Simple and contingent aftereffects of perceived duration in vision and audition

After repeated presentations of a long inspection tone (800 or 1,000 msec), a test tone of intermediate duration (600 msec) appeared shorter than it would otherwise appear. A short inspection tone (200 or 400 msec) tended to increase the apparent length of the intermediate test tone. Thus, a negative aftereffect of perceived auditory duration occurred, and a similar aftereffect occurred in the visual modality. These aftereffects, each involving a single sensory dimension, aresimple aftereffects. The following procedures producedcontingent aftereffects of perceived duration. A pair of lights, the first short and the second long, was presented repeatedly during an inspection period. When a pair of test lights of intermediate duration was then presented, the first member of the pair appeared longer in relation to the second. A similar aftereffect occurred in the auditory modality. In these latter aftereffects, the perceived duration of a test light or tone is contingent—dependent—on its temporal order, first or second, within a pair of test stimuli. An experiment designed to test the possibility of cross-modal transfer of contingent aftereffects between audition and vision found no significant cross-modal aftereffects.     

Parameters affecting gap detection in the rat

The present research used a startle amplitude reduction paradigm to investigate the ability of the rat’s auditory system to track rapidly changing acoustic transients. Specifically examined was the ability of brief gaps in otherwise continuous noise to reduce the amplitude of a subsequently elicited acoustic startle reflex. The duration of the gap, time between gap offsetand startle elicitation (the interstimulus interval or ISI), and rise-fall characteristics of the gap were systematically varied. Consistent with previous research, gaps reliably reduced startle amplitude. Gaps 2 msec long were reliably detected, and a 50-msec ISI resulted in the greatest amplitude reduction. Gaps presented at short ISIs produced amplitude reduction that followed a different time course than did gaps presented at longer ISIs. These results may reflect differences in the length oftime available for the processing of the stimulus and may involve two different processes.     

Examining auditory kappa effects through manipulating intensity differences between sequential tones

The auditory kappa effect is a tendency to base the perceived duration of an inter-onset interval (IOI) separating two sequentially presented sounds on the degree of relative pitch distance separating them. Previous research has found that the degree of frequency discrepancy between tones extends the subjective duration of the IOI. In Experiment 1, auditory kappa effects for sound intensity were tested using a three-tone, AXB paradigm (where the intensity of tone X was shifted to be closer to either Tone A or B). Tones closer in intensity level were perceived as occurring closer in time, evidence of an auditory-intensity kappa effect. In Experiments 2 and 3, the auditory motion hypothesis was tested by preceding AXB patterns with null intensity and coherent intensity context sequences, respectively. The auditory motion hypothesis predicts that coherent sequences should enhance the perception of motion and increase the strength of kappa effects. In this study, the presence of context sequences reduced kappa effect strength regardless of the properties of the context tones.     

Shortening of subjective tone intervals followed by repetitive tone stimuli

Accumulated evidence shows that a subjective time interval is lengthened by preceding or concurrent presentation of flickers or repetitive tone stimuli that have been hypothesized to increase the frequency of pulse generation by a brain pacemaker. In the present study, we presented a series of repetitive tone stimuli after an interval that started and ended with tone markers. We found that subjective perception of the preceding interval was not lengthened but shortened by the tone stimuli that followed the interval. The perceived duration decreased as the frequency of the repetitive tone stimuli increased. The effect disappeared when the repetitive tone stimuli were delivered with a delay of 500 msec after the test interval or when continuous sound was delivered instead of delivering a rapid series of tones. On the basis of the results, we propose that the pulse count accumulated during a test interval was normalized by the clock frequency just after the test interval in a postdictive manner.     

