Tau and Kappa Effects: The Case of Space-Like-Extent Frequencies

The organization of tonal-temporal information in a memory task was studied in two experiments. The stimuli consisted of four different configurations of eight beeps, presented sequentially. In two configurations, the stimuli were tonal-time congruent, with (constant or variable) inter-stimulus tonal distances corresponding to (constant or variable) inter-stimulus time intervals. In the two other configurations, the stimuli were tonal-time incongruent, with (constant or variable) inter-stimulus tonal distances not corresponding to (variable or constant) inter-stimulus time intervals. After a learning phase consisting of 20 presentations of the target configuration, participants reproduced the spatial (Experiment 1) or temporal (Experiment 2) characteristics of the target 60 times in succession without ever re-examining the target configuration. Classically, in incongruent space-time conditions, the effects of variable inter-stimulus time intervals or inter-stimulus space intervals on the reproduction of constant distances (Tau effect) and constant durations (Kappa effect), respectively, are observed. However, our results showed that this was not the case when the spatial dimension was substituted for the tonal dimension (i.e., the distances between consecutive tones). The results are discussed in the light of the properties of the physical versus frequential space, that is, of a tonal dimension in which the different frequencies were considered as the spatial dimension.