Perfect Phase Correction in Synchronization With Slow Auditory Sequences

Phase correction during synchronization (finger tapping) with an isochronous auditory sequence is typically imperfect, requiring several taps to complete. However, two independent hypotheses predict that phase correction should approach perfection when the sequence tempo is slow. The present results confirm this prediction. The experiment used a phase perturbation method and a group of musically trained participants. As the sequence interonset interval increased from 300 to 1200 ms, the phase correction response to perturbations increased and approached instantaneous phase resetting between 700 and 1200 ms, depending on the individual. A possible explanation of this finding is that emergent timing of the periodic finger movement vanishes as the movement frequency decreases and thus ceases to compete with event-based timing.     

Phase Correction Following a Perturbation in Sensorimotor Synchronization Depends on Sensory Information

In models of sensorimotor synchronization, it is generally assumed that phase correction occurs in response to information about sensorimotor asynchrony or relative phase. Without such feedback, a phase perturbation in the motor activity should not be followed by phase correction. Alternatively, internally generated temporal expectations could provide a basis for phase correction in the absence of feedback. To test those hypotheses, the author conducted an experiment in which participants (N = 8) tapped their finger in synchrony with isochronous auditory sequences containing a single shifted event onset, after which there could be a gap of up to 3 missing events. Participants were instructed to not react to the shifted event and to continue tapping regularly during any gap. The shifted event caused an involuntary phase shift of the following tap. The shift was corrected if the sequence continued, but during a gap, the shift persisted without correction. Those results confirm that sensory feedback is necessary for phase correction to occur.     

Experience with Event Timing Does not Alter Emergent Timing: Further Evidence for Robustness of Event and Emergent Timing

Although, event and emergent timings are thought of as mutually exclusive, significant correlations between tapping and circle drawing (Baer, Thibodeau, Gralnick, Li, &; Penhune, 2013 Baer, L. H., Thibodeau, J. L. N., Gralnick, T. M., Li, K. Z. H., &; Penhune, V. B. (2013). The role of musical training in emergent and event-based timing. Frontiers in Human Neuroscience, 7(191), 1–10. doi:10.3389/fnhum.2013.00191.[Crossref], [PubMed] , [Google Scholar]; Studenka, Zelaznik, &; Balasubramaniam, 2012 Studenka, B. E., Zelaznik, H. N., &; Balasubramaniam, R. (2012). The distinction between tapping and circle drawing with and without tactile feedback: An examination of the sources of timing variance. The Quarterly Journal of Experimental Psychology, 65(6), 1086–1100. doi:10.1080/17470218.2011.640404.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]; Zelaznik &; Rosenbaum, 2010 Zelaznik, H. N., &; Rosenbaum, D. A. (2010). Timing processes are correlated when tasks share a salient event. Journal of Experimental Psychology: Human Perception and Performance, 36(6), 1565–1575. doi:10.1037/a0020380.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) suggest that emergent timing may not be as robust as once thought. We aimed to test this hypothesis in both a younger (18–25) and older (55–100) population. Participants performed one block of circle drawing as a baseline, then six blocks of tapping, followed by circle drawing. We examined the use of event timing. Our hypothesis that acute experience with event timing would bias an individual to use event timing during an emergent task was not supported. We, instead, support the robustness of event and emergent timing as independent timing modes.     

Measurements of Muscular Strength,Endurance, and Recovery Over Fifteen Successive Days

Muscular output was measured in terms of strength, endurance, impulse, and recovery, with 10 Ss, 4 times per day over 15 successive days. A general index (the mean percentage of baseline performance with all measures) indicated that performance generally improved over the first 5 or 6 days, and remained relatively stable thereafter. The measures of strength were sensitive to within-day effects, whereas endurance and recovery measures were not influenced by such circadian rhythms.     

Sequential and Biomechanical Factors Constrain Timing and Motion in Tapping

The authors examined how timing accuracy in tapping sequences is influenced by sequential effects of preceding finger movements and biomechanical interdependencies among fingers. Skilled pianists tapped sequences at 3 rates; in each sequence, a finger whose motion was more or less independent of other fingers' motion was preceded by a finger to which it was more or less coupled. Less independent fingers and those preceded by a more coupled finger showed large timing errors and change in motion because of the preceding finger's motion. Motion change correlated with shorter intertap intervals and increased with rate. Thus, timing of sequence elements is not independent of the motion trajectories that individuals use to produce them. Neither motion nor its relation to timing is invariant across rates.     