Temporal course of perceived auditory duration

A series of experiments explored the temporal course of the perceived duration of an auditory stimulus. A backward recognition masking paradigm was utilized, in which the subject was to determine which of two target durations was presented on a given trial. The target tone was followed, after a variable silent intertone interval, by a masking tone which could assume one of three possible durations. Identification of the long target was found to improve consistently with increases in the intertone interval. In contrast, identification of the short target was as accurate at the short as at the long intertone intervals. Blocking the intertone interval across experimental sessions eliminated these differences between the two target tones. Performance on both the long and the short target tones improved monotonically with increases in the intertone interval. When masking tone duration was randomized within an experimental session, identification of the long (short) target was most accurate with the longer (shorter) masking tone. Blocking the duration of the masking tone across experimental sessions eliminated the effect of the duration of the mask, but did not alter any of the other results. A model, proposed to account for the results, assumes that the percept of target duration grows over time, and can be terminated by the onset of the masking tone. The masking tone also acts to lengthen the perceived duration of the target tone, and this lengthening is a direct function of the duration of the masking tone.     

Illusory continuity without sufficient sound energy to fill a temporal gap: Examples of crossing glide tones

The gap transfer illusion is an auditory illusion where a temporal gap inserted in a longer glide tone is perceived as if it were in a crossing shorter glide tone. Psychophysical and phenomenological experiments were conducted to examine the effects of sound-pressure-level (SPL) differences between crossing glides on the occurrence of the gap transfer illusion. We found that the subjective continuity-discontinuity of the crossing glides changed as a function of the relative level of the shorter glide to the level of the longer glide. When the relative level was approximately between -9 and +2 dB, listeners perceived the longer glide as continuous and the shorter glide as discontinuous, that is, the gap transfer illusion took place. The glides were perceived veridically below this range, that is, gap transfer did not take place, whereas above this range the longer glide and the shorter glide were both perceived as continuous. The fact that the longer glide could be perceived as continuous even when the crossing shorter glide was 9 dB weaker indicates that the longer glide's subjective continuity cannot be explained within the conventional framework of auditory organization, which assumes reallocation of sound energy from the shorter to the longer glide. The implicated mechanisms are discussed in terms of the temporal configuration of onsets and terminations and the time-frequency distribution of sound energy. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Illusory recouplings of onsets and terminations of glide tone components

We present a new auditory illusion, the gap transfer illusion, supported by phenomenological and psychophysical data. In a typical situation, an ascending frequency glide of 2,500 msec with a temporal gap of 100 msec in the middle and a continuously descending frequency glide of 500 msec cross each other at their central positions. These glides move at the same constant speed in logarithmic frequency in opposite directions. The temporal gap in the long glide is perceived as if it were in the short glide. The same kind of subjective transfer of a temporal gap can take place also when the stimulus pattern is reversed in time. This phenomenon suggests that onsets and terminations of glide components behave as if they were independent perceptual elements. We also find that when two long frequency glides are presented successively with a short temporal overlap, a long glide tone covering the whole duration of the pattern and a short tone around the temporal middle can be perceived. To account for these results, we propose an event construction model, in which perceptual onsets and terminations are coupled to construct auditory events and the proximity principle connects these elements.     

The effect of marker size on the perception of an empty interval

Research shows that the time that is spent perceiving a brief visual stimulus is experienced as increasing as the size of the stimulus increases. We examined whether the experienced duration of time that is spent attending the perception of an empty interval—demarcated by the offset of one marker and the onset of a second marker— depends on the size of the markers themselves. Previous theories predict that the perceived time that is spent viewing offset-to-onset intervals decreases as the size of the markers increases, and that the perceived time that is spent viewing the markers increases. We demonstrated that empty intervals between the presentations of large markers were perceived to be longer in duration than those occurring between the presentations of small markers, and that the second marker was critical to this effect of physical size on apparent duration. We report that the size effect disappeared when the interval was filled with the presentation of a circle, and we conclude that the intensity of the second marker altered perceptions in an empty-interval-specific manner.     

