Perceiving temporal regularity in music

We address how listeners perceive temporal regularity in music performances, which are rich in temporal irregularities. A computational model is described in which a small system of internal self‐sustained oscillations, operating at different periods with specific phase and period relations, entrains to the rhythms of music performances. Based on temporal expectancies embodied by the oscillations, the model predicts the categorization of temporally changing event intervals into discrete metrical categories, as well as the perceptual salience of deviations from these categories. The model's predictions are tested in two experiments using piano performances of the same music with different phrase structure interpretations (Experiment 1) or different melodic interpretations (Experiment 2). The model successfully tracked temporal regularity amidst the temporal fluctuations found in the performances. The model's sensitivity to performed deviations from its temporal expectations compared favorably with the performers' structural (phrasal and melodic) intentions. Furthermore, the model tracked normal performances (with increased temporal variability) better than performances in which temporal fluctuations associated with individual voices were removed (with decreased variability). The small, systematic temporal irregularities characteristic of human performances (chord asynchronies) improved tracking, but randomly generated temporal irregularities did not. These findings suggest that perception of temporal regularity in complex musical sequences is based on temporal expectancies that adapt in response to temporally fluctuating input.     

Associative, bidirectional changes in neural signaling utilizing NMDA receptor- and endocannabinoid-dependent mechanisms

Persistent, bidirectional changes in synaptic signaling (that is, potentiation and depression of the synapse) can be induced by the precise timing of individual pre- and postsynaptic action potentials. However, far less attention has been paid to the ability of paired trains of action potentials to elicit persistent potentiation or depression. We examined plasticity following the pairing of spike trains in the touch mechanosensory neuron (T cell) and S interneuron (S cell) in the medicinal leech. Long-term potentiation (LTP) of T to S signaling was elicited when the T-cell spike train preceded the S-cell train. An interval 0 to +1 sec between the T- and S-cell spike trains was required to elicit long-term potentiation (LTP), and this potentiation was NMDA receptor (NMDAR)-dependent. Long-term depression (LTD) was elicited when S-cell activity preceded T-cell activity and the interval between the two spike trains was -0.2 sec to -10 sec. This surprisingly broad temporal window involved two distinct cellular mechanisms; an NMDAR-mediated LTD (NMDAR-LTD) when the pairing interval was relatively brief (<-1 sec) and an endocannabinoid-mediated LTD (eCB-LTD) when longer pairing intervals were used (-1 to -10 sec). This eCB-LTD also required activation of a presynaptic transient receptor potential vanilloid (TRPV)-like receptor, presynaptic Ca(2+) release from intracellular stores and activation of voltage-gated Ca(2+) channels (VGCCs). These findings demonstrate that the pairing of spike trains elicits timing-dependent forms of LTP and LTD that are supported by a complex set of cellular mechanisms involving NMDARs and endocannabinoid activation of TRPV-like receptors.     

Further studies on the psychophysics of irregular nerve action potential patterns

In this paper we consider two problems concerning human psychophysical discriminability of variable interval nerve action potential patterns. The first question asks which of two possible alternatives-additional sample size or elongation of duration-is responsible for the improvement in performance as the number of pulses in a stimulus train increases. Our data strongly indicated that the answer to this question is increased sample size. The second question concerns what effect, if any, parallel rather than serial presentation of the two alternatives in a forced choice psychophysical test will have on the function relating interpulse interval and discriminability. The answer to this question appears to be that other than a slight elevation of the absolute levels no changes in the general form of the response is produced.     

Bias and learning in temporal binding: Intervals between actions and outcomes are compressed by prior bias

It has consistently been shown that agents judge the intervals between their actions and outcomes as compressed in time, an effect named intentional binding. In the present work, we investigated whether this effect is result of prior bias volunteers have about the timing of the consequences of their actions, or if it is due to learning that occurs during the experimental session. Volunteers made temporal estimates of the interval between their action and target onset (Action conditions), or between two events (No-Action conditions). Our results show that temporal estimates become shorter throughout each experimental block in both conditions. Moreover, we found that observers judged intervals between action and outcomes as shorter even in very early trials of each block. To quantify the decrease of temporal judgments in experimental blocks, exponential functions were fitted to participants’ temporal judgments. The fitted parameters suggest that observers had different prior biases as to intervals between events in which action was involved. These findings suggest that prior bias might play a more important role in this effect than calibration-type learning processes.     

Simulation of the response of a multichannel nerve array to pulse shapes produced by single-channel electrostimulation

Results of experiments on single-channel electrostimulation of the cochlea which throw light on the performance of the central auditory nervous system (CANS) have recently been reported by Dobie and Dillier. Trains of pulses with different rise times could be distinguished by subjects with cochlea implants, even though time differences involved were very small. It was suggested by the authors that the information is carried to the CANS by an array of nerve fibres with characteristic time differences. In the present paper, simulations produced by means of a nerve model are reported and used to compute the patterns of action potentials evoked on the nerve array by different pulse trains. The changes in the patterns of the nerve responses resulting from the shape variations which have to be perceived by the CANS are examined.     

