Figure 1.

Relative-timing conditions. Schematic diagrams of the signal and standard observation periods in each two-interval forced-choice trial for four relative-timing conditions: asynchrony onset (A), order onset (B), asynchrony offset (C), and order offset (D). All stimuli consisted of two-tone complexes in which the duration of the higher frequency tone was always 500 ms. The frequencies of the tones depended on the condition parameters (see Fig. 3 and Materials and Methods). Freq, Frequency.