Rate Limits in Sensorimotor Synchronization With Auditory and Visual Sequences: The Synchronization Threshold and the Benefits and Costs of Interval Subdivision

Synchronization of finger taps with an isochronous event sequence becomes difficult when the event rate exceeds a certain limit. In Experiment 1, the synchronization threshold was reached at interonset intervals (IOIs) above 100 ms with auditory tone sequences (in a 1:4 tapping task) but at IOIs above 400 ms with visual flash sequences (1:1 tapping). Using IOIs above those limits, the author investigated in Experiment 2 the reduction in the variability of asynchronies that tends to occur when the intervals between target events are subdivided by additional identical events (1:1 vs 1:n tapping). The subdivision benefit was found to decrease with IOI duration and to turn into a cost at IOIs of 200–250 ms in auditory sequences and at IOIs of 450–500 ms in visual sequences. The auditory results are relevant to the limits of metrical subdivision and beat rate in music. The visual results demonstrate the remarkably weak rhythmicity of (nonmoving) visual stimuli.     

Continuous and Discontinuous Drawing: High Temporal Variability Exists Only in Discontinuous Circling in Young Children

The authors studied whether the drawing variability in young children is best explicable by (a) demands on the explicit timing system, (b) an underdeveloped ability to control limb dynamics, or (c) both. The explicit timing demands were lower in continuous drawing in comparison with the discontinuous task. The authors manipulated limb dynamics by changing the number of joints involved, with line drawing requiring fewer joints than circle drawing. Results showed that young children had high temporal variability in discontinuous circling but not in other conditions. The authors argue that both explicit timing and dynamic complexity of limb control may be determinants of temporal consistency and may thus play an important role in the development of drawing and writing skills in children.     

Bimanual Finger Tapping: Effects of Frequency and Auditory Information on Timing Consistency and Coordination

The authors' goal in this study was to probe the basis for an earlier, unexpected finding that preferred-frequency finger tapping tends to have higher frequencies and to be less stable for in-phase than for antiphase tasks. In follow-up experiments, 3 protocols were employed: a preferred-frequency replication in both coordination modes, a metronome-driven matching of the preferred frequencies to each of the coordination modes, and a frequency scaling of both modes. The original findings were affirmed for preferred frequency. Tapping to a metronome had a differential effect on in-phase and antiphase: A more stable coupling across frequencies was exhibited during in-phase. Under frequency scaling, the antiphase pattern decomposed at lower frequencies than did in-phase, but no phase transitions were observed. The loss of stable coordination in both modes was attended by sudden increases in frequency differences between fingers and by phase wandering. The emergence of those effects is discussed in light of asymmetric modifications to the Haken-Kelso-Bunz model (H. Haken, J. A. S. Kelso, & H. Bunz, 1985) and the task constraints of tapping.     

Early Menarche: A Review of Research on Trends in Timing, Racial Differences, Etiology and Psychosocial Consequences

This paper elucidates varying definitions of “early menarche” and reviews evidence in four well-documented areas: (a) A potential trend toward earlier maturation, (b) racial differences in menarcheal timing, (c) etiology of early puberty, and (d) consequences of early puberty. While teachers and physicians perceive menarche as occurring earlier than in the past, mean menarcheal age has remained relatively constant over the past 50 years. Conflicting results concerning racial differences in timing highlight the need for further research to unravel the effects of race and social economic status (SES). Evidence regarding the relative etiological contributions of nutrition, environmental stress, and genetics is evaluated. Maturing earlier than one’s peers has negative consequences for girls, especially when combined with simultaneous stressors. However, the negative psychosocial consequences of early puberty may not last into later adolescence or adulthood. Few studies have investigated early-maturing adolescents’ subjective experience with menarche, particularly those from non-white and non-middle-class backgrounds.This article is based on a paper presented at the 2003 Society for Menstrual Cycle Research Conference in Pittsburgh, PA.     

Timing, remembering, and discrimination

Four pigeons were first trained in a timing procedure. In one condition, each trial began with the presentation of an X on the center key, followed by a delay (short or long), after which two side keys were lit. If the delay was short, pecks to the red side key were reinforced. If the delay was long, pecks to the green side key were reinforced. In a second condition, the opposite contingencies applied following presentation of a square on the center key. Choice responses were then tested at 10 time intervals ranging from short to long (1 to 4 s and 4 to 7 s in different conditions). The two timing conditions were combined to create a remembering condition in which correct responding depended upon discrimination of both the sample stimulus (X or square) and the delay interval (short or long). Choices varied systematically across delay in timing conditions, but in remembering conditions, accurate choice at the training delays did not initially generalize to intermediate delays. However, with prolonged training in the remembering task, the response pattern began to resemble that of the timing conditions. Generalization gradients were asymmetrical, in accordance with Weber's Law, in that greater generalization occurred with longer delays than with shorter delays.     

