Implicit contributions to dual visuomotor adaptation.

The ability to seamlessly switch between different visuomotor mappings is critical for effective interactions in a dynamic environment. This experiment aimed to establish the contributions of implicit (unconscious) processes to the concurrent adaptation of one's reaches to two opposing, randomly switching, novel visuomotor mappings (i.e.

The effects of mental fatigue on explicit and implicit contributions to visuomotor adaptation.

The goal of the current research was to establish the impact of mental fatigue on the contributions of explicit (i.e., conscious strategy) and implicit (unconscious) processes to visuomotor adaptation.

The Influence of Age on the Intermanual Transfer and Retention of Implicit Visuomotor Adaptation.

We examined age-related changes in intermanual transfer and retention of implicit visuomotor adaptation. We further asked if providing augmented somatosensory feedback regarding movement endpoint would enhance visuomotor adaptation. Twenty young adults and twenty older adults were recruited and randomly divided into an Augmented Feedback group and a Control group.

Assessing proprioceptive acuity in people with multiple sclerosis.

Background: Proprioceptive acuity and impairments in proprioceptively guided reaches have not been comprehensively examined in people with multiple sclerosis (MS).

Objective: To examine proprioceptive acuity in people with MS who self-report and who do not self-report upper limb (UL) impairment, and to determine how people with MS reach proprioceptive targets.

Methods: Twenty-four participants with MS were recruited into two groups based on self-reported UL impairment: MS-R (i.

Response preparation of a secondary reaction time task is influenced by movement phase within a continuous visuomotor tracking task.

The simultaneous performance of two motor tasks is challenging. Currently, it is unclear how response preparation of a secondary task is impacted by the performance of a continuous primary task. The purpose of the present experiment was to investigate whether the position of the limb performing the primary cyclical tracking task impacts response preparation of a secondary reaction time task.

Improved proprioception does not benefit visuomotor adaptation.

Visuomotor adaptation arises when reaching in an altered visual environment, where one's seen hand position does not match their felt (i.e., proprioceptive) hand position in space.

The Role of Awareness on Motor-Sensory Temporal Recalibration.

Temporal recalibration (TR) may arise to realign asynchronous stimuli after exposure to a short, constant delay between voluntary movement and sensory stimulus. The objective of this study was to determine if awareness of the temporal lag between a motor response (i.e.

The influence of awareness on implicit visuomotor adaptation.

It is well documented that reaches are adapted when reaching with a visuomotor distortion (i.e., rotated cursor feedback).

Assessing visually guided reaching in people with multiple sclerosis with and without self-reported upper limb impairment.

The ability to accurately complete goal-directed actions, such as reaching for a glass of water, requires coordination between sensory, cognitive and motor systems. When these systems are impaired, like in people with multiple sclerosis (PwMS), deficits in movement arise. To date, the characterization of upper limb performance in PwMS has typically been limited to results attained from self-reported questionnaires or clinical tools.

Changes in Movement Control Processes Following Visuomotor Adaptation.

Goal-directed reaches are modified based on previous errors experienced (i.e., offline control) and current errors experienced during movement execution (i.

Age-related changes in upper limb coordination in a complex reaching task.

When reaching to targets within arm's reach, intentional trunk motion must be neutralized by compensatory motion of the upper limb (UL). Advanced age has been associated with deterioration in the coordination of multi-joint UL movements. In the current study, we looked to determine if older adults also have difficulties modifying their UL movements (i.

Proprioceptive recalibration following implicit visuomotor adaptation is preserved in Parkinson's disease.

Individuals with Parkinson's disease (PD) and healthy adults demonstrate similar levels of visuomotor adaptation provided that the distortion is small or introduced gradually, and hence, implicit processes are engaged. Recently, implicit processes underlying visuomotor adaptation in healthy individuals have been proposed to include proprioceptive recalibration (i.e.

Intermanual transfer and retention of visuomotor adaptation to a large visuomotor distortion are driven by explicit processes.

Reaching with a visuomotor distortion in a virtual environment leads to reach adaptation in the trained hand, and in the untrained hand. In the current study we asked if reach adaptation in the untrained (right) hand is due to transfer of explicit adaptation (EA; strategic changes in reaches) and/or implicit adaptation (IA; unconscious changes in reaches) from the trained (left) hand, and if this transfer changes depending on instructions provided. We further asked if EA and IA are retained in both the trained and untrained hands.

Central fatigue mechanisms are responsible for decreases in hand proprioceptive acuity following shoulder muscle fatigue.

