Tapping Rate Research Articles

Statistical characteristics of finger-tapping data in Huntington’s disease

Measuring the rate of finger tapping is a technique commonly used as an indicator of impairment in degenerative neurological conditions, such as Huntington’s disease. The information it provides can be greatly enhanced by analysing not simply the overall tapping rate, but also the statistical characteristics of the individual times between each successive response. Recent technological improvements in the recording equipment allow the responses to be analysed extremely quickly, and permit modification of the task in the interest of greater clinical specificity. Here we illustrate its use with some pilot data from a group of manifest HD patients and age-matched controls. Even in this small cohort, differences in the responses are apparent that appear to relate to the severity of the disease as measured by conventional behavioural tests.

Paradoxical worsening of gait with levodopa in Parkinson disease

Despite many recent advances in the treatment of Parkinson disease (PD), levodopa is still the most effective medication for PD. While there are many “nondopaminergic” features of PD that do not improve with levodopa, PD motor symptoms generally improve with dopaminergic medications. However, not all the motor manifestations of PD are improved to the same extent and some may not respond at all to levodopa. Tremor is often less responsive to levodopa than bradykinesia. Different aspects of bradykinesia may even respond differently. For example, recent studies showed that with self-paced finger and hand movement tasks similar to those used in the Unified Parkinson's Disease Rating Scale, levodopa improved the speed of movement but had little effect on the amplitude of movement and on movement fatigue, although impairment of movement amplitude was more prevalent than impairment of speed in PD.1,2 In contrast, when finger tapping was paced to an external rhythm, patients with PD had a dramatic reduction in the amplitude of movement when the tapping rate was higher than 2 Hz and this reduction in amplitude did not improve with levodopa.3 Gait disturbance in …

The Effects of Stimulus Rate and Tapping Rate on Tapping Performance

when finger taps are synchronized with an isochronous click, it is known that tap-click asynchrony and its variability increase with the interonset interval (IOI). It remains unclear whether these results are due to the IOI or the intertap interval (ITI) duration. The present study examines how these two factors influence tapping performance by altering the tap-click ratio (i.e., 1:n tapping). It has been shown that holding the ITI constant while decreasing the IOI—so that extra clicks subdivide each tap—results in a reduction of tapping variability, described as a subdivision benefit (Repp, 2003). Two questions remain: Does asynchrony and variability increase with the ITI while holding the IOI constant? Does asynchrony decrease with the IOI while holding ITI constant? Using linear regression, both asynchrony and variability decreased with the IOI, with little additional effect of ITI. In contrast, when using ITI as a predictor, the contribution of IOI was significant, suggesting that IOI is the main determinant of tapping performance. In addition, an ANOVA revealed a disadvantage for 1:3 tapping, supporting a categorical distinction between duple and triple meters since 1:n tapping can engender the subjective feel of different metric structures.

Relationship between tapping intensity and tapping panel dryness susceptibility of some clones of Hevea brasiliensis in Southwestern Côte d’Ivoire

It is well known that the productivity and the susceptibility to the tapping panel dryness (TPD) of Hevea brasiliensis are determined by the intrinsic feature of each clone but also by the tapping system. Thus, in order to establish the tapping system that minimizes the TDP occurrence an experiment was carried out in Cote d'Ivoire with four high yielding clones including, PB 235, PB 255, IRCA 18 and IRCA 111. Five tapping systems (d2 6d/7 0/y, d3 6d/7 4/y, d4 6d/7 6/y, d5 6d/7 8/y, d6 6d/7 10/y) were applied to these clones, corresponding to a range of 100 % to 30 % of tapping intensities. The results show that the occurrence of TPD is closely related to the tapping intensity and the tapping system which consists in tapping twice per week with one day rest (S/2 d3 6d/7 4/y), was found to be the best tapping system. A quadratic relation was found between the rate of the TPD and the tapping intensity. Thus the clones IRCA 18 and IRCA 111, like PB 235 and PB 255, belong to the active metabolism clones. These clones also showed their adherence to the group of high rubber producer clones. This experiment also gave further evidence that the production of a tree for the tapping strongly depends on the intensity of tapping. It has also indicated that the intensity of tapping governed the tapping panel dryness rate among the clones having active metabolism, such as IRCA 18, IRCA 111, PB 235 and PB 255. (Resume d'auteur)

Timing and aging: Slowing of fastest regular tapping rate with preserved timing error detection and correction.