Accents in equitone sequences

Equitone sequences are defined as sequences of tones that are identical in all respects: frequency, spectral composition, intensity, and duration. The only parameter varied in these sequences is the time-interval between tones. In such sequences, clear accents are perceived. This paper describes accent perception in equitone sequences containing two alternating intervals; such sequences are perceived as consisting of repeating groups of two tones. An accent is heard on the first tone of a group if the difference between the intervals is about 5% to 10%. If the difference is made bigger, the accent is heard on the last tone of the group; this latter accent is considerably stronger than the accent previously heard on the first tone. In a number of experiments, the conditions under which the two types of accents occur were investigated. From these experiments, it was tentatively concluded that the accent on the last tone is heard because that tone, since it is followed by a longer interval, can be processed more completely. This “intervalproduced” accent indeed occurs only if the between-group interval is considerably longer than the within-group interval and if the latter does not exceed a duration of about 250 msec. The effect is slightly dependent on tone duration. The interval-produced accent can be balanced if the nonaccented tone is increased by about 4 dB in intensity. This shows that the effect is quite robust. The specific type of accentuation reported here might explain some rhythmical phenomena, examples of which are given.     

Effects of practice and signal energy on duration discrimination of brief auditory intervals

In Experiment 1, the proposition that duration discrimination of filled auditory intervals is based on temporal information rather than on energy-dependent cues was tested in 64 naive subjects. The subjects were presented with two auditory stimuli at different levels of intensity within one trial, and had to decide which of the two was longer in duration. An adaptive psychophysical procedure was used. As a measure of performance, difference threshold estimates in relation to a 50-msec standard interval were computed. Duration discrimination showed no effect of energy values, indicating that the subjects’ discrimination was independent of stimulus intensity. The goal of Experiments 2A and 2B was to investigate the effects of practice on duration discrimination which, in addition, may provide an indirect test for the potential use of energy-dependent cues. Effects of practice on duration discrimination of filled (Experiment 2 A) and empty (Experiment 2B) intervals were studied in 6 subjects in each case, over 20 testing sessions. An adaptive psychophysical procedure that was similar to the one used in Experiment 1 was applied. Neither short-term effects of practice based on the first five testing sessions, nor long-term effects of practice based on the means of 4 consecutive weeks, could be demonstrated. The results of the present study suggest that duration discrimination of brief auditory intervals is based on temporal information and not on stimulus energy. Furthermore, implications for the notion of a very basic bio-logical timing mechanism underlying temporal processing of brief auditory intervals in the range of milliseconds are discussed.     

Perceptual completion of a sound with a short silent gap

Listeners reported the perceptual completion of a sound in stimuli consisting of two crossing frequency glides of unequal duration that shared a short silent gap (40 ms or less) at their crossing point. Even though both glides shared the gap, it was consistently perceived only in the shorter glide, whereas the longer glide could be perceptually completed. Studies on perceptual completion in the auditory domain reported so far have shown that completion of a sound with a gap occurs only if the gap is filled with energy from another sound. In the stimuli used here, however, no such substitute energy was present in the gap, showing evidence for perceptual completion of a sound without local stimulation ('modal' completion). Perceptual completion of the long glide occurred under both monaural and dichotic presentation of the gap-sharing glides; it therefore involves central stages of auditory processing. The inclusion of the gap in the short glide, rather than in both the long and the short glide, is explained in terms of auditory event and stream formation.     

The effects of spatial frequency and target type on perceived duration

Two experiments are reported that attempt to demonstrate a critical role played by sensory persistence on a standard perceived-duration task employing brief visual stimuli. Experiment 1 examined the effect on perceived duration of varying the spatial frequency of a target. For both 40- and 70-msec flashes, increased spatial frequency resulted in reduced estimates of perceived duration. These results were contrasted with predictions derived from cognitive processing models of duration perception. In Experiment 2, three typical types of target employed in current research (an outlined circle, a “noise”-filled circle, and a completely filled circle) were shown to differ significantly in their perceived duration and in their sensitivity to increases in physical duration. The results were discussed in terms of variable degrees of retinal persistence produced by the three types of targets. The possible implications for specific discrepancies in the literature and across-study comparisons in general were enumerated.     

