Dissociation of explicit and implicit timing in repetitive tapping and drawing movements.

Four experiments explored the hypothesis that temporal processes may be represented and controlled explicitly or implicitly. Tasks hypothesized to require explicit timing were duration discrimination, tapping, and intermittent circle drawing. In contrast, it was hypothesized that timing control during continuous circle drawing does not rely on an explicit temporal representation; rather, temporal control is an emergent property of other control processes (i.e., timing is controlled implicitly). Temporal consistency on the tapping and intermittent drawing tasks was related, and performance on both of these tasks was correlated with temporal acuity on an auditory duration discrimination task. However, timing variability of these 3 tasks was not correlated with timing variability of continuous circle drawing. These results support the hypothesized distinction between explicit and implicit temporal representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Timing processes are correlated when tasks share a salient event.

Event timing is manifested when participants make discrete movements such as repeatedly tapping a key. Emergent timing is manifested when participants make continuous movements such as repeatedly drawing a circle. Here we pursued the possibility that providing salient perceptual events to mark the completion of time intervals could allow circle drawing and tapping to share a common timing process. Individual differences in timing performance were correlated in the tapping and circle drawing tasks when a salient auditory event marked the completion of a cycle. The results suggest that the distinction between event timing and emergent timing does not inhere solely in kinematics but inheres as well in the way task goals are represented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The costs of taking it slowly: Fast and slow movement timing in older age.

We investigated adult age-differences in timing control of fast vs. slow repetitive movements using a dual-task approach. Twenty-two young (M = 24.23 yr) and 22 older adults (M = 66.64 yr) performed three cognitive tasks differing in working memory load and response production demands and they tapped series of 550-ms or 2100-ms target intervals. Single-task timing was comparable in both groups. Dual-task timing was characterized by shortening of produced intervals and increases in drift and variability. Dual-task costs for both cognitive and timing performances were pronounced at slower tapping tempos, an effect exacerbated in older adults. Our findings implicate attention and working memory processes as critical components of slow movement timing and sources of specific challenges thereof for older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prefrontal involvement in "temporal bridging" and timing movement

Brain activity exclusively related to a temporal delay has rarely been investigated using modern brain imaging. In this study we exploited the temporal resolution of functional magnetic resonance imaging (fMRI) to characterise, by sinusoidal regression analysis, differential neuroactivation patterns induced in healthy subjects by two sensorimotor synchronization tasks different in their premovement delay of either 0.6 s or 5 s. The short event rate condition required rhythmic tapping, while the long event rate condition required timing of intermittent movements. Left rostral prefrontal cortex, medial frontal cortex, SMA and supramarginal gyrus demonstrated increased MR signal intensity during low frequency synchronization, suggesting that these brain regions form a distributed neural network for cognitive time management processes, such as time estimation and motor output timing. Medial frontal cortex showed a biphasic pattern of response during both synchronization conditions, presumably reflecting frequency-independent motor output related attention. As predicted, sensorimotor and visual association areas demonstrated increased MR signal intensity during high frequency synchronization.     

Perception and production of temporal intervals across a range of durations: Evidence for a common timing mechanism.

Study participants performed time perception and production tasks over a set of 4 intervals ranging from 325 to 550 ms. In 3 experiments, variability on both the production and perception tasks was found to be linearly related to the square of the target intervals. If the perception and production of short temporal intervals use a common timing mechanism, the slopes of the functions for the 2 tasks should be identical. The results of Experiment 1 failed to support this prediction. However, when the 2 tasks were made more similar by providing a single (Experiment 2) or multiple (Experiment 3) presentations of the target interval per judgment or production, the perception and production functions were nearly identical. The results suggest that temporal judgments and productions are based on an integrated internal representation of the target interval rather than reference to an internal oscillatory process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal processing in the basal ganglia.

