Physical and neural entrainment to rhythm: human sensorimotor coordination across tasks and effector systems.

The human sensorimotor system can be readily entrained to environmental rhythms, through multiple sensory modalities. In this review, we provide an overview of theories of timekeeping that make this neuroentrainment possible. First, we present recent evidence that contests the assumptions made in classic timekeeper models. The role of state estimation, sensory feedback and movement parameters on the organization of sensorimotor timing are discussed in the context of recent experiments that examined simultaneous timing and force control. This discussion is extended to the study of coordinated multi-effector movements and how they may be entrained

Identifying the information for the visual perception of relative phase

The production and perception of coordinated rhythmic movement are very specifically structured. For production and perception, 0° mean relative phase is stable, 180° is less stable, and no other state is stable without training. It has been hypothesized that perceptual stability characteristics underpin the movement stability characteristics, which has led to the development of a phase-driven oscillator model (e.g., Bingham, 2004a, 2004b). In the present study, a novel perturbation method was used to explore the identity of the perceptual information being used in rhythmic movement tasks. In the three conditions, relative position, relative speed, and frequency (variables motivated by the model) were selectively perturbed. Ten participants performed a judgment task to identify 0° or 180° under these perturbation conditions, and 8 participants who had been trained to visually discriminate 90° performed the task with perturbed 90° displays. Discrimination of 0° and 180° was unperturbed in 7 out of the 10 participants, but discrimination of 90° was completely disrupted by the position perturbation and was made noisy by the frequency perturbation. We concluded that (1) the information used by most observers to perceive relative phase at 0° and 180° was relative direction and (2) becoming an expert perceiver of 90° entails learning a new variable composed of position and speed

Transfer of learning between unimanual and bimanual rhythmic movement coordination: transfer is a function of the task dynamic.

Under certain conditions, learning can transfer from a trained task to an untrained version of that same task. However, it is as yet unclear what those certain conditions are or why learning transfers when it does. Coordinated rhythmic movement is a valuable model system for investigating transfer because we have a model of the underlying task dynamic that includes perceptual coupling between the limbs being coordinated. The model predicts that (1) coordinated rhythmic movements, both bimanual and unimanual, are organised with respect to relative motion information for relative phase in the coupling function, (2) unimanual is less stable than bimanual coordination because the coupling is unidirectional rather than bidirectional, and (3) learning a new coordination is primarily about learning to perceive and use the relevant information which, with equal perceptual improvement due to training, yields equal transfer of learning from bimanual to unimanual coordination and vice versa [but, given prediction (2), the resulting performance is also conditioned by the intrinsic stability of each task]. In the present study, two groups were trained to produce 90° either unimanually or bimanually, respectively, and tested in respect to learning (namely improved performance in the trained 90° coordination task and improved visual discrimination of 90°) and transfer of learning (to the other, untrained 90° coordination task). Both groups improved in the task condition in which they were trained and in their ability to visually discriminate 90°, and this learning transferred to the untrained condition. When scaled by the relative intrinsic stability of each task, transfer levels were found to be equal. The results are discussed in the context of the perception–action approach to learning and performance

Ecological mechanisms in cognitive science

© The Author(s) 2019. In 2010, Bechtel and Abrahamsen defined and described what it means to be a dynamic causal mechanistic explanatory model. They discussed the development of a mechanistic explanation of circadian rhythms as an exemplar of the process and challenged cognitive science to follow this example. This article takes on that challenge. A mechanistic model is one that accurately represents the real parts and operations of the mechanism being studied. These real components must be identified by an empirical programme that decomposes the system at the correct scale and localises the components in space and time. Psychological behaviour emerges from the nature of our real-time interaction with our environments—here we show that the correct scale to guide decomposition is picked out by the ecological perceptual information that enables that interaction. As proof of concept, we show that a simple model of coordinated rhythmic movement, grounded in information, is a genuine dynamical mechanistic explanation of many key coordination phenomena

The Influence of Dopamine Replacement on Movement Impairments During Bimanual Coordination in Parkinson’s Disease (PD)

