Detecting changes in simulated events using partial‐interval recording and momentary time sampling

In a series of three studies, we evaluated simulated data with reversal designs to determine whether partial‐interval recording (PIR) and momentary time sampling (MTS) detected changes that were evident with continuous measures. The results from Study 1 showed that MTS with interval sizes up to 30 s detected most of the moderate and large changes in duration events and MTS with interval sizes up to 1 min detected most large changes in duration events. By comparison, PIR with 10‐s intervals detected approximately half of all changes in duration events. The results of Study 2 showed that only 10‐s PIR reliably detected most small, moderate, and large changes in frequency events. The results of Study 3 showed that PIR with 10‐s intervals generated a relatively high percentage of false positives for duration events, whereas MTS did not. As a whole, the results support previous findings, but also provide new guidelines for the use of PIR and MTS. Copyright © 2008 John Wiley & Sons, Ltd.     

ERP predictors of individual performance on a prospective temporal reproduction task

The present study aimed at investigating whether different aspects of performance on a prospective reproduction task with a standard duration of 2 s had different antecedents in the event-related potentials (ERPs) accompanying standard presentations and reproduced intervals. On each trial, first the standard duration was presented as an empty auditory interval. After a short delay, participants reproduced this interval by means of two button presses defining onset and offset of the reproduced interval. About 25 participants were divided into groups of poor and good time estimators, once based on the coefficient of variation of their reproduced durations, and once based on the absolute error score. Interestingly, for both performance measures differences between participants were accompanied by ERP differences during standard presentations rather than reproduction itself. While larger P300 amplitudes evoked by standard interval offset predicted good reproduction performance in terms of a small coefficient of variation, small absolute error scores were accompanied by larger fronto-central negative slow wave during standard presentations. The results suggest an important role of attention to both the critical events that delimit the to-be-estimated temporal intervals, and to the passing of time between these events.     

Contextual relative temporal duration judgment: an investigation of sequence interruptions

How do listeners judge relative duration? There currently are three primary classes of proposed timing mechanisms: interval based (judgments of discrete events), beat based (judgments of beat synchrony), and oscillator based (judgments of relative phase or synchrony). In the present research, these mechanisms were examined in terms of predictions both about how an induction sequence of preceding intervals affects relative temporal duration comparison in a simple, two-interval task and about how a pause (e.g., an interstimulus interval) within the presented sequence affects relative temporal duration judgment. Results indicated that a relative temporal judgment was best when all intervals preceding the to-be-judged interval were equal in duration to the to-be-judged interval. Results also indicated that whereas short pauses significantly impair a relative temporal duration judgment, long pauses generally do not reduce the effectiveness of the induction sequence. The results are not entirely consistent with current conceptualizations of any of the proposed mechanisms but can be fully accommodated with simple modifications to the oscillator-based mechanism.     

Age-related changes in auditory temporal processing

Two tone bursts separated by a silent interval and imbedded in a background white noise were presented to elderly subjects (M age = 71.3 years) and young subjects (M age = 22.2 years). Subjects were required to judge when the two tone bursts fused perceptually by adjusting the duration of tone-one. The bursts were separated by six discrete interstimulus intervals of 4, 8, 16, 24, 32, or 40 ms. The tone-two burst was held constant at 100 ms. Fusion point was defined as that critical tone-one duration at which the two tones fused (were perceived as one). Elderly subjects reached fusion point at longer critical tone-one durations than young subjects at each interval tested. The function relating tone-one duration and interval conformed to an exponential curve and is discussed with respect to an exponential decay model of the inhibitory interactions of neural systems responding to onsets and offsets of sensory events.     

Temporal control of periodic schedules: signal properties of reinforcement and blackout

Pigeons were exposed to periodic food-reinforcement schedules in which intervals ended with equal probability in either reinforcement or brief blackout. The effects on the pattern of key pecking of sequential probability of reinforcement, interval duration, and time to reinforcement opportunity were investigated in three experiments. The major results were: (1) at short absolute interval durations, time to reinforcement opportunity determined both postreinforcement and postblackout pause (time to first key peck within an interval); (2) at long intervals, postblackout pause was consistently shorter than postreinforcement pause, even if both events signalled the same time to the next reinforcement opportunity (omission effect); (3) when reinforcement and blackout signalled different times to the next reinforcement opportunity, within the same experiment, there was some evidence for interactions analogous to behavioral contrast.     