Shrinkage in the perceived duration of speech and tone by acoustic replacement1

Abstract: To investigate mechanisms for perceiving the duration of an auditory event, an effect of perceptual grouping upon perceived duration was studied psychophysically. In the first experiment, the perceived duration of a spoken word was measured under three conditions of acoustic continuity (i.e., (a) intact, (b) noise‐replaced, and (c) gap‐replaced) as a function of the duration of the target stimulus. Under the noise‐replaced condition, a portion of the target stimulus was physically replaced with a noise burst. Under the gap‐replaced condition, the replacement was made with a gap. The gap‐replacement resulted in a prominent shrinkage of the perceived duration. In the case of noise‐replacement, the amount of shrinkage was moderate but highly significant, although the word employed was perceived to be phonetically intact. Independent of this effect of replacement, the amount of shrinkage was also affected by the physical duration of the target stimulus. The second experiment tested an effect of noise replacement on the perceived duration of a tone burst. In this case, the noise replacement also shrunk the perceived duration of the non‐speech stimulus. This noise‐induced shrinkage could be regarded as being general for the auditory duration. The phenomenon is discussed in relation to a revised model for perceived duration.     

Why 'Sounds Are Judged Longer Than Lights': Application of a Model of the Internal Clock in Humans

Three experiments, using temporal generalization and verbal estimation methods, studied judgements of duration of auditory (500-Hz tone) and visual (14-cm blue square) stimuli. With both methods, auditory stimuli were judged longer, and less variable, than visual ones. The verbal estimation experiments used stimuli from 77 to 1183 msec in length, and the slope of the function relating mean estimate to real length differed between modalities (but the intercept did not), consistent with the idea that a pacemaker generating duration representations ran faster for auditory than for visual stimuli. The different variability of auditory and visual stimuli was attributed to differential variability in the operation of a switch of a pacemaker-accumulator clock, and experimental datasuggested that such switch effects were separable from changes in pacemaker speed. Overall, the work showed how a clock model consistent with scalar timing theory, the leading account of animal timing, can address an issue derived from the classical literature on human time perception.     

Change perception in complex auditory scenes

In four experiments, we examined the role of auditory transients and auditory short-term memory in perceiving changes in a complex auditory scene comprising multiple auditory objects. Participants were presented pairs of complex auditory scenes that were composed of a maximum of four animal calls delivered in free field; participants were instructed to decide whether the two scenes were the same or different (Experiments 1, 2, and 4). Changes to the second scene consisted of either the addition or the deletion of one animal call. Contrary to intuitive predictions based on results from the visual change blindness literature, substantial deafness to the change emerged without regard to whether the scenes were separated by 500 msec of masking white noise or by 500 msec of silence (Experiment 1). In fact, change deafness was not even modulated by having the two scenes presented contiguously (i.e., 0-msec interval) or separated by 500 msec of silence (Experiments 2 and 4). This result suggests that change-related auditory transients played little or no role in change detection in complex auditory scenes. Instead, the main determinant of auditory change perception (and auditory change deafness) appears to have been the capacity of auditory short-term memory (Experiments 3 and 4). Taken together, these findings indicate that the intuitive parallels between visual and auditory change perception should be reconsidered.     

The role of tone duration in dichotic temporal order judgment

Over the past two decades, a number of studies have been based on the dichotic temporal order judgment (TOJ) paradigm, to compare auditory temporal processing in various subpopulations to that of young, normal controls. The reported estimates of dichotic TOJ thresholds, expressed as the interstimulus intervals (ISIs) for 75 % accuracy among the controls, have varied. In the present study, we examined the influence of tone duration, within the 10- to 40-msec range, on dichotic TOJ accuracy and threshold. The results indicated that increases in either ISI or tone duration increased dichotic TOJ accuracy similarly, implying that changes in tone duration may affect dichotic TOJs simply by adding to the delay between onset of the tone at the lead ear and onset of the tone at the lag ear. The dichotic TOJ thresholds from three published studies that had used tones as stimuli and the dichotic thresholds from the present study all fell within 0.5 standard deviations from the theoretical line of a 10-msec reduction in threshold for every 10-msec increase in tone duration. When the dichotic TOJ threshold data from the present study and from the published studies were converted to stimulus onset asynchronies (SOAs) and plotted as a function of tone duration, they fell very close to or on a zero-slope line, indicating that when ISI and duration are summed to yield an SOA, dichotic TOJ thresholds are invariant to tone duration within the range of 10–40 msec.     

