Movement Initiation Research Articles

Exploring EEG spectral and temporal dynamics underlying a hand grasp movement.

For brain-computer interfaces, resolving the differences between pre-movement and movement requires decoding neural ensemble activity in the motor cortex's functional regions and behavioural patterns. Here, we explored the underlying neural activity and mechanisms concerning a grasped motor task by recording electroencephalography (EEG) signals during the execution of hand movements in healthy subjects. The grasped movement included different tasks; reaching the target, grasping the target, lifting the object upwards, and moving the object in the left or right directions. 163 trials of EEG data were acquired from 30 healthy participants who performed the grasped movement tasks. Rhythmic EEG activity was analysed during the premovement (alert task) condition and compared against grasped movement tasks while the arm was moved towards the left or right directions. The short positive to negative deflection that initiated around -0.5ms as a wave before the onset of movement cue can be used as a potential biomarker to differentiate movement initiation and movement. A rebound increment of 14% of beta oscillations and 26% gamma oscillations in the central regions was observed and could be used to distinguish pre-movement and grasped movement tasks. Comparing movement initiation to grasp showed a decrease of 10% in beta oscillations and 13% in gamma oscillations, and there was a rebound increment 4% beta and 3% gamma from grasp to grasped movement. We also investigated the combination MRCPs and spectral estimates of α, β, and γ oscillations as features for machine learning classifiers that could categorize movement conditions. Support vector machines with 3rd order polynomial kernel yielded 70% accuracy. Pruning the ranked features to 5 leaf nodes reduced the error rate by 16%. For decoding grasped movement and in the context of BCI applications, this study identifies potential biomarkers, including the spatio-temporal characteristics of MRCPs, spectral information, and choice of classifiers for optimally distinguishing initiation and grasped movement.

THE INFLUENCE OF THE INDONESIAN NATIONAL MOVEMENT IN THE EARLY ISLAMIC MOVEMENT IN MALAYSIA

This article raises the main question: How was the influence of the Indonesian nationalist movement namely nationalism and Islam in the initial nationalism movement in Malaysia? Using the political history approach of this article reveals this important issue. First, the Indonesian nationalism movement had influenced the nationalist movement in Malaysia through Indonesian political activists to Malaysia, then known as Malaysia. The important results of this article make an important contribution that not only is there a national political connection to the formation of Malaysian independence, but the spirit of nationalism and Islam is united in the influence of the early Islamic nationalist movement in Malaysia.Keywords: Indonesian nationalism movement, nationalism movement in Malaysia, islamic movement, islamic political party

Presenting Patterns of Genetically Determined Developmental Encephalopathies With Epilepsy and Movement Disorders: A Single Tertiary Center Retrospective Cohort Study.

BackgroundThis paper aimed to evaluate the frequency of observation of genetically determined developmental encephalopathies with epilepsy and movement disorders in a specialistic center, the distribution of etiologies and presenting clinical hallmarks, and the mean times for the achievement of molecular genetic diagnosis.Patients and MethodsRetrospective data about clinical phenotypes, etiology, and diagnostic pathways were collected in all the genetically confirmed patients with developmental encephalopathies with epilepsy and movement disorders referred to our institution between 2010 and 2020. The cohort was divided into two groups according to the predominant movement disorder type: 1) Group A: patients with hyperkinetic movement disorders; 2) Group B: patients with hypokinetic movement disorders. Both groups were analyzed in terms of developmental, epileptic, and movement disorder phenotypes.ResultsThe cohort included 69 patients (Group A = 53; Group B = 16). The etiological spectrum was heterogeneous with a predominance of Rett and Angelman syndrome in Group A and neurodegenerative disorders in Group B. A moderate/severe intellectual disability was assessed in 58/69 patients (mean age at the first signs of developmental impairment = 1,87 ± 1,72 years). Group A included patients with an earlier onset of epileptic seizures (2,63 ± 3,15 vs. 4,45 ± 5,55 years of group B) and a predominant generalized motor semiology of seizures at the onset. Focal seizures were the main initial epileptic manifestations in Group B. Seizures were noticed earlier than movement disorders in Group A while the opposite occurred in Group B. A higher increase in molecular genetic diagnosis was obtained in the last five years. Mean diagnostic delay was longer in Group B than in Group A (12,26 ± 13,32 vs. 5.66 ± 6.41 years). Chorea as an initial movement disorder was associated with a significantly longer diagnostic delay and a higher age at etiological diagnosis.ConclusionsThis study suggested: (a) a higher frequency of genetic defects involving neurotransmission, neuronal excitability, or neural development in patients with hyperkinetic movement disorders; (b) a higher frequency of neurodegenerative courses and a longer diagnostic delay in patients with hypokinetic movement disorders.