The purpose of the current thesis was to investigate the influence of dopamine replacement on performance during bimanual coordination in individuals with Parkinson’s disease (PD) There has been conflicting research on the cause of movement impairments such as coordination deficits, slowed switching and upper limb freezing that occur during coordinated movements It is unclear whether decreased function of the dopaminergic system after withdrawal from dopamine replacement is responsible for these deficits Healthy age-matched control participants were compared to PD participants in two experiments to determine the movement impairments that occurred during three-dimensional wrist flexion-extension bimanual coordination as a result of PD. In addition, individuals with PD were compared without (‘off’) and with (‘on’) dopamine replacement in both experiments to determine whether modulation of the dopaminergic system influenced coordinated movements. In Experiment 1, continuous bimanual coordination was performed in m-phase (simultaneous wrist flexion and extension) and anti-phase (flexion of one wrist while extending other wrist) with movements externally paced with increasing across seven cycle frequencies (0.75 to 2 Hz). Visual feedback was also manipulated in one of three sensory conditions no vision, normal vision or augmented vision. Visual feedback, phase and cycle frequency manipulation was performed to determine whether other deficits (e.g. sensory and/or attentional deficits) may influence coordinated movements Despite reduced amplitude of movements in both limbs of individuals with PD (PD ‘off’), coordination deficits were not observed in PD compared to healthy control participants. In addition, there was an increased occurrence of upper limb freezing (ULF) when cycle frequency demand was greater Dopamine replacement did increase the amplitude of movements in individuals with PD but did not influence coordination performance or the occurrence of ULF. In Experiment 2, coordinated movements were initiated in either m-phase or antiphase and participants were required to voluntarily switch to the other phase pattern when an auditory cue was presented Trials were performed at one of two cycle frequencies (1 or 2 Hz) and one of two sensory conditions (no vision or normal vision) to determine whether other deficits (e.g. sensory and/or attentional deficits) may influence coordinated movement. In addition, a separate block of trials were performed in anti-phase coordination with an auditory cue that did not require a switch Non-switching trials were included to investigate whether the presence of a distracting cue could evoke ULF comparable to when switching between movements was required PD ‘off’ participants demonstrated slower switching, more delayed responses and deficits in coordination performance when compared to healthy control participants. The increased demand of cycle frequency particularly when initiating anti-phase coordination, after voluntary switching and with the presence of the auditory cue without switching contributed to a large occurrence of ULF in individuals with PD. Dopamine replacement improved the ability to switch between phase patterns but had no overall influence on coordination performance or the occurrence of ULF. Overall, the results of the current thesis demonstrated that dopamine replacement can improve motor symptoms during coordinated movements (e g hypometna and bradykinesia) but does not contribute to coordination performance or ULF in individuals with PD. As a consequence, it was concluded that coordination deficits and ULF are not caused by the dysfunctional dopaminergic system but rather associated to secondary impairment caused by PD. The movement impairments caused by secondary dysfunction of PD were proposed to be associated with increased attentional demands and possible executive dysfunction related to fronto-stnatal pathways that cannot be modulated by dopamine replacement. Thus, treatment of complex movement impairments such as coordination deficits and ULF may benefit from rehabilitation or non-dopamine therapies that focus on the global dysfunction caused by PD

Movement-related sensory feedback mediates the learning of a new bimanual relative phase pattern

On the basis of findings emphasizing the role of perceptual consequences in movement coordination, the authors tested the hypothesis that the learning of a new bimanual relative phase pattern would involve the matching of the movement-related sensory consequences (rather than the motor outflow commands) to the to-be-learned pattern. Two groups of participants (n = 10 in each) practiced rhythmically moving their forearms with a phase difference of 30°. In 1 group, a difference in the arms' eigenfrequencies was imposed such that synchronous generation of the left and right motor commands resulted in the required relative phase (30°), yielding incongruence between the motor commands and their sensory consequences. In the other group, the experimenter imposed no eigenfrequency difference so that the sensory consequences were congruent with the motor commands. Throughout the practice period, performance of both groups was assessed repeatedly for the congruent situation (i.e., no eigenfrequency difference). On those criterion tests, both groups performed the required pattern equally well. The authors discuss that result, which corroborated the hypothesis, from a dynamical systems perspective

CONTRIBUTION OF VELOCITY CONGRUENCY AND APPARENT STIFFNESS TO INTERFERENCE OF BIMANUAL RHYTHMIC-DISCRETE MOVEMENTS.