Muscle fatigue is a complex phenomenon, consisting of central and peripheral mechanisms which contribute to local and systemic changes in motor performance. In particular, it has been demonstrated that afferent processing in the fatigued muscle (e.g.

Visual processing is diminished during movement execution.

Recent research has suggested that visual discrimination and detection may be enhanced during movement preparation and execution, respectively. The current study examined if visual perceptual processing is augmented prior to or during a movement through the use of an Inspection Time (IT) task. The IT task involved briefly presenting (e.

Going offline: differences in the contributions of movement control processes when reaching in a typical versus novel environment.

Human movements are remarkably adaptive. We are capable of completing movements in a novel visuomotor environment with similar accuracy to those performed in a typical environment. In the current study, we examined if the control processes underlying movements under typical conditions were different from those underlying novel visuomotor conditions.

Experiencing the Cross-Sensory Error Signal During Movement Leads to Proprioceptive Recalibration.

Reaching to targets in a virtual reality environment with misaligned visual feedback of the hand results in changes in movements (visuomotor adaptation) and sense of felt hand position (proprioceptive recalibration). We asked if proprioceptive recalibration arises even when the misalignment between visual and proprioceptive estimates of hand position is only experienced during movement. Participants performed a "shooting task" through the targets with a cursor that was rotated 30° clockwise relative to hand motion.

Age differences in arm-trunk coordination during trunk-assisted reaching.

Reaching for an object is a basic motor skill that requires precise coordination between elbow, shoulder and trunk motion. The purpose of this research study was to examine age-related differences in compensatory arm-trunk coordination during trunk-assisted reaching. To engage the arm and trunk, an older and younger group of participants were asked to (1) maintain a fixed hand position while flexing forward at the trunk [stationary hand task (SHT)] and (2) reach to a within-arm's reach target while simultaneously flexing forward at the trunk [reaching hand task (RHT)] (Raptis et al.

Movement imagery as a predictor of online control in typically developing children.

The ability to mentally represent actions is suggested to play a role in the online control of movement in healthy adults. Children's movement imagery ability and online control have been shown to develop at similar nonlinear rates. The current study investigated the relationship between movement imagery and online control in children by comparing implicit and explicit movement imagery measures with the ability to make online trajectory corrections.

The influence of awareness on explicit and implicit contributions to visuomotor adaptation over time.

Explicit (strategic) and implicit (unconscious) processes play a role in visuomotor adaptation (Bond and Taylor, J Neurophysiol 113:3836-3849, https://doi.org/10.1152/jn.

Long-term retention of proprioceptive recalibration.

Sensorimotor changes are well documented following reaches with altered visual feedback of the hand. Specifically, reaches are adapted and proprioceptive estimates of felt hand position shifted in the direction of the visual feedback experienced. While research has examined one's ability to retain reach adaptation, limited attention has been given to the retention of proprioceptive recalibration.

Adaptation to proprioceptive targets following visuomotor adaptation.

In the following study, we asked if reaches to proprioceptive targets are updated following reach training with a gradually introduced visuomotor perturbation. Subjects trained to reach with distorted hand-cursor feedback, such that they saw a cursor that was rotated or translated relative to their actual hand movement. Following reach training trials with the cursor, subjects reached to Visual (V), Proprioceptive (P) and Visual + Proprioceptive (VP) targets with no visual feedback of their hand.

Offline continuous theta burst stimulation over right inferior frontal gyrus and pre-supplementary motor area impairs inhibition during a go/no-go task.

In a typical go/no-go task a single imperative stimulus is presented each trial, either a go or no-go stimulus. Participants are instructed to initiate a known response upon appearance of the go-signal and withhold the response if the no-go signal is presented. It is unclear whether the go-response is prepared in advance of the imperative stimulus in a go/no-go task.

Go-activation endures following the presentation of a stop-signal: evidence from startle.

Unlabelled: It has been proposed that, in a stop-signal task (SST), independent go- and stop-processes "race" to control behavior. If the go-process wins, an overt response is produced, whereas, if the stop-process wins, the response is withheld. One prediction that follows from this proposal is that, if the activation associated with one process is enhanced, it is more likely to win the race.

Time Course of Reach Adaptation and Proprioceptive Recalibration during Visuomotor Learning.

Training to reach with rotated visual feedback results in adaptation of hand movements, which persist when the perturbation is removed (reach aftereffects). Training also leads to changes in felt hand position, which we refer to as proprioceptive recalibration. The rate at which motor and proprioceptive changes develop throughout training is unknown.