This study investigated the role of the basal ganglia in timing operations. Nondemented, medicated Parkinson's disease (PD) patients and controls were tested on 2 motor-timing tasks (paced finger tapping at a 300- or 600-ms target interval), 2 time perception tasks (duration perception wherein the interval between the standard tone pair was 300 or 600 ms), and 2 tasks that controlled for the auditory processing (frequency perception) demands of the time perception task and the movement rate (rapid tapping) in the motor-timing task. Using A. M. Wing and A. B. Kristofferson's (1973) model, the total variability in motor timing was partitioned into a clock component, which reflects central timekeeping operations, and a motor delay component, which estimates random variability due to response implementation processes. The PD group was impaired at both target intervals of the time perception and motor-timing tasks. Impaired motor timing was due to elevated clock but not motor delay variability. The findings implicate the basal ganglia and its thalamocortical connections in timing operations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional resources in timing: interference effects in concurrent temporal and nontemporal working memory tasks

Three experiments examined interference effects in concurrent temporal and nontemporal tasks. The timing task in each experiment required subjects to generate a series of 2- or 5-sec temporal productions. The nontemporal tasks were pursuit rotor tracking (Experiment 1), visual search (Experiment 2), and mental arithmetic (Experiment 3). Each nontemporal task had two levels of difficulty. All tasks were performed under both single- and dual-task conditions. A simple attentional allocation model predicts bidirectional interference between concurrent tasks. The main results showed the classic interference effect in timing. That is, the concurrent nontemporal tasks caused temporal productions to become longer (longer productions represent a shortening of perceived time) and/or more variable than did timing-only conditions. In general, the difficult version of each nontemporal task disrupted timing more than the easier version. The timing data also exhibited a serial lengthening effect, in which temporal productions became longer across trials. Nontemporal task performance showed a mixed pattern. Tracking and visual search were essentially unaffected by the addition of a timing task, whereas mental arithmetic was disrupted by concurrent timing. These results call for a modification of the attentional allocation model to incorporate the idea of specialized processing resources. Two major theoretical frameworks--multiple resource theory and the working memory model--are critically evaluated with respect to the resource demands of timing and temporal/nontemporal dual-task performance.     

Cognitive resources and dual-task interference effects at retrieval in normal people: The role of the frontal lobes and medial temporal cortex.

Conducted 3 experiments to examine the hypothesis that concurrent secondary tasks at retrieval will interfere more with long-term, episodic memory functions involving the frontal lobes than those involving the medial temporal lobes hippocampus (MTL/H). The rationale is that strategic retrieval processes mediated by the frontal lobes place greater demands on cognitive resources than do relatively automatic associative retrieval processes (ecphory) mediated by the temporal lobes. In Exps 1 and 2, sequential finger tapping was performed at encoding, at retrieval, at both, or at neither. Recall of a categorized list of 16 words from the California Verbal Learning Test in Exp 1, and release from proactive inhibition (PI) in Exp 2, both being tests that involve the frontal lobes, were impaired if normal Ss tapped at both encoding and retrieval. Concurrent tapping had little effect on rate of learning in Exp 1 and on total words recalled during the buildup of PI in Exp 2, both of which are indices that are affected more by MTL/H than by frontal lesions. In Exp 3, tapping by normal Ss affected letter fluency, a test more sensitive to frontal lobe than temporal lobe damage, but not category fluency, for which the reverse is true. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The time of our lives: Life span development of timing and event tracking.

Life span developmental profiles were constructed for 305 participants (ages 4-95) for a battery of paced and unpaced perceptual-motor timing tasks that included synchronize-continue tapping at a wide range of target event rates. Two life span hypotheses, derived from an entrainment theory of timing and event tracking, were tested. A preferred period hypothesis predicted a monotonic slowing of a preferred rate (tempo) of event tracking across the life span. An entrainment region hypothesis predicted a quadratic profile in the range of event rates that produced effective timing across the life span; specifically, age-specific entrainment regions should be narrower in childhood and late adulthood than in midlife. Findings across tasks provide converging support for both hypotheses. Implications of these findings are discussed for understanding critical periods in development and age-related slowing of event timing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When two hands are better than one: Reduced timing variability during bimanual movements.

Within-hand variability was reduced on a repetitive tapping task when individuals tapped with 2 hands in comparison to single-handed tapping. When the total variability was decomposed into central timing and peripheral implementation components (A.M. Wing and A.B. Kristofferson; see record 1974-10323-001), the bimanual advantage was attributed to decreased central variability. The improved consistency does not require that the movements involve homologous muscles. However, unlike phase coupling, the bimanual advantage is not found when the 2 movements are produced by different individuals, but rather requires that the 2 movements be produced by 1 individual. It is proposed that separate timing mechanisms are associated with each effector. During bimanual movements, the outputs from these timing mechanisms are integrated prior to movement execution, and it is this integration that results in the bimanual advantage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer of learning among motor patterns with different relative timing.