Visual dominance in the pigeon

In Experiment 1, three pigeons were trained to obtain grain by depressing one foot treadle in the presence of a 746-Hertz tone stimulus and by depressing a second foot treadle in the presence of a red light stimulus. Intertrial stimuli included white light and the absence of tone. The latencies to respond on auditory element trials were as fast, or faster, than on visual element trials, but pigeons always responded on the visual treadle when presented with a compound stimulus composed of the auditory and visual elements. In Experiment 2, pigeons were trained on the auditory-visual discrimination task using as trial stimuli increases in the intensity of auditory or visual intertrial stimuli. Again, pigeons showed visual dominance on subsequent compound stimulus test trials. In Experiment 3, on compound test trials, the onset of the visual stimulus was delayed relative to the onset of the auditory stimulus. Visual treadle responses generally occurred with delay intervals of less than 500 milliseconds, and auditory treadle responses generally occurred with delay intervals of greater than 500 milliseconds. The results are discussed in terms of Posner, Nissen, and Klein's (1976) theory of visual dominance in humans.     

A new temporal illusion or the TOE once again?

Recently, Nakajima, ten Hoopen, and van der Wilk (1991) and Nakajima, ten Hoopen, Hilkhuysen, and Sasaki (1992) described what they believed to be a new illusion of auditory time perception. They reported that the perceived duration of a temporal interval was influenced by an immediately preceding or succeeding temporal interval The influence of a neighboring temporal interval on perceived duration is not a new illusion, however, but is another demonstration of the time-order error     

The structure of sensory events and the accuracy of time judgments

We investigated how does the structure of empty time intervals influence temporal processing. In experiment 1, the intervals to be discriminated were the silent durations marked by two sensory signals, both lasting 10 or 500 ms; these signals were two identical flashes (intramodal: VV), or one visual flash (V) followed by an auditory tone (A) (intermodal: VA). For the range of duration under investigation (standards = 0.2, 0.6, 1, or 1.4 s), the results indicated that both the marker length and sensory mode influenced discrimination, but no interaction between these variables or between one of these variables and standard duration was significant. In experiment 2, we compared, for each of four marker-type conditions (VV, AA, VA, AV; and standard = 1 s), intervals marked by two 10 ms signals with intervals marked by unequal signal length (markers 1 and 2 lasting 10 and 500 ms, or 500 and 10 ms). As in experiment 1, the results revealed significant marker-mode and marker-length effects, but no significant interaction between these variables. Experiment 3 showed that, for the same conditions as in experiment 2, perceived duration is not influenced by marker length and that the variability of interval reproductions does not depend on the perceived duration of intervals. The results are discussed in the light of a single-clock hypothesis: marker-length and marker-mode effects are presented as being non-temporal sources of variability associated mainly with sensory and memory processes.     

Audition dominates vision in duration perception irrespective of salience,attention, and temporal discriminability

Whereas the visual modality tends to dominate over the auditory modality in bimodal spatial perception, the auditory modality tends to dominate over the visual modality in bimodal temporal perception. Recent results suggest that the visual modality dominates bimodal spatial perception because spatial discriminability is typically greater for the visual than for the auditory modality; accordingly, visual dominance is eliminated or reversed when visual-spatial discriminability is reduced by degrading visual stimuli to be equivalent or inferior to auditory spatial discriminability. Thus, for spatial perception, the modality that provides greater discriminability dominates. Here, we ask whether auditory dominance in duration perception is similarly explained by factors that influence the relative quality of auditory and visual signals. In contrast to the spatial results, the auditory modality dominated over the visual modality in bimodal duration perception even when the auditory signal was clearly weaker, when the auditory signal was ignored (i.e., the visual signal was selectively attended), and when the temporal discriminability was equivalent for the auditory and visual signals. Thus, unlike spatial perception, where the modality carrying more discriminable signals dominates, duration perception seems to be mandatorily linked to auditory processing under most circumstances.