The subjective tempo difference between interaural and monaural sequences as a function of sequence length

Previous research has demonstrated that the subjective tempo of sequences of clicks that alternate between ears is slower than that of nonalternating sequences. Although the stimulus onset asynchronies (SOAs) between the clicks are the same in both conditions, their perceptual onset asynchronies (POAs) differ by 25 msec at all SOA values between 40 and 2,130 msec. It has been suggested that this subjective tempo difference originates only after a few clicks have been processed. The present study shows this not to be the case: The POA difference between interaural and monaural click sequences could also be established with sequences comprising only a few clicks.     

Perception of clicks in music

Subjects were asked to judge the position of a click that occurred during a short piece of music. Clicks were, on average, judged to be later than their actual position. The click and the music were presented through headphones to different ears, and the clicks were judged to be significantly later if they arrived at the right ear rather than at the left. There was also a significant tendency for clicks to be attracted to phrase boundaries in the music. These last two results are similar to those from experiments with a click during speech, but the late judgments of a click in music contrast with the early judgments of a click in speech.     

多目标觉知范式检验视觉意识容量

采用一种新的多目标觉知范式检验视觉意识容量。实验中首先迅速呈现包含8个刺激的圆形阵列(刺激位置随机分布), 然后所有刺激被灰色的圆覆盖, 并随机选取阵列中的一个刺激作为目标, 要求被试用尽可能少的点击次数找到目标。结果发现, 即使被试不能一次击中目标, 其也可能拥有对目标不精确的视觉信息。这些不精确的视觉信息能够帮助被试用更少的点击次数和更短的点击距离找到目标, 且被试对这些不精确的视觉信息是有意识的。研究结果表明视觉意识能够以概率性的表征存在, 并支持视觉整体统计假说, 也能够进一步解释视觉意识容量的主观测量和客观测量之间存在的冲突。     

Effect of click rate and delay on breakdown of the precedence effect

The precedence effect was tested as a function of echo-click delay and click rate after an abrupt switch in location between leading and lagging clicks. Click trains at three rates, 1/sec, 2/sec, and 4/sec, with delays ranging between 2 and 20 msec, were presented to subjects in an anechoic chamber. Duration of the click train after the switch in location was 12 sec, and echo click perceptibility was assessed throughout this period. The number of echo clicks heard was an increasing monotonic function of delay. The subjects reported a "fade-out" of echo clicks after a set number of clicks at each delay, regardless of rate. This result was interpreted as a buildup in inhibition of echoes produced by the ongoing click train. Suppression of echoes was stronger when the leading click originated from the right side than from the left side.     

Discrimination of auditory temporal patterns

Two same-different discrimination experiments were performed for click patterns having a total duration of about 4 sec and interclick intervals ofn × 250 msec, withn a random integer. In Experiment 1, the influence of the physical click group structure on discrimination performance was investigated. In Experiment 2, the effect of the strength of an induced internal clock on discrimination performance was measured. Performance was poor if the group structure of clicks was maintained during a change in click pattern and also if the induced infernal clack strength was low. The performance of about 70% of the subjects improved significantly if either a change in click grouping structure occurred or a strong internal clock could be induced. These results cannot be accounted for with simple models based an single-interval duration discrimination or between-pattern correlation statistics.     

Response bias and judgments of the location of clicks in sentences

This study examines the view that response bias is the basis of the “click effect,” i.e., the influence of grammatical structure on subjects’ location of clicks sounded during the presentation of a sentence. It is argued that, since response bias is more likely to operate when one is unsure of one’s perception, if response bias generates the “click effect,” the effect should be weaker for certain than for uncertain responses. Subjects were asked to identify the location of the click and allowed to make more than one response if they were uncertain of their first choice. Using the number of locations selected as an index of uncertainty, it was found that when a subject was less certain, the click was less likely to be judged as having occurred in the major grammatical break. Further, performance was superior when the click had been in the break, and this effect, which was more pronounced for “certain” responses, was not eliminated by correcting for possible response bias. It is concluded that the "click effect" is not attributable solely to response bias.     