This study assessed motor limits of regular tapping, timing error detection, and correction in 60 participants aged from 19 to 98 years. Rate limitations on motor production were estimated from the average inter-tap interval when tapping as fast as possible for 30 s. Timing error detection required participants to judge whether a sound sequence presented at a slow, intermediate, or fast speed contained an irregularity because of phase shift. This was performed with or without synchronizing to the sounds. On the basis of the just-detectable positive phase shift (JND), participants synchronized with sequences containing phase shifts that were subliminal, just detectable or supraliminal. On average, JNDs were 9% of the inter-onset interval and by and large were not affected by synchronization tapping. Speed of error correction was estimated from the number of tones to return within 20% of the preshift synchronization error. Consistent with previous findings of motor slowing with aging, the fastest inter-tap interval increased with age. However, there was no age-related decline in JNDs or speed of error correction, both of which reflect predictive abilities for intervals within the motor repertoire of human adults. These results point towards intact timing error processing up to an advanced age. In assessing timing abilities in the brain of older adults, it is important to differentiate between motor slowing and its impact on rhythmic behavior (e.g., walking pace) from anticipatory mechanisms ('what to expect when') and how these are used to adjust the timing of actions ('what to do when').

F14 Speeded tapping assesses progression of huntington's disease within one year—results from the track-HD study

BackgroundSpeeded (ST) and metronome (MT) tapping have been shown to be sensitive in distinguishing premanifest (preHD) and manifest (HD) stages of Huntington's disease (HD) in the cross-sectional analysis of the...

Neural Substrates of Impaired Sensorimotor Timing in Adult Attention-Deficit/Hyperactivity Disorder

Timing abilities are critical to the successful management of everyday activities and personal safety, and timing abnormalities have been argued to be fundamental to impulsiveness, a core symptom of attention-deficit/hyperactivity disorder (ADHD). Despite substantial evidence of timing deficits in ADHD youth, only two studies have explicitly examined timing in ADHD adults and only at the suprasecond time scale. Also, the neural substrates of these deficits are largely unknown for both youth and adults with ADHD. The present study examined subsecond sensorimotor timing and its neural substrates in ADHD adults. Using functional magnetic resonance imaging, we examined paced and unpaced finger tapping in a sample of 20 unmedicated adults with ADHD and 19 control subjects comparable on age, sex, and estimated IQ. The blood oxygenation level-dependent contrast response was used to estimate task-related neural activity. Behavioral data showed no between-group differences in mean tapping rates but greater within-subject variability in tap-to-tap intervals for ADHD adults relative to control subjects. Importantly, ADHD adults had greater clock rather than motor variability, consistent with a central timing locus for the atypical movements. The imaging results demonstrated that, relative to control subjects, ADHD adults showed less activity in a number of regions associated with sensorimotor timing, including prefrontal and precentral gyri, basal ganglia, cerebellum, inferior parietal lobule, superior temporal gyri, and insula. Our findings show that subsecond timing abnormalities in ADHD youth persist into adulthood and suggest that abnormalities in the temporal structure of behavior observed in ADHD adults result from atypical function of corticocerebellar and corticostriatal timing systems.

Recruitment of Additional Brain Regions to Accomplish Simple Motor Tasks in Chronic Alcohol‐Dependent Patients