Brain Dynamics Underlying Preserved Cycling Ability in Patients With Parkinson's Disease and Freezing of Gait.

Parkinson’s disease (PD) is generally associated with abnormally increased beta band oscillations in the cortico-basal ganglia loop during walking. PD patients with freezing of gait (FOG) exhibit a more distinct, prolonged narrow band of beta oscillations that are locked to the initiation of movement at ∼18 Hz. Upon initiation of cycling movements, this oscillation has been reported to be weaker and rather brief in duration. Due to the suppression of the overall beta band power during cycling and its continuous nature of the movement, cycling is considered to be less demanding for cortical networks compared to walking, including reduced need for sensorimotor processing, and thus unimpaired continuous cycling motion. Furthermore, cycling has been considered one of the most efficient non-pharmacological therapies with an influence on the subthalamic nucleus (STN) beta rhythms implicative of the deep brain stimulation effects. In the current review, we provide an overview of the currently available studies and discuss the underlying mechanism of preserved cycling ability in relation to the FOG in PD patients. The mechanisms are presented in detail using a graphical scheme comparing cortical oscillations during walking and cycling in PD.

Potency matters: Impacts of embryonic exposure to nAChR agonists thiamethoxam and nicotine on hatching success, growth, and neurobehavior in larval zebrafish

ABSTRACT Thiamethoxam (TM) is a neonicotinoid insecticide that acts as a nicotinic acetylcholine receptor (nAChR) agonist. While designed to specifically target invertebrate nAChRs, recent studies have reported adverse effects of neonicotinoid exposure in early life-stage fish. This study examined the health and neurobehavioral impacts of chronic exposure to various concentrations of TM or nicotine (NIC) in early life zebrafish (Danio rerio) in conjunction with in-silico molecular docking to compare their ligand–receptor interactions with vertebrate nAChR. Chronic exposure to both reduced survival by approximately 20% (163 µg TM/l) and 25–100% (≥0.49 µg NIC/l). Hatching and growth were impaired following exposure to ≥0.21 µg TM/l or 4.9 µg NIC/l. Both TM and NIC produced morphological and behavioral indicators of neurotoxicity, with more potent effects following NIC exposure. NIC impaired embryonic motor activity by 40% (49 µg NIC/l), while both TM and NIC significantly altered predator escape response in larvae, specifically the latency and the initial burst movement of the response were impacted. Molecular docking predicted variations in the type and strength of interactions that occur between NIC or TM and vertebrate nAChR. These findings demonstrate that chronic exposure to TM might impact general health and neurobehavior of early-stage zebrafish. Our data support hypotheses that TM presents low affinity for vertebrate nAChR but may still pose an adverse risk to larval fish growth and neurobehavior.