Brain stem electrical responses of stutterers and normals by sex,ears, and recovery

Auditory brainstem electrical responses (BSER) of right and left ears of active stutterers, recovered stutterers, and nonstutterers, both male and female adults, were obtained at click rates of 11.1 and 71.1/sec. Latency intervals of waves I, III, and V were measured. The auditory systems of subjects were stressed using a rapid rate of 71.1 clicks/sec. The latency of wave V was used as the measure of the stress condition.Analysis of variance was used to determine statistical significances of main effects and interactions of mean BSER (waves I, III, V, and wave V in stress condition) of left and right ears of male stutterers (active and recovered), female stutterers (active and recovered), and male and female nonstutterers.With one exception, all main effects and all higher order interactions were nonsignificant. The one main effect that was significant was gender. Females have significantly faster rates of neural transmission than do males. The question was raised, does this finding contribute toward an explanation of the sex ratio in stuttering?     

The detection of anisochrony in monaural and interaural sound sequences

Nakao and Axelrod (1976) and van Noorden (1975) showed that the threshold for discriminating an anisochronous duple rhythm (a series of clicks with a temporal offset on every other one) from an isochronous rhythm (no offset) is poorer when the clicks are presented alternately to the two ears than when they are presented to the same ears. Van Noorden reported that the difference between the thresholds in the alternating and nonalternating conditions varied with the tempo of the sequence. Nakao and Axelrod found invariance of this threshold difference with sequence speed. According to our quantification of temporal processing of interaural sequences, the latter result should be expected. We carried out five psychophysical experiments to establish interaural and monaural discrimination between isochronous and anisochronous rhythms. Across experiments, base time intervals of 60–720 msec were spanned. The main result was that we replicated the poorer discrimination for interaural sequences. This deterioration in discrimination was the same for all sequence speeds. It was also the case that the thresholds were almost constant up to a sound repetition rate of about 3 per second, but increased linearly with slower rates. This result supports evidence in the literature that temporal processing of sequences faster than about 3–4 sounds per second differs from temporal processing of slower sequences.     

Effect of click trains on duration estimates by people with Parkinson's disease

Patients with a diagnosis of Parkinson's disease and age- and IQ-matched controls estimated the duration of short 500-Hz tones (325–1,225 ms), on trials where the tone was either preceded by 3 s of 5-Hz clicks, or presented without clicks. The click manipulation had been shown in earlier studies with student participants to make verbal estimates longer. Patients were tested both on and off their dopaminergic medication, and controls were also tested in two sessions. Verbal estimates were markedly and significantly longer on trials with clicks than on those without clicks for both the patients and the controls, but there were no significant performance differences between patients or controls, nor between the on and off medication sessions in the patients. The study shows that a manipulation of subjective time, which has had small but consistent effects in student participants, also affects timing in patients and adds to a growing body of evidence that timing in patients with Parkinson's disease may in many cases have the same characteristics as those of neurologically intact control groups.     

Syntactic structure modifies attention during speech perception and recognition

The present paper demonstrates the interaction of syntactic structure and speech perception with a response task which minimizes the effects of memory: reaction time (RT) to clicks during sentences. (1) In 12-word unfamiliar sentences each with two clauses, RT is relatively slow overall to clicks located at the end of the first clause but decreases as a function of clause length. Clicks at the beginning of the second clause are not affected by length of the preceding clause. (2) In familiar sentences, RT is relatively fast to clicks located at the end of a clause while RT to clicks at the beginning of clauses is relatively unaffected by familiarity. (3) RT is not fastest overall to clicks located between clauses either in novel or familiar sentences. (4) As in previous studies, the subject's subsequent judegment of the location of the click tone are towards the clause break. (5) We could find no systematic interaction between RT and subjective click location. Findings (1) to (3) are consistent with the view that perceptual processing alternates between attending to all external stimuli and developing an internal representation of the stimuli. Finding (3) is in conflict with an “information channel” view of immediate attention to speech, which would predict high sensory attention to non-speech stimuli between clauses. However, findings (4) and (5) indicate that the channel view of perception may be correct for that perceptual processing which occurs after the immediate organization of the speech stimulus into major segments.     