The generalized motor program concept with invariant relative timing leads one to expect nearly perfect transfer of training to a motor pattern with another duration and considerably less transfer to a pattern with a different relative timing. In two experiments, subjects were asked to learn spatial–temporal patterns of limb action at the elbow. These expectations about differential transfer were examined by the use of two target patterns that differed only by a nonlinear transformation of the time scale. Both experiments failed to provide evidence that transfer breaks down if relative timing is changed. These outcomes are taken to suggest that the often observed invariant relative timing might not be a mandatory phenomenon due to the restriction of a generalized motor program to one particular temporal pattern. Rather, this invariance could perhaps be thought of as a strategic phenomenon caused by preferences for certain temporal organizations contingent upon particular spatial patterns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rhythms and responses.

[Correction Notice: An erratum for this article was reported in Vol 11(5) of Journal of Experimental Psychology: Human Perception and Performance (see record 2008-10975-001). There is a typographical error on page 153. A correction to this error has been provided in the erratum.] Tested the assumption that there is a central clock coordinating behavior in all sensory modalities and response modes. A rhythmic tapping task was used in 3 experiments in which 12 undergraduates first attempted to synchronize responses with brief auditory, tactile, or visual stimuli and then continued to tap at the same rate on their own. Performance was most variable with visual stimuli and least variable with auditory stimuli. Results suggest that performances were not based on a common clock and that different strategies were employed when the task was presented in different modalities. The hypothesis of a single timing mechanism controlling behavior is rejected, and the validity is questioned of information processing models that are formulated without regard to temporal relations among their conjectured processes. Discussion focuses on the relation between successive responses and the means by which timing is accomplished. (56 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Variability in isochronous tapping: Higher order dependencies as a function of intertap interval.

Isochronous serial interval production (ISIP) data, as from unpaced finger tapping, exhibit higher order dependencies (drift). This fact has largely been ignored by the timing literature, one reason probably being that influential timing models assume random variability. Men and women, 22–36 years old, performed a synchronization–continuation task with intertap intervals (ITI) from 0.4 s to 2.2 s. ISIP variability was partitioned into components attributable to drift and 1st-order serial correlation, and the results indicate that (a) drift contributes substantially to the dispersion for longer ITIs, (b) drift and 1st-order correlation are different functions of the ITI, and (c) drift exhibits break close to 1.0 s and 1.4 s ITI. These breaks correspond to qualitative changes in performance for other temporal tasks, which suggests common timing processes across modalities and tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological correlates of early symptoms of autism

Both the medial temporal lobe and dorsolateral prefrontal cortex have been implicated in autism. In the present study, performance on two neuropsychological tasks--one tapping the medial temporal lobe and related limbic structures, and another tapping the dorsolateral prefrontal cortex--was examined in relation to performance on tasks assessing autistic symptoms in young children with autism, and developmentally matched groups of children with Down syndrome or typical development. Autistic symptoms included orienting to social stimuli, immediate and deferred motor imitation, shared attention, responses to emotional stimuli, and symbolic play. Compared with children with Down syndrome and typically developing children, children with autism performed significantly worse on both the medial temporal lobe and dorsolateral prefrontal tasks, and on tasks assessing symptoms domains. For children with autism, the severity of autistic symptoms was strongly and consistently correlated with performance on the medial temporal lobe task, but not the dorsolateral prefrontal task. The hypothesis that autism is related to dysfunction of the medial temporal lobe and related limbic structures, such as the orbital prefrontal cortex, is discussed.     

Auditory feedback in music performance: Evidence for a dissociation of sequencing and timing.

Four experiments examined temporal relationships between actions and auditory feedback in music performance. Experiment 1 incorporated phase shifts of feedback, which disrupted produced timing but not overall accuracy. Experiment 2 incorporated period shifts of pitch contents for synchronized feedback that primarily disrupted accuracy more than timing. Experiment 3 incorporated combined phase and period shifts, which caused moderate disruption to timing and accuracy and revealed interactive effects of period and phase shifts on production. A 4th experiment included all feedback conditions in the same session to confirm differences across Experiments 1-3. These results are consistent with the view that actions and their perceptual consequences are coordinated in a way that distinguishes timing (phase shifts) from sequencing (period shifts). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simultaneous timing of multiple intervals: Implications of the scalar property.