Distinctiveness revisited: Unpredictable temporal isolation does not benefit short-term serial recall of heard or seen events

The notion of a link between time and memory is intuitively appealing and forms the core assumption of temporal distinctiveness models. Distinctiveness models predict that items that are temporally isolated from their neighbors at presentation should be recalled better than items that are temporally crowded. By contrast, event-based theories consider time to be incidental to the processes that govern memory, and such theories would not imply a temporal isolation advantage unless participants engaged in a consolidation process (e.g., rehearsal or selective encoding) that exploited the temporal structure of the list. In this report, we examine two studies that assessed the effect of temporal distinctiveness on memory, using auditory (Experiment 1) and auditory and visual (Experiment 2) presentation with unpredictably varying interitem intervals. The results show that with unpredictable intervals temporal isolation does not benefit memory, regardless of presentation modality.     

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。     

Temporal coordination between actions and sound during sequence production

Delayed auditory feedback (DAF) causes asynchronies between perception and action that disrupt sequence production. Different delay lengths cause differing amounts of disruption that may reflect the phase location of feedback onsets relative to produced inter-response intervals, or the absolute temporal separation between actions and sounds. Two experiments addressed this issue by comparing the effects of traditional DAF, which uses a constant temporal separation, with delays that adjust temporal separation to maintain the phase location of feedback onsets within inter-response intervals. Participants played simple isochronous melodies on a keyboard, or tapped an isochronous beat, at three production rates. Disruption was best predicted by the phase location of feedback onsets, and diminished when feedback onsets formed harmonic phase ratios (phase synchrony). Both delay types led to similar effects. Different movement tasks (melody production versus tapping) led to slightly different patterns of disruption across phase that may relate to differing task demands. In general, these results support the view that perception and action are coordinated in relative rather than absolute time.     

Temporal control and coordination: the multiple timer model.

We consider the psychological and neurological mechanisms involved in timed behaviors, motor or perceptual tasks that emphasize the temporal relationship between successive events. Two general models for representing temporal information are described. In one model, temporal information is based on the oscillatory activity of an endogenous pacemaker; in the other model, temporal information is interval-based with distinct elements devoted to representing different intervals. We incorporate the interval hypothesis into a process model, the multiple timer model, to account for the timing and coordination of repetitive movements. The model accounts for the patterns of temporal stability observed within each effector and offers a novel account of between-effector coordination. Finally, we consider how timing and temporal coordination may be instantiated in the nervous system.     

Discrimination of stimulus aperiodicity as a function of temporal patterning: a discrepancy between psychophysical and sensory-neural assessments.

Tactile discrimination of stimulus aperiodicity was investigated in a two-alternative forced-choice task by having subjects report which of two successively presented trains of mechanical pulses, one with complete pulse periodicity and one in which a single pulse was temporally displaced from its regular placement, was temporally irregular or aperiodic. Trains contained three, four, or five pulses and were presented at interpulse intervals of 60, 75, 85, 100, 125, and 150 ms. Aperiodic trains had one pulse, other than the first or last pulse, temporally advanced or receded by 40% of the interstimulus interval. Results showed that: (i) although the percentage of correct reports of aperiodicity decreased as presentation rate increased (smaller interpulse intervals), the amount of decrease was a function of the number of pulses in a train; (ii) the discrimination of aperiodicity was dependent upon the specific location of the irregularity within the stimulus temporal pattern; and (iii) all patterns with complete temporal reversals of their successive interpulse intervals yielded nearly equivalently accurate reports of aperiodicity. These data suggest that central, attentional factors are involved in the discrimination of stimulus aperiodicity.     

Dynamics of time discrimination: II. The effects of multiple impulses.

According to a diffusion generalization model, time discrimination is determined by the frequency and recency of preceding intervals of time. A procedure for studying rapid timing was used to investigate whether pigeons' wait-time responses were sensitive to these factors. In Experiment 1 the number (two or eight) and spacing (consecutive or far apart) of 5-s interfood intervals (called impulses) intercalated in a series of 15-s interfood intervals (nonimpulses) were studied. Experiment 2 was identical to the first but the interfood intervals were increased by a factor of three. Overall, impulses shortened wait times in the next interfood interval. However, several impulses occurring in succession extended the localized effect of an impulse: Wait times following a set of eight-close impulses were slow to recover to preimpulse levels. The results show that linear waiting is only an approximation to the dynamic process, and a process that is sensitive to events in an animal's remote past, such as the diffusion generalization model, provides a better account of rapid timing effects.     

