-called event files via feature binding. Bogon, Thomaschke, and Dreisbach provided the first evidence for the integration of the feature <i>stimulus duration</i> into such event files. However, their paradigm did not allow for differentiation between stimulus-stimulus and stimulus-response binding. This study used a classification task with many-to-one mappings to examine the integration of stimulus and response features independently. Experiment 1 used a pitch classification task. Participants had to respond with a left keypress to a low and a very low sine tone and with a right keypress to a high and very high sine tone. The four sine tones were presented for either a short or long duration, resulting in a total of eight stimuli. As an indicator of binding, we used partial repetition costs (better performance when both pitch/response and duration repeat or shift relative to partial repetitions). Results of Experiment 1 indicate stimulus-response binding and no stimulus-stimulus binding. In Experiment 2, instead of classifying the pitch of artificial sine tones, participants had to classify the type of musical instruments that produced the stimulus tones. Results replicated evidence for stimulus-response binding but also provided indications for stimulus-stimulus binding. Potential reasons for this result pattern and the relevance of duration in a musical context as one potential moderator of stimulus-stimulus bindings are discussed.