Check or Go? Impact of Doubt on the Hierarchical Organization of the Mediofrontal Area

BackgroundBased on numerous imaging and electrophysiological studies, the presupplementary motor area (pre-SMA) and the rostral cingulate motor area are cortical regions considered to be essential to voluntary movement initiation and behavioral control. However, their respective roles and functional interactions remain a long-standing and still debated question. MethodsHere, we trained 2 rhesus monkeys (Macaca mulatta) in a complex cognitive task to compare the neuronal activity of these 2 regions on the medial wall during both perceptual and internally guided decisions. ResultsWe confirmed the implication of both areas throughout the decision process. Critically, we demonstrate that instead of a stable invariant role, the pre-SMA and rostral cingulate motor area manifested a versatile hierarchical relationship depending on the mode of movement initiation. Whereas pre-SMA neurons were primarily engaged in decisions based on perceptual information, rostral cingulate motor area neurons preempted the decision process in case of an internally doubt-driven checking behavior, withholding pre-SMA recruitment during the time spent inhibiting the habitual action. ConclusionsWe identified a versatile hierarchical organization of the mediofrontal area that may substantially affect normal and pathological decision processes because adaptive behaviors, such as doubt-checking and its compulsive counterpart, rely on this subtle equilibrium in controlling action initiation.

Reaching and Grasping Movements in Parkinson's Disease: A Review.

Parkinson’s disease (PD) is known to affect the brain motor circuits involving the basal ganglia (BG) and to induce, among other signs, general slowness and paucity of movements. In upper limb movements, PD patients show a systematic prolongation of movement duration while maintaining a sufficient level of endpoint accuracy. PD appears to cause impairments not only in movement execution, but also in movement initiation and planning, as revealed by abnormal preparatory activity of motor-related brain areas. Grasping movement is affected as well, particularly in the coordination of the hand aperture with the transport phase. In the last fifty years, numerous behavioral studies attempted to clarify the mechanisms underlying these anomalies, speculating on the plausible role that the BG-thalamo-cortical circuitry may play in normal and pathological motor control. Still, many questions remain open, especially concerning the management of the speed-accuracy tradeoff and the online feedback control. In this review, we summarize the literature results on reaching and grasping in parkinsonian patients. We analyze the relevant hypotheses on the origins of dysfunction, by focusing on the motor control aspects involved in the different movement phases and the corresponding role played by the BG. We conclude with an insight into the innovative stimulation techniques and computational models recently proposed, which might be helpful in further clarifying the mechanisms through which PD affects reaching and grasping movements.

The Effect of Swallowing Cues in Healthy Individuals: An Exploratory Study.

The goal of this study was to determine whether providing verbal and visual cues about swallowing changes the timing of swallowing events, and whether this information interacts with bolus volume. 20 healthy adults swallowed 5ml and 15ml liquid barium mixed with orange juice under videofluoroscopy during 2 conditions: one condition absent swallowing-specific cues and one condition with verbal and visual input about the swallowing process. Outcome measures included the timing of 10 swallowing events and the number of swallows per bolus. As expected, volume had a significant effect on all outcome measures (p < 0.05). Three timing events differed by cueing condition: 1. swallowing reaction time was earlier for control (- 9.45ms vs. - 2.01ms, p = 0.033); 2. the time between initial hyoid movement and maximum hyoid elevation was longer for control (152.85ms vs. 143.79ms; p = 0.015); and 3. the onset of upper esophageal sphincter opening occurred later after bolus entry into the pharynx for the swallowing cues condition (111.9ms vs. 103.31ms; p = 0.017); however, effect sizes were small (< 0.2). There was a significant interaction between cue condition and bolus volume on swallowing frequency, such that the mean number of swallows of 15ml boluses was slightly higher during the control condition than during the swallowing cues condition. There were no significant interactions on measures of timing, suggesting distinct mechanisms for the effect of bolus volume and cues on swallowing kinematics. Further research is needed to investigate the effects of different cue modalities and focus (internal vs. external) on swallowing physiology.

The spread of herds and horses into the Altai: How livestock and dairying drove social complexity in Mongolia.