Chronic alcohol-dependent patients (ALC) exhibit neurocognitive impairments attributed to alcohol-induced fronto-cerebellar damage. Deficits are typically found in complex task performance, whereas simple tasks may not be significantly compromised, perhaps because of little understood compensatory changes. We compared finger tapping with either hand at externally paced (EP) or maximal self-paced (SP) rates and concomitant brain activation in ten pairs of right-hand dominant, age-, and gender-matched, severe, uncomplicated ALC and normal controls (NC) using functional magnetic resonance imaging (fMRI). Mean tapping rates were not significantly different in ALC and NC for either task, but SP tapping variances were greater in ALC for both hands. SP tapping was more rapid with dominant hand (DH) than non-dominant hand (NDH) for both groups. EP and SP tapping with the non-dominant hand demonstrated significantly more activation in ALC than NC in the pre and postcentral gyri, inferior frontal gyrus, inferior parietal lobule, and the middle temporal gyrus. Areas activated only by ALC (not at all by NC) during NDH tapping included the inferior frontal gyrus, middle temporal gyrus, and postcentral gyrus. There were no significant group activation differences with DH tapping. No brain regions activated more in NC than ALC. SP tapping in contrast to EP activated fronto-cerebellar networks in NC, including postcentral gyrus, anterior cingulate, and the anterior lobe and vermis of the cerebellum, but only parietal precuneus in ALC. These findings with NDH finger tapping support previous reports of neurocognitive inefficiencies in ALC. Inferior frontal activation with EP in ALC, but not in NC, suggests engagement of regions needed for planning, organization, and impulse regulation; greater contralateral parietal lobe activation with SP in ALC may reflect right hemispheric impairments in visuospatial performance. Contrasting brain activation during SP and EP suggests that ALC may not have enlisted a fronto-cerebellar network as did NC but rather employed a higher order planning mode by recruiting parietal lobe functions to attain normal mean finger tapping rates. Elucidation of the compensatory neural mechanisms that allow near normal performance by ALC on simple tasks can inform functional rehabilitation of patients in recovery.

The relationship between motor deficit and primary motor cortex hemispheric activation balance after stroke: longitudinal fMRI study

BackgroundIn the chronic stage of stroke, previous work has shown that the worse the hand motor deficit, the greater the shift of primary motor cortex (M1) activation towards the contralesional...

Time in motion: Effects of whole-body rotatory accelerations on timekeeping processes

The ability of effectively representing time ensures the efficiency and accuracy of sensory and motor processing. It is well documented that in still observers, subjective time varies in response to variations of external sensory inputs. However, it is still poorly understood how inertial inputs, which enable coding of body displacements in space, affect timekeeping processes in a dynamic agent. Here, we investigated the effects of rotatory body accelerations on the reproduction of an acoustic isochronous pacing rhythm. In a first experiment, healthy participants performed a finger tapping task in which responses were either synchronized to the rhythm (Synchronization), or performed in absence of the rhythm following its withdrawal (Continuation). Both tasks were performed in presence and absence of sinusoidal acceleratory rotations along the vertical head-body axis. We found that the representation of the target frequency varied continuously as a function of periodic variations of vestibular–proprioceptive information. However, the effects on Synchronization and Continuation were opposite in directionality: increases in velocity were associated to increases in Continuation tapping rate (indicating a subjective shortening of the target interval), and decreases in Synchronization tapping rate. This was due to different temporal delays with which body motion affected tapping rate generation in these two conditions. A second control experiment, which lacked a representational component of time, confirmed that body displacements in Experiment 1 had indeed affected an internal timekeeper, and not motor responses triggered by its operation. A third control experiment, procedurally identical to Experiment 1 with the exception of an increased displacement frequency, allowed us to establish that Continuation tapping rate varied anticipatorily with respect to body motion, while Synchronization tapping rate varied with a delay in response to body movements. The observed consistent directionality in timing error, can be considered an adaptive response of internal timing mechanisms to body movements in space, where greater rates of displacement prompt accelerated timed responses.

Finger Tapping Ability in Healthy Elderly and Young Adults

The maximum isometric force production capacity of the fingers decreases with age. However, little information is available on age-related changes in dynamic motor capacity of individual fingers. The purpose of this study was to compare the dynamic motor function of individual fingers between elderly and young adults using rapid single-finger and double-finger tapping. Fourteen elderly and 14 young adults performed maximum frequency tapping by the index, middle, ring, or little finger (single-finger tapping) and with alternate movements of the index-middle, middle-ring, or ring-little finger-pair (double-finger tapping). The maximum pinch force between the thumb and each finger, tactile sensitivity of each fingertip, and time taken to complete a pegboard test were also measured. Compared with young subjects, the older subjects had significantly slower tapping rates in all fingers and finger-pairs in the tapping tasks. The age-related decline was also observed in the tactile sensitivities of all fingers and in the pegboard test. However, there was no group difference in the pinch force of any finger. The tapping rate of each finger did not correlate with the pinch force or tactile sensitivity for the corresponding finger in the elderly subjects. Maximum rate of finger tapping was lower in the elderly adults compared with the young adults. The decline of finger tapping ability in elderly adults seems to be less affected by their maximum force production capacities of the fingers as well as tactile sensitivities at the tips of the fingers.