Evidence of Common Timing Processes in the Control of Manual,Orofacial, and Speech Movements

Recent investigations of timing in motor control have been interpreted as support for the concept of brain modularity. According to this concept, the brain is organized into functional modules that contain mechanisms responsible for general processes. Keele and colleagues (Keele & Hawkins, 1982; Keele & Ivry, 1987; Keele, Ivry, & Pokorny, 1987; Keele, Pokorny, Corcos, & Ivry, 1985) demonstrated that the within-subject variability in cycle duration of repetitive movements is correlated across finger, forearm, and foot movements, providing evidence in support of a general timing module. The present study examines the notion of timing modularity of speech and nonspeech movements of the oral motor system as well as the manual motor system. Subjects produced repetitive movements with the finger, forearm, and jaw. In addition, a fourth task involved the repetition of a syllable. All tasks were to be produced with a 400-ms cycle duration; target duration was established with a pacing tone, which then was removed. For each task, the within-subject variability of the cycle duration was computed for the unpaced movements over 20 trials. Significant correlations were found between each pair of effectors and tasks. The present results provide evidence that common timing processes are involved not only in movements of the limbs, but also in speech and nonspeech movements of oral structures.     

Comparison of the Explicit Timing and Interspersal Interventions: Analysis of Problem Completion Rates,Student Preference,and Teacher Acceptability

Explicit timing and interspersal interventions were investigated using a within-subjects design with 45 third-grade students. A control assignment consisted of subtraction of a two digit number from a two digit number (i.e., target problem) and served as a baseline. An explicit timing assignment consisted of similar problems as those for the control assignment. The interspersal assignment consisted of similar problems as those for the control and explicit timing assignments with the addition of subtraction of a one digit number from a one digit number interspersed following every third target problem. Total problem completion rates, target problem completion rates, accuracy on target problems and students' rating regarding difficulty, time, effort, and preference between assignments for class work were collected. Student preference choices were analyzed for fit with the discrete task completion hypothesis. Three trials were administered. Results indicated that: (a) students completed more total problems during interspersal, (b) target problem completion rates were higher during explicit timing, (c) accuracy rates remained constant, (d) students rated the explicit timing assignment as requiring more time and being more difficult for all trials and as requiring more effort for trial 2 and 3, (e) students selected the interspersal assignment to do in class as compared to the explicit timing assignment for all trials, and (f) the data fit the discrete task completion hypothesis relatively well for all trials. Discussion focuses on comparing academic interventions based on problem completion rates, student preference, and acceptability data.     

Modulation of Response Timing in ADHD,Effects of Reinforcement Valence and Magnitude

The present study investigated the impact of reinforcement valence and magnitude on response timing in children with ADHD. Children were required to estimate a 1-s interval, and both the median response time (response tendency) and the intrasubject-variability (response stability) were investigated. In addition, heart rate and skin conductance were measured to examine the autonomic responses to reinforcement. Feedback-only trials were compared to low response cost trials (response cost for incorrect responses), low reward trials (reward for correct responses), high response cost and high reward trials. In feedback-only trials, children with ADHD underestimated more severely the interval and responded more variably than controls. Children with ADHD, unlike controls, were unaffected by the reinforcement conditions in terms of time underestimations. The variability of responding, on the other hand, decreased under conditions of reinforcement to a larger extent in children with ADHD than controls. There were no indications that children with ADHD were abnormally affected by the valence or magnitude of reinforcement. Furthermore, skin conductance responses increased when feedback was coupled with reinforcement, an effect which was larger in children with ADHD than controls. This could be interpreted as demonstrating that children with ADHD suffer from a diminished awareness of the significance of feedback in the feedback-only condition. The current study suggests that children with ADHD suffer from motivation problems when reinforcement was not available, at least when variability in responding was measured. Underestimations of time may reflect more stable deficits in ADHD.     

Temporal Precision in Tapping and Circle Drawing Movements at Preferred Rates is Not Correlated: Further Evidence Against Timing as a General-Purpose Ability

Recently, researchers have discovered that individuals who are consistent timers in a tapping task are not necessarily consistent timers when they perform a continuous drawing task. In other words, nonsignificant correlations were found among tapping and drawing movements for timing precision (S. D. Robertson et al., 1999). In the present experiment, the authors investigated whether or not consistency in timing for tapping and drawing was correlated when participants (N = 24) were allowed to move at their preferred rate of movement. There were no significant correlations between tapping and drawing in terms of timing precision. That result lends further support to the notion that timing behavior is specific to the nature of the task, and thus further weakens the idea that timing is a generalized ability that can be imposed on a variety of different types of tasks.     