The initial movement of herders and livestock into the eastern steppe is of great interest, as this region has long been home to pastoralist groups. Due to a paucity of faunal remains, however, it has been difficult to discern the timing of the adoption of domesticated ruminants and horses into the region, though recent research on ancient dairying has started to shed new light on this history. Here we present proteomic evidence for shifts in dairy consumption in the Altai Mountains, drawing on evidence from sites dating from the Early Bronze to the Late Iron Age. We compare these finds with evidence for the rise of social complexity in western Mongolia, as reflected in material remains signaling population growth, the establishment of structured cemeteries, and the erection of large monuments. Our results suggest that the subsistence basis for the development of complex societies began at the dawn of the Bronze Age, with the adoption of ruminant livestock. Investments in pastoralism intensified over time, enabling a food production system that sustained growing populations. While pronounced social changes and monumental constructions occurred in tandem with the first evidence for horse dairying, ~1350 cal BCE, these shifts were fueled by a long-term economic dependence on ruminant livestock. Therefore, the spread into the Mongolian Altai of herds, and then horses, resulted in immediate dietary changes, with subsequent social and demographic transformations occurring later.

Increased saccadic latency in Amblyopia: Oculomotor and attentional factors

Amblyopia is a neurodevelopmental disorder of vision that arises from disrupted binocular vision during early childhood. Delayed initiation of saccadic eye movements is an established feature of amblyopia. The present study investigated whether oculomotor and/or attentional factors contribute to increased amblyopic eye saccadic latencies. Participants with normal vision (n = 10) and amblyopia (n = 10; 4 anisometropia, 6 strabismic/mixed) performed visually-guided saccades to targets presented via a mirror haploscope. Eye movements were recorded for both eyes even under monocular viewing conditions. In Experiment 1, we measured the latency, amplitude gain and peak velocity of saccades as targets were presented binocularly, or monocularly. Saccadic latencies were significantly longer for both eyes when targets were presented to only the amblyopic eye compared to all other conditions. Saccade gain and main sequence rate constants were similar across groups for all viewing conditions. In Experiment 2, we tested the hypothesis that shifts of overt attention may be deficient when viewing with the amblyopic eye. We presented the fixation target to one eye and the subsequent peripheral target (saccadic error signal) to the other eye. Shifting saccadic targets between the eyes expedited saccadic latencies irrespective of which eye viewed the target in the amblyopia group. These findings indicate that oculomotor factors related to saccade generation are unlikely to be responsible for amblyopic eye saccadic latency delays. We propose that an impairment in the ability to disengage attention from a fixation target and orient to a peripheral target when both targets are seen by the amblyopic eye may contribute to increased saccadic latency.

Evaluation of biomechanics using different traction devices in distalization of maxillary molar with clear aligners: a finite element study

The study aimed to mechanically evaluate the tooth displacement of molar distalization by clear aligners combined with micro-implant through different traction devices using finite element analysis. A three-dimensional finite element model of complete maxillary dentition was constructed. Simultaneously move the maxillary first and second molars 0.2 mm distally at the height of 4 mm and 6 mm of micro-implant, and 150 g force was applied to button, precision cut and angelbutton respectively. Initial tooth movement in six different conditions of anterior tooth and molars was analyzed and calculated with ANSYS software. All the upper anterior tooth exhibited uncontrolled labial tipping and intrusion upon the six conditions, and the central incisor showed the largest tendency of crown labial inclination. Among the absolute values of crown-root displacement difference of the anterior tooth in sagittal direction, the angelbutton was the smallest, which means the torque control ability was superior to others. However, button played a more accurate role in the sagittal and vertical control of canine. With the increase of micro-implant height, the torque control ability of anterior tooth was decreased, but the intrusion trend increased. The controlled distal inclination with extrusion of the first molar and uncontrolled distal inclination with intrusion of the second molar were observed, and the angelbutton had more effective horizontal and vertical control on molars, which was close to bodily movement than others. As a new type of traction device, angelbutton has excellent anchorage control effect in clear aligners therapy of molar distalization, which further realizes the accurate expression of orthodontic force.

Unconscious Influences on "Free Will" Movement Initiation: Slow-wave Brain Stimulation and the Readiness Potential.