Quantitative Diffusion Tensor Imaging Tractography Metrics are Associated with Cognitive Performance Among HIV-Infected Patients

There have been many studies examining HIV-infection-related alterations of magnetic resonance imaging (MRI) diffusion metrics. However, examining scalar diffusion metrics ignores the orientation aspect of diffusion imaging, which can be captured with tractography. We examined five different tractography metrics obtained from global tractography maps (global tractography FA, average tube length, normalized number of streamtubes, normalized weighted streamtube length, and normalized total number of tubes generated) for differences between HIV positive and negative patients and the association between the metrics and clinical variables of disease severity. We also examined the relationship between these metrics and cognitive performance across a wide range of cognitive domains for the HIV positive and negative patient groups separately. The results demonstrated a significant difference between the groups for global tractography FA (t = 2.13, p = 0.04), but not for any of the other tractography metrics examined (p-value range = 0.39 to 0.95). There were also several significant associations between the tractography metrics and cognitive performance (i.e., tapping rates, switching 1 and 2, verbal interference, mazes; r > or = 0.42) for HIV infected patients. In particular, associations were noted between tractography metrics, speed of processing, fine motor control/speed, and executive function for the HIV-infected patients. These findings suggest that tractography metrics capture clinically relevant information regarding cognitive performance among HIV infected patients and suggests the importance of subtle white matter changes in examining cognitive performance.

Automaticity and attention in Huntington's disease: When two hands are not better than one

People with Huntington's disease (HD) commonly report difficulty carrying out two everyday tasks simultaneously. This difficulty, confirmed by experimental studies, is typically ascribed to impaired attention. Yet, dual-task problems extend to relatively simple tasks, such as walking and talking, which would ordinarily be considered relatively undemanding of attention. The study tests the hypothesis that in HD there is a deficit in the ability to automatise task performance. Thus, simple tasks, which place minimal demands on conscious attention in healthy controls, make disproportionately high demands on attentional resources in HD. We examined the performance of HD patients and healthy controls on a simple, paced finger-tapping task, comparing single-task (tapping with one hand) and dual-task (tapping with both hands simultaneously) performance. For HD patients, bimanual tapping increased the task demands: there was greater variability in tapping rate and patients reported that the 'dual-task' condition was more difficult. The opposite pattern was observed for controls. Variability in tapping performance in HD was highly correlated with performance on cognitive tasks that have the potential to be automatized but not with performance on tasks that are more demanding of executive control, suggesting a common substrate for cognitive and motor automaticity. The data support the hypothesis that HD patients are impaired in their capacity for automisation, and suggest that impaired automaticity may be one source of attentional deficits in HD. The findings have implications for the interpretation of 'high level' deficits in attention and executive function previously reported in HD.

Timing dysfunctions in schizophrenia as measured by a repetitive finger tapping task

Schizophrenia may be associated with a fundamental disturbance in the temporal coordination of information processing in the brain, leading to classic symptoms of schizophrenia such as thought disorder and disorganized and contextually inappropriate behavior. Although a variety of behavioral studies have provided strong evidence for perceptual timing deficits in schizophrenia, no study to date has directly examined overt temporal performance in schizophrenia using a task that differentially engages perceptual and motor-based timing processes. The present study aimed to isolate perceptual and motor-based temporal performance in individuals diagnosed with schizophrenia using a repetitive finger-tapping task that has previously been shown to differentially engage brain regions associated with perceptual and motor-related timing behavior. Thirty-two individuals with schizophrenia and 31 non-psychiatric control participants completed the repetitive finger-tapping task, which required participants to first tap in time with computer-generated tones separated by a fixed intertone interval (tone-paced tapping), after which the tones were discontinued and participants were required to continue tapping at the established pace (self-paced tapping). Participants with schizophrenia displayed significantly faster tapping rates for both tone- and self-paced portions of the task compared to the non-psychiatric group. Individuals diagnosed with schizophrenia also displayed greater tapping variability during both tone- and self-paced portions of the task. The application of a mathematical timing model further indicated that group differences were primarily attributable to increased timing – as opposed to task implementation – difficulties in the schizophrenia group, which is noteworthy given the broad range of impairments typically associated with the disorder. These findings support the contention that schizophrenia is associated with a broad range of timing difficulties, including those associated with time perception as well as time production.