时间知觉的脑机制:时钟模型的困境和新导向

长期以来人们认为神经系统是通过类似于时钟的方式来实现对一段时间的知觉的,并认为多巴胺能系统(基地神经节)和时钟的快慢有关。与多巴胺信号有关的药物的动物实验的结果以及帕金森氏症(parkinson’s disease)患者的行为表现被看作是支持以上看法的证据。然而,最近的大量研究对这个理论提出了挑战,结合行为研究和脑机制研究的新成果,研究者提出了知觉信息可以通过神经活动状态或加工中的能量消耗来表达。     

The Timing of Conscious Experience: A Critical Review and Reinterpretation of Libet''s Research

An extended examination of Libet's works led to a comprehensive reinterpretation of his results. According to this reinterpretation, the Minimum Train Duration of electrical brain stimulation should be considered as the time needed to create a brain stimulus efficient for producing conscious sensation and not as a basis for inferring the latency for conscious sensation of peripheral origin. Latency for conscious sensation with brain stimulation may occurafterthe Minimum Train Duration. Backward masking with cortical stimuli suggests a 125–300 ms minimum value for the latency for conscious sensation of threshold skin stimuli. Backward enhancement is not suitable for inferring this latency. For determining temporal relations between stimuli that correspond to subjects' reports, theendof cerebral Minimum Train Duration should be used as reference, rather than its onset. Results of coupling peripheral and cortical stimuli are explained by a latency after the cortical Minimum Train Duration, having roughly the same duration as the latency for supraliminal skin stimuli. Results of coupling peripheral stimuli and stimuli to medial lemniscus (LM) are explained by a shorter LM latency and/or a longer peripheral latency. This interpretation suggests a 230 ms minimum value for the latency for conscious sensation of somatosensory near-threshold stimuli. The backward referral hypothesis, as formulated by Libet, should not be retained. Long readiness potentials preceding spontaneous conscious or nonconscious movements suggest that both kinds of movement are nonconsciously initiated. The validity of Libet's measures of W and M moments (Libet et al., 1983a) is questionable due to problems involving latencies, training, and introspective distinction of W and M. Veto of intended actions may be initially nonconscious but dependent on conscious awareness.     

Student Preference for Explicit Timing and Interspersal Procedures as a Function of Math Problem Completion Rates: Testing the Discrete Task Completion Hypothesis

A within-subjects design was used to compare explicit timing and interspersal with college students. Students were given 3 minutes to complete problems on the explicit timing assignment (25 problems, 3 digits –3 digits) and the interspersal assignment (25 similar problems and 10 problems, 1 digit –1 digit). Results indicated that: (a) students completed more total problems during interspersal for both trials, (b) students completed more target problems during explicit timing for the second trial, and (c) students only preferred interspersal for the first trial. The data from trial one fit the discrete task completion hypothesis and matching law, yet the data from trial two do not match as closely (Skinner, 2002). Discussion focuses on continued need for more research on academic interventions, comparing academic interventions, the discrete task completion hypothesis, and the matching law.     

Wittgenstein on the duration and timing of mental phenomena: episodes,understanding and rule-following

ABSTRACT

Wittgenstein’s later works are full of questions about the timing and duration of mental phenomena. These questions are often awkward ones, and Wittgenstein seems to take their awkwardness to be philosophically revealing, but if we ask what it is that these questions reveal then different interpretations are possible. This paper suggests that there are at least six different ways in which the timing of mental phenomena can be awkward. By identifying these we can give sense to some of Wittgenstein’s more cryptic remarks, and doing this enables us to clarify some obscure elements in his picture of the mind, including the distinction between sensations and feelings, and his account of the rational status of those processes out of which rule-following is built.     

Perinatal depression influences on infant negative affectivity: Timing,severity, and co-morbid anxiety

Accumulating evidence suggests that antenatal depression predicts infants’ negative affectivity, albeit with variable effect sizes. With a prospective longitudinal design, we sought to explain that variability by addressing questions about timing of the depression across pregnancy and the early postpartum, the role of high symptom levels relative to diagnosed depression, comorbidity with anxiety, and the potential mediating role of neuroendocrine functioning. Primiparous women (n = 77) with histories of depression prior to pregnancy were assessed for cortisol levels monthly beginning by mid-pregnancy. Depression symptom levels and diagnostic status were similarly assessed monthly in pregnancy and also until infants reached three months of age, when mothers completed the Infant Behavior Questionnaire-Revised to measure infant negative affectivity. Antenatal depression symptoms and infant negative affectivity were positively associated (r = .39). Controlling for depression symptom levels in other trimesters, only second trimester depression symptoms predicted higher infant negative affectivity (β = .44). With postpartum depression symptom levels in the model, only antenatal depression symptoms predicted infant negative affectivity (β = .45). In the context of depression, neither antenatal anxiety symptoms nor anxiety disorder diagnosis were associated with infant NA scores. The hypothesized role of elevated maternal cortisol as a mechanism for the association between antenatal depression and infant NA was not supported. Our findings contribute to efforts to more precisely identify infants of perinatally depressed mothers who are at greater risk for elevated negative affectivity, suggesting a window of vulnerability in mid pregnancy and the need for further study of potential mechanisms.