A central objective in the study of volition has been to identify how changes in neural activity relate to voluntary-"free will"-movement. The readiness potential (RP) is observed in the EEG as a slow-building signal that precedes action onset. Many consider the RP as a marker of an underlying preparatory process for initiating voluntary movement. However, the RP may emerge from ongoing slow-wave brain oscillations that influence the timing of movement initiation in a phase-dependent manner. Transcranial alternating current stimulation (tACS) enables brain oscillations to be entrained at the frequency of stimulation. We delivered tACS at a slow-wave frequency over frontocentral motor areas while participants (n = 30) performed a simple, self-paced button press task. During the active tACS condition, participants showed a tendency to initiate actions in the phase of the tACS cycle that corresponded to increased negative potentials across the frontocentral motor region. Comparisons of premovement EEG activity observed over frontocentral and central scalp electrodes showed earlier onset and increased amplitude of RPs from active stimulation compared with sham stimulation. This suggests that movement-related activity in the brain can be modulated by the delivery of weak, nonconsciously perceptible alternating currents over frontocentral motor regions. We present novel findings that support existing theories, which suggest the timing of voluntary movement is influenced by the phase of slow-changing oscillating brain states.

Movement-specific signaling is differentially distributed across motor cortex layer 5 projection neuron classes.

Motor cortex generates descending output necessary for executing a wide range of limb movements. Although movement-related activity has been described throughout motor cortex, the spatiotemporal organization of movement-specific signaling in deep layers remains largely unknown. Here we record layer 5B population dynamics in the caudal forelimb area of motor cortex while mice perform a forelimb push/pull task and find that most neurons show movement-invariant responses, with a minority displaying movement specificity. Using cell-type-specific imaging, we identify that invariant responses dominate pyramidal tract (PT) neuron activity, with a small subpopulation representing movement type, whereas a larger proportion of intratelencephalic (IT) neurons display movement-type-specific signaling. The proportion of IT neurons decoding movement-type peaks prior to movement initiation, whereas for PT neurons, this occurs during movement execution. Our data suggest that layer 5B population dynamics largely reflect movement-invariant signaling, with information related to movement-type being routed through relatively small, distributed subpopulations of projection neurons.

Influential Factors and Preliminary Reference Data for a Clinically Feasible, Functional Reaction Time Assessment: The Standardized Assessment of Reaction Time.

Clinical reaction-time (RT) measures are frequently used when examining patients with concussion but do not correlate with functional movement RT. We developed the Standardized Assessment of RT (StART) to emulate the rapid cognitive demands and whole-body movement needed in sport. To assess StART differences across 6 cognitive-motor combinations, examine potential demographic and health history confounders, and provide preliminary reference data for healthy collegiate student-athletes. Prospective, cross-sectional study. Clinical medicine facilities. A total of 89 student-athletes (56 [62.9%] men, 33 [37.1%] women; age = 19.5 ± 0.9 years, height = 178.2 ± 21.7 cm, mass = 80.4 ± 24 kg; no concussion history = 64 [71.9%]). Student-athletes completed health history questionnaires and StART during preseason testing. The StART consisted of 3 movements (standing, single-legged balance, and cutting) under 2 cognitive states (single task and dual task [subtracting by 6's or 7's]) for 3 trials under each condition. The StART trials were calculated as milliseconds between penlight illumination and initial movement. We used a 3 × 2 repeated-measures analysis of variance with post hoc t tests and 95% CIs to assess StART cognitive and movement differences, conducted univariable linear regressions to examine StART performance associations, and reported StART performance as percentiles. All StART conditions differed (P ≤ .03), except single-task standing versus single-task single-legged balance (P = .36). Every 1-year age increase was associated with an 18-millisecond (95% CI = 8, 27 milliseconds) slower single-task cutting RT (P < .001). Female athletes had slower single-task (15 milliseconds; 95% CI = 2, 28 milliseconds; P = .02) and dual-task (28 milliseconds; 95% CI = 2, 55 milliseconds; P = .03) standing RT than male athletes. No other demographic or health history factors were associated with any StART condition (P ≥ .056). The StART outcomes were unique across each cognitive-motor combination, suggesting minimal subtest redundancy. Only age and sex were associated with select outcomes. The StART composite scores may minimize confounding factors, but future researchers should consider age and sex when providing normative data.