Many actions feature rhythmic and discrete movements, individually or in combinations. Rhythmic movements are defined as those having no clearly defined start and end-point, while discrete movements have a definite starting and ending posture. Performing a discrete movement against a base rhythm by the contralateral limb typically speeds up the rhythmic movement -- indicating the presence of bimanual coupling. While bimanual rhythmic/rhythmic interaction has been studied extensively in the field, understanding of the interaction between discrete and rhythmic movements has been less represented. In this thesis, I examined two potential sources of interlimb interference during rhythmic-discrete bimanual actions: 1) velocity congruence of the limbs, 2) co-contraction level of the synergist muscles. Hypothesis 1 predicted that the extent of rhythmic-discrete interference depends on the discrepancy between the velocities of the rhythmic and discrete movements, such that faster discrete movement would speed up the rhythmic movement and vice versa. Hypothesis 2 predicted that speeding up the rhythmic movement following the discrete response would be associated with increased muscle co-contraction in the rhythmic limb because higher apparent stiffness typically increases the natural frequency of oscillations. To address these hypotheses, I used a computational model of upper limb movements proposed by Ronsee et al. that allows simulation of both unimanual and bimanual rhythmic and discrete movements using the central pattern generator (CPG) concept. Discrete movement with an amplitude of 60 deg was simulated in two velocity conditions: Slow (peak velocity: 163 deg/s) and Fast (249 deg/s), these values differed by approximately 20% from the peak velocity of the rhythmic movement. Phase discrete movement initiation within rhythm was also manipulated. Dependent measures included rhythmic movement period, amplitude, phase, and level of co-contraction following the initiation of the discrete response were examined. The results showed that 1) the velocity of the discrete movement does not account for the changes of rhythmic behavior and (2) the level of co-contraction and the period shift of the rhythmic arm do not co-vary. However, the results suggested that the response of the rhythmic arm is dependent of the rhythmic movement\u27s phase during which the discrete movement is initiated

Constraints on coordination:Intrinsic dynamics, behavioral information and asymmetry in bimanual rhythmic coordination

Zonder oefening is het met pianospelen vrijwel onmogelijk om de handen onafhankelijk van elkaar te bewegen. De handbewegingen zijn op een bepaalde manier gekoppeld. Martine Verheul onderzocht hoe dat precies zit. Daarvoor liet ze haar proefpersonen met twee handen verschillende ritmes tikken. Naast persoonsgebonden verschillen blijken er ook taak-afhankelijke verschillen te zijn. Muzikale ervaring van de proefpersoon had een positief effect op de stabiliteit van tweehandige ritmische coördinatie. Daarna vergeleek Verheul links- en rechtshandigen bij het tikken van symmetrische en asymmetrische patronen. In tegenstelling tot taken waarbij de handen in verschillend tempo tikken blijkt bij het asymmetrisch tikken in een gelijk tempo de coördinatie even stabiel in beide handverdelingen. Verheul toont aan dat zowel de voorkeurshand als de niet-voorkeurshand de leidende rol op zich kan nemen. Die flexibiliteit vermindert echter bij het ouder worden. De coördinatieproblemen bij volwassenen met de ziekte van Parkinson komen niet voort uit de asymmetrische verdeling van symptomen over de twee lichaamshelften, maar zijn volgens Verheul het gevolg van centrale problemen met het koppelen van de ledematen.

相対的顕著性が複数肢協調運動に及ぼす影響

早大学位記番号:新7951早稲田大