Internal representation of simple temporal patterns

In this study the imitation of several periodically repeating simple temporal patterns consisting of two or more intervals varying in their duration ratios has been investigated. The errors that subjects typically made in their imitations and the systematic changes that occurred during repeated imitations indicate that both musically trained and untrained subjects map temporal sequences onto an interval structure the nature of which is revealed by studying which patterns are correctly and which incorrectly reproduced. A "beat-based" model for the perception of temporal sequences is proposed. This model states that the first step in the processing of a temporal sequence consists of a segmentation of the sequence into equal intervals bordered by events. This interval is called the beat interval. How listeners select this beat interval is only partly understood. In a second step, intervals smaller than the beat interval are expressed as a subdivision of the beat interval in which they occur. The number of within-beat structures that can be represented in the model is, however, limited. Specifically, only beat intervals that are subdivided into either equal intervals or intervals in a 1:2 ratio fit within the model. The partially hierarchical model proposed, though in need of further elaborations, shows why the number of temporal patterns that can be correctly conceptualized is limited. The relation of the model to other models is discussed.     

Mechanisms of perceptual timing: Beat-based or interval-based judgements?

Summary What is the nature of the human timing mechanism for perceptual judgements about short temporal intervals? One possibility is that initial periodic events, such as tones, establish internal beats which continue after the external events and serve as reference points for the perception of subsequent events. A second possibility is that the timer records the intervals produced by events. Later, the stored intervals can be reproduced or compared to other intervals. A study by Schulze (1978) provided evidence favoring beat-based timing. In contrast, our two experiments support an interval theory. The judgements of intervals between tones is not improved when the events are synchronized with internal beats established by the initial intervals. The conflict between the two sets of results may be resolved by the fact that an interval timer can recycle from one interval to the next, thus operating in a beat-like mode. However, a timer of this sort is just as accurate when comparing intervals that are off the beat.     

Reversing the course of forgetting

Forgetting functions were generated for pigeons in a delayed matching-to-sample task, in which accuracy decreased with increasing retention-interval duration. In baseline training with dark retention intervals, accuracy was high overall. Illumination of the experimental chamber by a houselight during the retention interval impaired performance accuracy by increasing the rate of forgetting. In novel conditions, the houselight was lit at the beginning of a retention interval and then turned off partway through the retention interval. Accuracy was low at the beginning of the retention interval and then increased later in the interval. Thus the course of forgetting was reversed. Such a dissociation of forgetting from the passage of time is consistent with an interference account in which attention or stimulus control switches between the remembering task and extraneous events.     

Time-shrinking,its propagation,and Gestalt principles

When a relatively short empty time interval is preceded by an even shorter one, its duration can be underestimated remarkably. This phenomenon, called time-shrinking, has been investigated with patterns consisting of two time intervals. In five experiments, we investigated whether underestimation of the last interval would occur when it was preceded by two time intervals. Significant underestimations of the last interval occurred in some of those patterns. The influence of the second preceding interval was dominant, but in some patterns, the first preceding interval could shrink the subjective duration of the last time interval directly. The first interval could also affect perception of the duration of the last one indirectly by shrinking the second interval, as a result of which the latter either shrank the last interval more strongly or became too short to shrink it. There were two types of temporal patterns in which the perceived duration of the last interval could not be explained by time-shrinking or its propagation through the pattern. It seemed plausible that auditory Gestalt principles invoked strong figural organizations in these patterns, which rendered the time-shrinking mechanism inoperative.     

Rapid acquisition of discrete-trial lever-press avoidance: effects of signal-shock interval

Acquisition of discrete-trial lever-press avoidance learning was studied in three experiments. Experiment I compared a new training procedure, which produces rates of lever-press avoidance learning comparable to those obtained in shuttle boxes, with a “conventional”, less efficient training procedure. A factorial design was used to compare continuous versus intermittent shock and a long-variable versus a short-fixed signal-shock interval. Learning was best in the groups trained with the long and variable interval and poorest in those trained with the short and fixed interval. Type of shock had no effect. Experiment II separated the effects of duration from those of variability of the signal-shock interval. Fixed and variable intervals of 10 and 60 sec were tested and duration was the only significant factor. Experiment III addressed the effect of the differential opportunity to avoid provided by long signal-shock intervals by varying this interval from 10 to 60 sec in 10-sec steps. Only the 10-sec group showed slow acquisition relative to the others. Analysis of avoidance response latencies showed that the distributions for all groups were positively skewed and that skewness increased with increasing duration of the signal-shock interval. At intervals longer than 20 sec, the animals made progressively less use of their increased opportunity to respond. The data do not support the opportunity-to-respond interpretation of the effects of duration of signal-shock interval and suggest that some type of inhibitory process may block lever-press avoidance learning at intervals as short as 10 sec. The significance of these findings for species-specific defense reaction and preparedness theories was emphasized.     