Where you look during golf putting makes no difference to skilled golfers (but what you look at might!): an examination of occipital EEG ɑ-power during target and ball focused aiming

ABSTRACT This study probed a psycho-motor switch between “attention” and “intention” using electroencephalography (EEG) of the occipital cortex during target versus ball focused aiming when golf putting. Specifically, we investigated (1) the pattern and power of ɑ-frequency between putting methods at 8 and 15 ft. distances and (2) the EEG activity for missed versus holed putts. Twelve highly skilled golfers executed 32 putts in total using both methods (i.e., 8 putts per condition) under naturalistic and competitive conditions. Putting performance (number of putts holed and distance from the hole) and EEG activity at −6 s, −4 s and −2 s before movement initiation were recorded. No performance difference was found for holed or missed putts between the putting methods at either distance (p > 0.05). Overall, EEG data revealed a significant time effect, with higher power at −2 s for all conditions apart from at the most challenging 15 ft. distance when using ball focused aiming, where the power decreased. For missed putts at either distance, there was twice the artefact and eye blink during ball compared to target focused aiming. Data suggest a more robust switch from attention to intention when preparing for execution with target focused aiming. Target focused aiming suggestively helps golfers to remove a potential distraction, such as from seeing the arms, hand and ball, rather than offering any distinct/different advantage to ball focused aiming. In other words, a distraction caused by what the golfer looks at rather than where gaze is directed.

Women’s Leadership in Kazakhstan as a Driver of Social Maturation

Studies of women’s leadership in Kazakhstan suggest that there are informal leaders who are firmly associated with real activities aimed at solving specific problems of society, especially in the social sphere. The purpose of this article is to identify the factors, characteristics and specific forms of informal female leadership that have influenced the maturation of civil society in Kazakhstan in recent decades, defining the strategies that they use to establish cooperation with decision-­making government agencies and individuals. Our hypothesis is that the participation of women activists expands the opportunities and scope of the civil sector in providing assistance to the most vulnerable members of the community, if they use strategies and tools that change the attitudes and approaches of state structures to these social problems. During our case study, as research methods we used observation and analysis of the activities of several women leaders, initiators of social and charitable movements. The primary and secondary sources used were interviews, media materials, and reports on performance results, ongoing projects, as well as official information on a number of issues affecting our theme. We tested the theories of transformational and adaptive leadership, as well as the concept of social capital, put forward by foreign scientists to practice female leadership in Kazakhstan, and concluded that they can be applied with certain adjustments for local conditions. We believe that in certain areas, the activities of non-governmental organizations led by women leaders are becoming more effective than the work of official bodies, which indicates an increase in the potential of civil society.

Cerebellum encodes and influences the initiation, performance, and termination of discontinuous movements in mice.

The cerebellum is hypothesized to represent timing information important for organizing salient motor events during periodically performed discontinuous movements. To provide functional evidence validating this idea, we measured and manipulated Purkinje cell (PC) activity in the lateral cerebellum of mice trained to volitionally perform periodic bouts of licking for regularly allocated water rewards. Overall, PC simple spiking modulated during task performance, mapping phasic tongue protrusions and retractions, as well as ramping prior to both lick-bout initiation and termination, two important motor events delimiting movement cycles. The ramping onset occurred earlier for the initiation of uncued exploratory licking that anticipated water availability relative to licking that was reactive to water allocation, suggesting that the cerebellum is engaged differently depending on the movement context. In a subpopulation of PCs, climbing-fiber-evoked responses also increased during lick-bout initiation, but not termination, highlighting differences in how cerebellar input pathways represent task-related information. Optogenetic perturbation of PC activity disrupted the behavior by degrading lick-bout rhythmicity in addition to initiating and terminating licking bouts confirming a causative role in movement organization. Together, these results substantiate that the cerebellum contributes to the initiation and timing of repeated motor actions.