Synchronizing actions with events: The role of sensory information

Tasks requiring the subject to tap in synchrony to a regular sequence of stimulus events (e.g., clicks) usually elicit a response pattern in which the tap precedes the click by about 30-50 msec. This “negative asynchrony” was examined, first, by instructing subjects to use different effectors for tapping (hand vs. foot; Experiments 1 and 2), and second, by administering extrinsic auditory feedback in addition to the intrinsic tactile/kinesthetic feedback (Experiment 2). Experiment 3 controlled whether the results observed in Experiment 2 were due to purely sensory factors within the auditory modality. Results suggest that taps are synchronized with clicks at the central level by superimposing two sensory codes in time: the tactile/kinesthetic code that represents the tap (the afferent movement code) and the auditory code that represents the click (the afferent code that results from the guiding signal). Because the processing times involved in code generation are different for these two central codes, the tap has to lead over the click.     

Counting in sign language

Do the visuomanual modality and the structure of the sequence of numbers in sign language have an impact on the development of counting and its use by deaf children? The sequence of number signs in Belgian French Sign Language follows a base-5 rule while the number sequence in oral French follows a base-10 rule. The accuracy and use of sequence number string were investigated in hearing children varying in age from 3 years 4 months to 5 years 8 months and in deaf children varying in age from 4 years to 6 years 2 months. Three tasks were used: abstract counting, object counting, and creation of sets of a given cardinality. Deaf children exhibited age-related lags in their knowledge of the number sequence; they made different errors from those of hearing children, reflecting the rule-bound nature of sign language. Remarkably, their performance in object counting and creating sets of given cardinality was similar to that of hearing children who had a longer sequence number string, indicating a better use of counting than predicted by their knowledge of the linguistic sequence of numbers.     

Computer‐assisted learning for adults with profound multiple disabilities

Five adults with profound physical and intellectual disabilities were taught to respond to photographs of preferences embedded in Microsoft PowerPoint (Microsoft, 1997 ) presentations by operating microswitches that functioned as mouse clicks. Rate of responding was generally correlated with changes in types of presentation, although variability in rate was often high, and session durations were quite short. Two participants showed substantial increases in responding when fitted with switches that were easier to manipulate. This exploratory study demonstrates that people with extremely limited physical and cognitive abilities can be taught to operate switches that produce changes in visual arrays on a computer screen and sometimes differentially so. Implications for responding to photographic representations of preferences, rather than the tangible preferences themselves, are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

Effect of click trains on duration estimates by people with Parkinson's disease

Patients with a diagnosis of Parkinson's disease and age- and IQ-matched controls estimated the duration of short 500-Hz tones (325-1,225 ms), on trials where the tone was either preceded by 3 s of 5-Hz clicks, or presented without clicks. The click manipulation had been shown in earlier studies with student participants to make verbal estimates longer. Patients were tested both on and off their dopaminergic medication, and controls were also tested in two sessions. Verbal estimates were markedly and significantly longer on trials with clicks than on those without clicks for both the patients and the controls, but there were no significant performance differences between patients or controls, nor between the on and off medication sessions in the patients. The study shows that a manipulation of subjective time, which has had small but consistent effects in student participants, also affects timing in patients and adds to a growing body of evidence that timing in patients with Parkinson's disease may in many cases have the same characteristics as those of neurologically intact control groups.     

Click location and syntactic structure

Four experiments are reported in which Ss had to judge the location of clicks superimposed on recorded sentences. The first experiment showed that the accuracy of locating the clicks was a function of the position of the click in the constituent structure, the greatest accuracy being for clicks at major clause boundaries. The second experiment showed that this effect was independent of migration, i.e., the tendency for judgments to be displaced towards the major clause break. In the third experiment, it was shown that the requirement that S reproduce the sentence did not influence the response distribution. Finally, in the fourth experiment, a small but significant trend for location accuracy to decrease with decreasing separation of the click from the major break was found. However, this trend was much smaller than the differences in accuracy for various positions in the constituent structure. It was concluded that click location accuracy can be used as an index of perceptual processing load during recognition of individual sentences.     

