The tau effect, an effect of temporal intervals on the perception of spatial separation or sensory difference, has been observed in various sense modalities, including pitch bisection judgments in audition. However, systematic studies on the mechanism of the auditory tau effect have been rather scarce. In the present study, experiments were carried out using the AXB method to investigate the auditory tau effect on the pitch perception of pure tones (Experiment 1), the auditory tau effect on perception of the lei-Iii, , and the kappa effect-an effect of sensory differences on the perception of temporal intervals-on the perception of pure tones and synthetic vowels (Experiment 3). The results demonstrated that the auditory tau effect occurs not only in the pitch perception of pure tones, but also in the phonetic perception of the III-Iii and Iii-III continua of synthetic vowels. The reverse pattern of results was obtained in the lei-Iii and Iii-lei continua. The kappa effect was found both in the pitch perception of pure tones and in phonetic judgments of synthetic vowels. These findings suggest that the interaction between temporal interval and pitch (or phonetic) perception can be explained on the basis of the integration of forward and backward context effects, and that the auditory tau and kappa effects occur at an early stage of auditory information processing.Many experiments have been conducted on the timespace relationship in perception. For example, the tau effect is usually cited as evidence for the dependence of space perception on time. The tau effect was first identified by Helson (1930) in tactile perception. He found that when two points are stimulated successively, the perceived distance between the points varies as a function of the temporal interval separating the two points. More specifically, if three points are marked off on an observer's skin and the temporal interval between the stimulation of the first and second points is greater than that between the second and third, the observer reports that the spatial distance between the first and second points is greater than that between the second and third, even though, in fact, it may be physically equal or less. A few years later, Geldreigh (1934) demonstrated an analogous effect in visual perception, and Billand Teft (1969) confirmedthis visualtau effect.Meanwhile, Cohen, Hansel, and Sylvester (1954), using the method of adjustment, found an effect similar to the tau effect in bisection judgments for pitch and labeled it the "auditory tau effect." If a subject hears, through headphones, a repeated succession of three different tones 9 of brief and equal duration and is asked to adjust the middle tone to appear to be intermediate in pitch between the other two tones, when the tone is temporally close to either of the two comparison tones it is judged as more different in frequency than when it is more temporally distant. Cohen, Christensen, and Ono (1974) found that this auditory tau effect occurs monaurally as well as binaurally, and they prop...

The auditory tau and the kappa effects show that there is time-pitch interdependence in our perception. Our judgments of pitch separation between two tones depend on the temporal interval between them (the auditory tau effect), and our judgments of the tones' temporal interval depend on their pitch separation (the kappa effect). The mechanisms underlying this interdependence were investigated by studying the auditory tau and the kappa effect in three experiments. Comparisons were made between results obtained from subjects with absolute pitch and those who did not have absolute pitch, and two frequency ranges of pure tones (octave and whole-tone conditions) were selected. The procedures had been used in previous experiments (Shigeno, 1986), in which the auditory tau and the kappa effects were compared in speech and nonspeech stimuli. The present results demonstrate that the auditory tau effect does not occur when possessors of absolute pitch judge the closeness of stimuli in pitch, except when the stimulus continuum consists of tones that do not correspond to musical notes in the whole-tone condition. The kappa effect was obtained in the judgment of possessors of absolute pitch in both the octave and the wholetone conditions. These findings suggest that the interaction between temporal interval and pitch judgment might be explained in terms of the two different memory modes for retaining the pitch of tones, and that these effects occur at the precategorical level.The relationship between temporal and spatial perception has been of interest in psychology. The tau and kappa effects are usually cited as evidence for the dependence of spatial perception on temporal separation and for the dependence of temporal perception on spatial distance, respectively. The tau effect was first identified by Helson (1930) in tactile perception. He found that when two points are stimulated successively, the perceived spatial distance between them varies as a function of the temporal interval between the stimulations. Thus, if three points are marked off on an observer's skin and the temporal interval between the stimulation of the first and second points is greater than that between the second and third, the observer reports that the spatial distance between the first and second points is greater than that between the second and third, even though, in fact, it may be physically equal or less. Cohen, Hansel, and Sylvester (1954), using the method of adjustment, found an effect similar to the tau effect in bisection judgments of pitch and labeled it the auditory tau effect. In the auditory tau experiment, a subject hears a succession of three different tones of brief and equal duration-but with unequal temporal spacing-and is asked to adjust the middle tone to appear to be intermediate in pitch between the other two. When the middle tone is temporally close to either of the two neighboring tones, This research was supported in part by Grant-in-Aid for Scientific Research 02610064 from the Ministry of Education, Science, and Culture. ...

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Two experiments were conducted to investigate whether or not anchoring and selective adaptation induce basically the same psychological effects. The purpose of the first experiment is to show how an audiovisual anchor modifies the perception of consonant-vowel (CV) syllables. The anchors were two purely acoustical, two purely optical, and three audiovisual CV syllables. The results were compared with those of audiovisual speech selective-adaptation experiments conducted by Roberts and Summerfield [Percept. Psychophys. 30, 309-314 (1981)] and Saldaña and Rosenblum [J. Acoust. Soc. Am. 95, 3658-3661 (1994)]. The audiovisual anchoring effects were found to be very similar to the audiovisual selective-adaptation effects, but the incompatible audiovisual anchor produced more auditory-based contrast than the purely acoustical anchor or the compatible audiovisual anchor. This difference in contrast had not been found in the previous selective-adaptation experiments. The second experiment was conducted to directly compare audiovisual anchoring and selective-adaptation effects under the same stimuli and with the same subjects. It was found that the compatible audiovisual syllable (AbVb) caused more contrast in selective adaptation than in anchoring, although the discrepant audiovisual syllable (AbVg) caused no difference between anchoring and selective adaptation. It was also found that the anchor AbVg caused more auditory-based contrast than the anchor AbVb. It is suggested that the mechanisms behind these results are different.