Long-term Complications of Previously Successful Regenerative Endodontic Procedures after Orthodontic Movement: A Report of 3 Different Complications after 4, 8, and 11 Years

There is a paucity of literature on late complications of regenerative endodontic procedures. The aim of this article was to report 3 cases of previously successful regenerative endodontic procedures with long-term follow-up that developed different complications after the application of orthodontic forces. In the first case, an 8-year-old female patient received a regenerative endodontic procedure in her previously intruded tooth (tooth no. 21) that had been rendered necrotic after a successful spontaneous repositioning procedure. The 5-year follow-up revealed uneventful healing, continuous root development, dentinal wall thickening, and regaining of pulp vitality for tooth no. 21. Four years later, the patient received orthodontic treatment with mild forces that lasted 2 years. The 11-year follow-up revealed severe external invasive cervical resorption, and the tooth had to be extracted. In the second case, a 6-year-old female patient suffered a lateral luxation injury in tooth no. 11. Six months after the injury, the tooth developed symptoms and discoloration and tested negative in pulp vitality testing. Single-step regenerative endodontic procedures were applied, and successful continuous root development, dentinal wall thickening, and apical closure were achieved at the 3-year follow-up. Two months after the initiation of orthodontic treatment, the tooth developed symptomatic apical periodontitis. Root canal treatment was performed to treat the disease, and the orthodontic treatment was continued. In the third case, a previously published successful regenerative endodontic procedure developed a perforating internal resorption 6 months after the application of orthodontic forces. The internal resorption was arrested with root canal treatment, the resorptive defect was repaired with bioceramic obturation, and the orthodontic treatment plan was modified. Previously successful regenerative cases might develop external invasive cervical resorption, regenerative tissue necrosis, or internal resorption after the application of orthodontic forces. Best practice/evidence-based guidelines on the appropriate orthodontic management of successful regenerative endodontic therapy teeth are lacking. Whenever possible, careful monitoring and partial or complete exclusion off orthodontic treatment might be necessary. In some cases, preventive root canal treatment before the initiation of orthodontic movement might be considered.

Binding and Retrieval of Response Durations: Subtle Evidence for Episodic Processing of Continuous Movement Features.

Re-encountering a stimulus retrieves nominally relevant, categorical response features related to previous action decisions in response to this stimulus. Whether binding and retrieval extend to nominally irrelevant, metric features relating to an actual body movement is unknown, however. In two experiments, we thus tested whether repeating target or distractor stimuli across trials retrieves the irrelevant duration of spatial responses to these stimuli. We found subtle indication of such retrieval by task-relevant target stimuli, suggesting that binding and retrieval also operate on metric features of a motor response. In contrast, there was no sign of binding and retrieval of metric features for distractor stimuli. We discuss these observations regarding the representation of action episodes during action-related decision making and during actual movement initiation and control.

18F-FDG 18F-FDG Positron Emission Tomography Imaging of Cortical Reorganization in Spinal Trauma.

Objective:Spinal cord injury (SCI) extensively impacts the sensorimotor reorganization in the brain. The effects can be both anatomical and functional. To date, not many studies using 18F-Fluoro-2-Deoxyglucose positron emission tomography (18F-FDG PET) to evaluate metabolic changes in the brain are done. Understanding such changes is crucial for developing clinical management and evidence-based rehabilitation strategies for these patients.Subjects and Methods:In this study, we compared 18F-FDG PET imaging of 6 SCI patients with complete paraplegia and 19 controls. Statistical parametric mapping software was utilized to compare the images on a voxel to voxel basis (significance level P < 0.05 and clusters having >50 voxels).Results:The study showed raised metabolism in supplementary motor areas, comprehension centers, some areas in the parietal and temporal lobe, putamen and cerebellum while reduced metabolic uptake in areas like anterior cingulate gyrus, hippocampus and sensory cortical areas when SCI patients were compared against healthy controls. The frontal lobe showed varied results where certain regions showed higher metabolism while the others showed lower in patients compared with controls.Conclusion:Cerebral deafferentation or disuse atrophy can be linked with reduced metabolism while raised uptake can be associated with initiation and planning of movement and cognitive changes in the brain posttrauma.