不同时距加工机制的比较:来自ERP的证据(Ⅰ)

采用事件相关电位的方法分析了不同时距加工机制的差异。实验采用时间两分任务,要求被试形成短(400ms)和长(1600ms)的时间判断标准,然后对7个刺激系列进行短、长的判断。结果表明时间知觉过程可以诱发出一种类似于CNV的慢性负波。对于400ms的短时距加工存在显著的半球效应,右半球的波幅显著高于左半球。1600ms的时距加工没有表现出明显的半球效应。不同时距的加工存在显著的差异。1600ms比400ms加工诱发出更大的CNV波幅。     

Impaired short temporal interval discrimination in a dyslexic adult

The ability to discriminate short temporal intervals was examined in a dyslexic adult (E.C.) and six matched controls. Listeners had to decide whether the second interval was shorter or longer than a standard (target) interval. Each interval was defined as the silent duration between two successive brief tones. Eight target intervals were used, ranging from 100 to 1,200 ms in duration. At each target interval, the differential threshold (DL) for duration was assessed, with the use of an adaptive psychophysical procedure. The results show that E.C.'s differential threshold values were much larger than those of controls. Moreover, the slope estimates covering the duration range from 100 to 800 ms indicated that in comparison to controls, E.C.'s differential threshold increased dramatically as the target duration increased. Thus her timing impairment becomes more pronounced with increasing duration. This timing deficit is consistent with other studies that have found temporal processing deficits associated with dyslexia.     

The effects of interval duration on temporal tracking and alternation learning

On cyclic-interval reinforcement schedules, animals typically show a postreinforcement pause that is a function of the immediately preceding time interval (temporal tracking). Animals, however, do not track single-alternation schedules-when two different intervals are presented in strict alternation on successive trials. In this experiment, pigeons were first trained with a cyclic schedule consisting of alternating blocks of 12 short intervals (5 s or 30 s) and 12 long intervals (180 s), followed by three different single-alternation interval schedules: (a) 30 s and 180 s, (b) 5 s and 180 s, and (c) 5 s and 30 s. Pigeons tracked both schedules with alternating blocks of 12 intervals. With the single-alternation schedules, when the short interval duration was 5 s, regardless of the duration of the longer interval, pigeons learned the alternation pattern, and their pause anticipated the upcoming interval. When the shorter interval was 30 s, even when the ratio of short to long intervals was kept at 6:1, pigeons did not initially show anticipatory pausing-a violation of the principle of timescale invariance.     

Ordinal properties of perceived average duration: simultaneous and sequential presentations

When a subject evaluates the duration of two simultaneous events, the perceived durations are combined in a nonlinear manner, whereas comparable evaluations of successive events yield linear combinations. Fifty-four subjects rated average durations of pairs of time intervals ranging from 0.5 s to 10.0 s. The intervals making up a pair were presented successively and simultaneously on separate occasions within the same presentation sequence. The order of data was consistent with models previously proposed for perceived average duration. A nonmetric analysis of the combined ordinal data from both conditions yielded a single set of measures of perceived duration with ratio-scale properties. The common scale for the two conditions is consistent with differences in results from simultaneous and successive monitoring of time intervals, stemming from differences in the way duration information is combined rather than how it is perceived. the derived scale is related to physical time by a power function with a 1.06 exponent.     

The effects of type of interval,sensory modality,base duration,and psychophysical task on the discrimination of brief time intervals

The present study was designed to investigate the influences of type of psychophysical task (two-alternative forced-choice [2AFC] and reminder tasks), type of interval (filled vs. empty), sensory modality (auditory vs. visual), and base duration (ranging from 100 through 1,000 ms) on performance on duration discrimination. All of these factors were systematically varied in an experiment comprising 192 participants. This approach allowed for obtaining information not only on the general (main) effect of each factor alone, but also on the functional interplay and mutual interactions of some or all of these factors combined. Temporal sensitivity was markedly higher for auditory than for visual intervals, as well as for the reminder relative to the 2AFC task. With regard to base duration, discrimination performance deteriorated with decreasing base durations for intervals below 400 ms, whereas longer intervals were not affected. No indication emerged that overall performance on duration discrimination was influenced by the type of interval, and only two significant interactions were apparent: Base Duration × Type of Interval and Base Duration × Sensory Modality. With filled intervals, the deteriorating effect of base duration was limited to very brief base durations, not exceeding 100 ms, whereas with empty intervals, temporal discriminability was also affected for the 200-ms base duration. Similarly, the performance decrement observed with visual relative to auditory intervals increased with decreasing base durations. These findings suggest that type of task, sensory modality, and base duration represent largely independent sources of variance for performance on duration discrimination that can be accounted for by distinct nontemporal mechanisms.     