Control of Expressive and Metronomic Timing in Pianists

In 12 tasks, each including 10 repetitions, 6 skilled pianists performed or responded to a musical excerpt. In the first 6 tasks, expressive timing was required; in the last 6 tasks, metronomic timing. The pianists first played the music on a digital piano (Tasks 1 and 7), then played it without auditory feedback (Tasks 2 and 8), then tapped on a response key in synchrony with one of their own performances (Tasks 3 and 9), with an imagined performance (Tasks 4 and 10), with a computer-generated performance (Tasks 5 and 11), and with a computer-generated sequence of clicks (Tasks 6 and 12). The results demonstrated that pianists are capable of generating the expressive timing pattern of their performance in the absence of auditory and kinaesthetic (piano keyboard) feedback. They can also synchronize their finger taps quite well with expressively timed music or clicks (while imagining the music), although they tend to underestimate long interonset intervals and to compensate on the following tap. Expressive timing is thus shown to be generated from an internal representation of the music. In metronomic performance, residual expressive timing effects were evident. Those did not depend on auditory feedback, but they were much reduced or absent when kinaesthetic feedback from the piano keyboard was eliminated. Thus, they seemed to arise from the pianist's physical interaction with the instrument. Systematic timing patterns related to expressive timing were also observed in synchronization with a metronomic computer performance and even in synchronization with metronomic clicks. These results shed light on intentional and unintentional, structurally governed processes of timing control in music performance.     

Click monitoring revisited: An on-line study of sentence comprehension

Spoken sentence comprehension is based upon rapid and complex psychological processes, yielding a constantly fluctuating cognitive load. The aim of this study was to evaluate on-line click monitoring, a classical but poorly exploited experimental method, which should allow for an easy measurement of processing load at any chosen point of experimental sentences. In Experiments 1 and 2, we obtained longer latencies to clicks located at the boundary of reversible object relative clauses than to clicks identically located in subject relatives and to clicks located earlier within object relatives. Experiment 3 further revealed that this effect of syntactic type was specific to transposed object relatives and did not occur with normal object relatives. In Experiment 4, we observed longer latencies with semantically reversible than with irreversible sentences, but no difference between actives and passives. These results were obtained under strict control of potential lexical and phonological biases, and suggest that on-line click monitoring may be one useful tool in the study of sentence comprehension.     

The internal clock: Electroencephalographic evidence for oscillatory processes underlying time perception

It has been proposed that temporal perception and performance depend on a biological source of temporal information. A model for a temporal oscillator put forward by Treisman, Faulkner, Naish, and Brogan (1990) predicted that if intense sensory pulses (such as auditory clicks) were presented to subjects at suitable rates they would perturb the frequency at which the temporal oscillator runs and so cause over- or underestimation of time. The resulting pattern of interference between sensory pulse rates and time judgments would depend on the frequency of the temporal oscillator and so might allow that frequency to be estimated. Such interference patterns were found using auditory clicks and visual flicker (Treisman & Brogan, 1992; Treisman et al., 1990). The present study examines time estimation together with the simultaneously recorded electroencephalogram to examine whether evidence of such an interference pattern can be found in the EEG.

Alternative models for the organization of a temporal system consisting of an oscillator or multiple oscillators are considered and predictions derived from them relating to the EEG. An experiment was run in which time intervals were presented for estimation, auditory clicks being given during those intervals, and the EEG was recorded concurrently. Analyses of the EEG revealed interactions between auditory click rates and certain EEG components which parallel the interference patterns previously found. The overall pattern of EEG results is interpreted as favouring a model for the organization of the temporal system in which sets of click-sensitive oscillators spaced at intervals of about 12.8 Hz contribute to the EEG spectrum. These are taken to represent a series of harmonically spaced distributions of oscillators involved in time-keeping.     

Effects of location, frequency region, and time course of selective attention on auditory scene analysis

Often, the sound arriving at the ears is a mixture from many different sources, but only 1 is of interest. To assist with selection, the auditory system structures the incoming input into streams, each of which ideally corresponds to a single source. Some authors have argued that this process of streaming is automatic and invariant, but recent evidence suggests it is affected by attention. In Experiments 1 and 2, it is shown that the effect of attention is not a general suppression of streaming on an unattended side of the ascending auditory pathway or in unattended frequency regions. Experiments 3 and 4 investigate the effect on streaming of physical gaps in the sequence and of brief switches in attention away from a sequence. The results demonstrate that after even short gaps or brief switches in attention, streaming is reset. The implications are discussed, and a hierarchical decomposition model is proposed.