Short-term memory models for choice behavior

In this paper we consider the effect of imposing memory restrictions on the accumulator and random-walk models of choice behavior outlined by Audley (Psychological Review, 1960, 67, 1–15). Specifically, it is assumed that subjects apply criteria to the numbers of impulses received, and that if the criteria are not satisfied by the time w impulses have been received, then thereafter the criteria are only applied to w impulses, which could, for example, be the last w impulses received. Exact and approximate mathematical approaches and simulation techniques are presented in detail. The results obtained demonstrate that both the restricted accumulator and the restricted random-walk models can make qualitative predictions in line with much recent data.     

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.     

Psychoacoustic evaluation of musical sounds

A review is given of several basic aspects of musical sounds, i.e., the perception of duration, the perception of sound impulses as events within temporal patterns, timbre, the equivalence of sensational intervals, roughness, and the pitch qualities of complex sounds. Selected examples illustrate how psychoacoustic results can contribute to the evaluation of musical sounds and to the understanding of the perception of music.     

Phenomenological Analysis and its Contemporary Significance

Can a phenomenologically-founded sociology contribute to the understanding of social change? By reference to the structure of the lifeworld as it has been analyzed by Husserl and Schutz, I argue that human action is formed by temporal, spatial, and social dimensions. These are objectified by a social semantics through which they gain their intersubjective cultural shape. From this perspective, I investigate changes in the temporal, spatial, and social dimensions of this semantics, as they occur in the present transformation of post-socialist societies. Finally, I consider whether these changes mark a return to Western patterns and whether they confirm the thesis of “the end of history.”     

The effect of ischemia on the peripheral nerve action potential in man and its relation to somatosensory magnitude coding

The amplitude and latency fluctuations of the compound action potential of the ulnar nerve were recorded percutaneously as a function of the length of time the arm was kept ischemic by means of an inflated sphygmomanometer cuff. Changes in latency and the amplitude action potential were measured for cuff positions above and below the recording electrode. The amplitude fluctuations were shown to be related to corresponding changes in the sensory threshold which has been determined in an earlier study. By manipulating the position of the cuff it was possible to determine that the amplitude fluctuations were caused by a reduced number of nerve action potentials rather than a change in the individual atonal action potential amplitude.     

Stability of apparent vertical and ocular countertorsion as a function of lateral tilt

The discrimination of a single temporal discontinuity, or gap, within an auditory pulse train was studied as a function of the relative magnitude of the gap region to its immediately surrounding interpulse intervals (the near surround) and to interpulse intervals flanking the near surround (the far surround). Near-surround effects substantially outweigh far-surround effects.     

Is Semantic Processing During Sentence Reading Autonomous or Controlled? Evidence from the N400 Component in a Dual Task Paradigm

The present study contributes to the discussion on the automaticity of semantic processing. Whereas most previous research investigated semantic processing at word level, the present study addressed semantic processing during sentence reading. A dual task paradigm was combined with the recording of event-related brain potentials. Previous research at word level processing reported different patterns of interference with the N400 by additional tasks: attenuation of amplitude or delay of latency. In the present study, we presented Spanish sentences that were semantically correct or contained a semantic violation in a critical word. At different intervals preceding the critical word a tone was presented that required a high-priority choice response. At short intervals/high temporal overlap between the tasks mean amplitude of the N400 was reduced relative to long intervals/low temporal overlap, but there were no shifts of peak latency. We propose that processing at sentence level exerts a protective effect against the additional task. This is in accord with the attentional sensitization model (Kiefer & Martens, 2010), which suggests that semantic processing is an automatic process that can be enhanced by the currently activated task set. The present experimental sentences also induced a P600, which is taken as an index of integrative processing. Additional task effects are comparable to those in the N400 time window and are briefly discussed.     

I Lost It in the Lights: The Effects of Predictable and Variable Intermittent Vision on Unimanual Catching

In this study, 2 competing views of interceptive action were examined by assessing the influence of variability in the interval between visual samples in a unimanual ball-catching task. Subjects were required to catch tennis balls projected over a distance of 14 m, under conditions of intermittent vision in which the between-sample intervals were either predictable or unpredictable. Results indicated that, although performance was best with shorter between-sample intervals, the temporal predictability of samples did not reliably affect catching performance. This suggests that between-sample retinal expansion provides sufficient information for the timing of the interceptive act.     

Audiovisual tau effect

This study investigated how spatial intervals between successive visual flashes are influenced by the temporal intervals between auditory pure tones presented concurrently with the flashes. Three successive visual flashes defined two spatial intervals with different extents as well as two equal temporal intervals. The onsets of the first and third tones were temporally aligned with those of the first and third flashes, while the onset of the second tone was temporally offset to that of the second visual flash, resulting in shorter or longer temporal intervals between pairs of tones. Observers judged which of the first or second spatial intervals between flashes was shorter. The results showed that the shorter temporal interval between tones caused underestimation of the spatial interval between flashes. On the other hand, stimuli without the first and third tones did not result in underestimation of spatial intervals between flashes. These results indicate an audiovisual tau effect, which is triggered by a constant velocity assumption applied to moving objects defined by more than one modality.