Central and Peripheral Timing Variability in Children With Heavy Prenatal Alcohol Exposure

The study examined whether prenatal alcohol exposure is associated with increased motor timing variability when the timing response is partitioned into central clock variability, which indexes information processing at the central nervous system (CNS) level and motor delay variability, which reflects timing processes at the level of the peripheral nervous system. Eighteen children with histories of prenatal alcohol exposure and 22 control children were assigned to young (7 to 11 years) or older (12 to 17 years) groups. Children tapped a single response key with the index finger in synchrony with a series of externally generated tones (the paced phase). At the conclusion of these tones, children continued tapping (the continuation phase) while attempting to maintain the same rate of tapping imposed by the paced phase. Two blocks of tapping were completed with inter-tone-intervals set at either 400 or 900 milliseconds. Inter-response interval, central clock variability, and motor delay variability produced during the continuation phase were the dependent variables. Mean inter-response interval for the 4 groups did not differ for either time interval. Central clock variability produced by the young alcohol-exposed group was significantly greater than the two older groups for the 400 millisecond interval and all other groups for the 900 millisecond interval. Motor delay variability produced by the young alcohol-exposed group was significantly greater than the other three groups for both time intervals. Central and motor delay variability in children with and without alcohol exposure was directly related to the duration of the interval to be reproduced. Central and peripheral timing variability was significantly greater for the young alcohol-exposed children. This atypical timing may be related to the teratogenic effects of alcohol, although the negative effects are limited to younger alcohol-exposed children since there were no differences in central and peripheral timing variability between the older alcohol-exposed children and controls.

Functional changes of the cortical motor system in hereditary spastic paraparesis

Hereditary spastic paraparesis (HSP) is a heterogeneous group of disorders characterized by progressive bilateral lower limb spasticity. Functional imaging studies in patients with corticospinal tract involvement have shown reorganization of motor circuitry. Our study investigates functional changes in sensorimotor brain areas in patients with HSP. Twelve subjects with HSP and 12 healthy subjects were studied. Functional magnetic resonance imaging (fMRI) was used to measure brain activation during right-hand finger tapping. Image analysis was performed using general linear model and regions of interest (ROI)-based approach. Weighted laterality indices (wLI) and anterior/posterior indicies (wAI and wPI) were calculated for predefined ROIs. Comparing patients and controls at the same finger-tapping rate (1.8 Hz), there was increased fMRI activation in patients' bilateral posterior parietal cortex and left primary sensorimotor cortex. No differences were found when comparing patients and controls at 80% of their individual maximum tapping rates. wLI of the primary sensorimotor cortex was significantly lower in patients. Subjects with HSP also showed a relative increase in the activation of the posterior parietal and premotor areas compared with that of the primary sensorimotor cortex. Our findings demonstrate an altered pattern of cortical activation in subjects with HSP during motor task. The increased activation probably reflects reorganization of the cortical motor system.

Early, untreated Parkinson's disease patients show reaction time variability

While Parkinson's disease (PD) is associated with motor slowing, less attention has been paid to variability in performance on motor and cognitive tasks. To examine reaction time latencies and intraindividual variability in untreated patients with PD compared to healthy controls. Twenty-nine (19 men/10 women) patients with untreated PD and 16 controls (8 men/8 women) were examined using measures of simple reaction time (SRT) and choice reaction time (CRT) in addition to cognitive measures of executive function (Trail Making Test; adaptive digit ordering). Latencies and intraindividual variability were compared between groups. Partial correlation coefficients, adjusting for age, sex and education were used to examine the relationship between RT measures and motor or cognitive measures. Patients and controls did not differ with respect to age or sex distribution. Education and cognitive status differed between groups, but no subject was demented or clinically depressed. After adjusting for age, sex and education, significant group differences were found in latencies (2-choice RT and 8-choice RT) and intraindividual variability scores (all CRT conditions). Latencies did not differ significantly after adjusting for finger tapping rate. In the PD group neither the motor nor the executive measures correlated significantly with any of the reaction time measures. We conclude that CRT intraindividual variability and latencies are increased in untreated PD.