Three experiments with pigeons are reported in which the scalar property in simultaneous timing tasks was studied. According to scalar expectancy theory, the scalar property should be maintained in simultaneous timing, but the behavioral theory of timing predicts that the scalar property should be evident only in independent timing. Experiment 1 showed that the appearance of distinct peaks at reinforcement times required about a 4:1 ratio between intervals. Experiment 2 (2-interval timing task) and Experiment 3 (3-interval timing task) used an individual trial analysis technique to examine high-rate responding segments bracketing the times of reinforcement. The standard deviations of the starting and stopping times of high-rate segments were linearly related to their means and to reinforcement time, supporting the scalar property in simultaneous timing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulating the interference effect in timing with varying stimulus onset asynchrony.

The interference effect on time judgments, when subjects are also required to perform a concurrent nontemporal task, is one of the most reliable findings in the time perception literature. In the present study, the interference between a time discrimination task (short or long tone) and a digit classification task (even or odd digit) was analysed using the overlapping tasks paradigm. Reaction times in the digit task were shorter at longer values of stimulus onset asynchrony (SOA) in Experiment 1, showing a clear modulation of interference with varying the relative position of the tasks. Using longer tone durations in Experiment 2, reaction times in the digit task were affected not only by the overlap between the tasks but also by the temporal proximity of responses in the timing and digit tasks. In Experiment 3, the effect of varying the SOA on performance on the digit task was abolished when the auditory tone was irrelevant, thus eliminating an interpretation in terms of distraction from the tone offset. We conclude that the interference effect in concurrent time discrimination and digit classification may be modulated by the degree of overlap between the tasks as well as by the overlap between late processing stages related to decision and response components in the 2 tasks. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Scalar expectancy theory and peak-interval timing in humans.

The properties of the internal clock, temporal memory, and decision processes used to time short durations were investigated. The peak-interval procedure was used to evaluate the timing of 8-, 12-, and 21-s intervals, and analyses were conducted on the mean response functions and on individual trials. A distractor task prevented counting, and visual feedback on accuracy and precision was provided after each trial. Mean response distributions were (a) centered at the appropriate real-time criteria, (b) highly symmetrical, and (c) scalar in their variability. Analysis of individual trials indicated more memory variability relative to response threshold variability. Taken together, these results demonstrate that humans show the same qualitative timing properties that other animals do, but with some quantitative differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociations in the timing of stationary and moving stimuli.

When participants are asked to localize the 1st position of a moving stimulus, they mislocalize it in the direction of the movement (Fr?hlich effect; F. W. Fr?hlich, 1923). This mislocalization points to a delay in the temporal sensation of a moving stimulus. However, the delay is in contrast to findings indicating a faster processing of moving stimuli. This potential dissociation was studied in 6 experiments. After establishing the effect spatially, different temporal tasks were examined under otherwise identical conditions. Simple as well as choice reaction times were shorter to moving than to stationary stimuli. Other tasks (choice reaction to structural features, temporal order judgement, and synchronization), however, produced opposite effects. Results support a view that the output of early stimulus processing directly feeds into the motor system, whereas the processing stages used, for example, for localization judgements are based on later integrative mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The dynamics of disruption from altered auditory feedback: Further evidence for a dissociation of sequencing and timing.

Three experiments were designed to test whether perception and action are coordinated in a way that distinguishes sequencing from timing (Pfordresher, 2003). Each experiment incorporated a trial design in which altered auditory feedback (AAF) was presented for varying lengths of time and then withdrawn. Experiments 1 and 2 included AAF that resulted in action-effect asynchronies (delayed auditory feedback) during simple tapping (Experiment 1) and melody production (Experiment 2). Asynchronous AAF immediately slowed production; this effect then diminished rapidly after removal of AAF. By contrast, sequential alterations of feedback pitch during melody production (Experiment 3) had an effect that varied over successive presentations of AAF (by increasing error rates) that lasted after its withdrawal. The presence of auditory feedback after withdrawal of asynchronous AAF (Experiments 1 and 2) led to overcompensation of timing, whereas the presence of auditory feedback did not influence performance after withdrawal of AAF in Experiment 3. Based on these results, we suggest that asynchronous AAF perturbs the phase of an internal timekeeper, whereas alterations to feedback pitch over time degrade the internal representation of sequence structure. (PsycINFO Database Record (c) 2011 APA, all rights reserved)