Two possible trials in experiment 1: one trial in the Freq-No noise condition (a) and one trial in the Freq-Noise condition (b). Each horizontal segment represents a pure tone and the filled rectangular areas represent noise bursts. The pure tones form four successive chords. The first and third chords are the “precursor” chord and the second and fourth chords are the “test” chord. Note that in each panel the only difference between the precursor and test chords is that the second component tone of the test chord is slightly higher in frequency than the second component tone of the precursor chord. This changing tone is the target tone for the trials depicted here. In each panel, the rightmost horizontal segment represents the probe tone. The correct response is “present” for (a) and “absent” for (b). In the experiment, the duration of the tones and noise bursts varied across subjects, but this duration was always much smaller than the 500-ms time interval separating the successive chords or noise bursts.
Mean d′ values obtained in the six conditions of experiment 1. Each data point represents the outcome of 2000 trials (400 trials for five subjects).
Results obtained in the three conditions of experiment 2. Thin lines connect the individual values of d′ (400 trials per condition and subject). Thick lines connect the means of these values.
Results obtained in the five conditions of experiment 3. Thin lines connect the individual values of d′ (400 trials per condition and subject). Thick lines connect the means of these values.
Article metrics loading...
Full text loading...