Vibrational Communication in Two Sympatric Species of Mantophasmatodea (Heelwalkers)

The communication via percussion of the abdomen on the substrate for species recognition and mate location of males and females of two sympatric species of the recently described insect order Mantophasmatodea (Heelwalkers) was investigated. Each sex produced a single and distinctive call. The female call consisted of repeated single pulses, whereas the more complex male call comprised repeated pulse trains. The calls of males and females of the two species were of similar general structure, but differed in most temporal characters such as pulse and pulse train repetition time. In behavioral playback experiments females reacted to the call of conspecific males by calling and decreasing locomotion. When stimulated with the call of the heterospecific, sympatric male, females showed no reaction. Males exhibited abdominal rubbing, high tapping rates, increased activity (both movement and active searching) as well as characteristic searching behavior at branch nodes, when presented with the conspecific female call. Being stimulated with the playback of the heterospecific female call and the conspecific male call respectively, males responded with less intense locomotor and searching behavior. The drumming behavior in the control situation (no playback) suggests that males sometimes call in the absence of other individuals.

Future Suicide Attempt and Responses to Serotonergic Challenge

Blunted neurohormonal responses to serotonergic agents are found in major depression and suicidal behavior, but there have been no prospective studies of their relationship to later suicide attempt. In this study, healthy volunteers and depressed subjects were administered a fenfluramine (FEN) and placebo challenge test at baseline and then followed for 2 years. Seven subjects made suicide attempts within the follow-up period. Healthy volunteers, depressed non-attempters, depressed past suicide attempters, and depressed future attempters were compared on plasma prolactin and cortisol responses, as well as on mood (Profile of Mood States; POMS) and behavioral measures that were assessed at baseline and at the end of each challenge testing day. Both past and future attempters had lower total prolactin output (area under the curve) in response to FEN relative to non-patients. Future attempters had lower cortisol response relative to all other groups. All subject groups reported a decrease in POMS Fatigue subscale score and increase in finger tapping rate after receiving FEN. Depressed subjects reported a significant decline in POMS Total, Depression, and Tension/Anxiety scores, but future attempters' did not, showing a slight mean increase. Lower cortisol response correlated with greater suicidal ideation 3 months and 1 year post-study. Logistic regression revealed that blunting of cortisol response and worsening of mood after FEN, and younger age could be used to predict later suicide attempt in the majority of cases (4/7). Results suggest that blunted cortisol and unfavorable acute mood response to serotonergic challenge, in the context of the general activating effects of these drugs, may be a risk factor for later suicide attempt.

Enhanced corticomotor excitability with dynamic fatiguing exercise of the lower limb in multiple sclerosis

To determine if task performance and fatigability during rapid repetitive exercise of the lower limb differ in a group of MS subjects compared to a control group, and what central changes accompany the development of fatigue and the period of recovery. Transcranial magnetic stimulation (TMS) was used to compare motor evoked potential (MEP) responses between 10 clinically definite MS subjects (7F, 33-64 years of age; EDSS <or= 4; MRC grade >or= 4/5) and 13 control subjects during and after 5 bouts of a 15-second maximum rate foot-tapping task performed at 1 minute intervals. Maximum voluntary contraction (MVC) force of ankle dorsiflexion was lower (15 %) in the MS group compared to controls; however there were no differences in the rate of foot tapping. The rate of foot tapping decreased during each bout of exercise to a comparable degree in both groups, but there was no overall deterioration in performance across the 5 repeat bouts in either group. MS subjects showed a greater decline in strength than controls after exercise (20.7+/-7.7% vs. 6+/-3.6%; p<0.05). MEP amplitude increased significantly for the exercised limb in both groups, but the increase was greater in MS subjects (65.9+/-27% vs. 31+/-19.6%; MS vs. control; p<0.05). MEP amplitude also increased for the non-exercised limb in controls (40.6+/-15.6%, p<0.01) but not in MS subjects. Mild to moderately affected MS subjects can perform a fatiguing exercise requiring a high level of central motor control but this is associated with a greater strength loss and increase in corticomotor excitability compared to unaffected individuals. Central adaptive processes are likely to have a significant role in maintaining task performance in MS.