Markers’ influence on the duration discrimination of intermodal intervals

The effects of sensory signal characteristics on the duration discrimination of intermodal intervals was investigated in three experiments. Temporal intervals were marked by either the successive presentation of a visual then auditory signal (VA), or by the successive presentation of an auditory then visual signal (AV). The results indicated that (1) VA intervals are generally easier to discriminate than are AV intervals, but this effect depends on the range of duration studied; (2) AV intervals are perceived as longer than VA intervals for durations ranging from 250 to 750 msec; (3) the intensity of the visual markers for both AV and VA intervals does not affect the discrimination; and (4) the perceived duration of an intermodal interval is influenced by the length of the first and second markers. The results are mainly interpreted in terms of (1) a sensory trace left by visual and auditory signals and (2) the detection of these signals.     

Effects of temporal shapes of sound markers on the perception of interonset time intervals

This study investigated how the temporal characteristics, particularly durations, of sounds affect the perceived duration of very short interonset time intervals (120-360?ms), which is important for rhythm perception in speech and music. In four experiments, the subjective duration of single time intervals marked by two sounds was measured utilizing the method of adjustment, while the markers' durations, amplitude difference (which accompanied the duration change), and sound energy distribution in time were varied. Lengthening the duration of the second marker in the range of 20-100?ms increased the subjective duration of the time interval in a stable manner. Lengthening the first marker tended to increase the subjective duration, but unstably; an opposite effect sometimes appeared for the shortest time interval of 120?ms. The effects of varying the amplitude and the sound energy distribution in time of either marker were very small in the present experimental conditions, thus proving the effects of marker durations per se.     

Tempo sensitivity in isochronous tone sequences: the multiple-look model revisited

Factors affecting tempo sensitivity in isochronous tone sequences were investigated in two experiments. Participants listened to tones in sequence conditions in which the number of time intervals in isochronous standard and comparison sequences was varied, and they were asked to judge the tempo of the comparison relative to the standard. When the duration of the standard interval was held constant, tempo sensitivity was affected by the number of comparison intervals, but not by the number of standard intervals. In contrast, when the duration of the standard interval was varied randomly from trial to trial, tempo sensitivity was affected by the number of intervals in both sequences. The present findings are discussed in the context of a generalized multiple-look model that posits independent contributions of both sequences to tempo sensitivity. Quantitative model fits suggest that the relative contribution of the number of the standard intervals to tempo thresholds depends on (1) the availability of a stable long-term referent for the standard tempo and (2) a priori knowledge about the number of standard intervals.     

Pace alteration and estimation of time intervals

This experiment examined the effects on participants' estimates of interval duration of altering the pace of auditory stimuli contained within "filled" intervals. Because most previous studies on the filled interval effect have utilized visual displays, auditory stimuli were used to assess whether the effect would be present. In addition, previous studies compared two intervals, one of which was filled and the other unfilled. In the present study, both intervals were filled with tones at one of three rates (or "paces"): slow, medium, or fast. 25 participants (20 women) ages 18 to 29 years (M = 20.4, SD = 2.3) were recruited from psychology courses and programs. Participants first heard a "training" interval filled with tones at one of the three paces and then attempted to reproduce the duration of that training interval in the "test" interval. The pace of stimuli in each pair of training and test intervals was varied so participants received all possible combinations of paces of auditory stimuli during the training and test trial sets. Analysis showed that, when training pace was fast and test pace was medium or slow, participants' estimates were longer than the actual test interval durations. Conversely, when training pace was slow and test pace was medium or fast, participants' estimates were shorter than actual test interval durations. In addition, when judging shorter intervals, participants estimated more time had passed than actually had, while they estimated that less time had passed than actually had for longer intervals, thus providing support for Vierordt's law.     

Duration judgment and the segmentation of experience

Two experiments tested an interval segmentation explanation of duration judgment. In Experiment 1, a 170-sec time interval was filled with 27 unrelated words and three high-priority events (HPEs). These HPEs were clustered at the beginning of the interval (unsegmented condition) or distributed throughout the interval (segmented condition). Both recognition and recall of list information were measured, in addition to duration estimates. While no differences in memory performance were found, duration estimates were greater in the the segmented condition. Experiment 2 also tested the effects of interval segmentation but used 36 words and eight HPEs, a longer clock duration, and also measured the remembered number of events (RNE) in the interval. As in Experiment 1, the segmented condition produced longer duration estimates in the absence of memory performance and RNE differences. A segmentation hypothesis seems a better explanation of these results than previously proposed storage size or amount-of-processing models of duration judgment.