Effect of instructive visual stimuli on neurofeedback training for motor imagery-based braincomputer interface

Event-related desynchronization (ERD) of the electroencephalogram (EEG) from the motor cortex is associated with execution, observation, and mental imagery of motor tasks. Generation of ERD by motor imagery (MI) has been widely used for brain-computer interfaces (BCIs) linked to neuroprosthetics and other motor assistance devices. Control of MI-based BCIs can be acquired by neurofeedback training to reliably induce MI-associated ERD. To develop more effective training conditions, we investigated the effect of static and dynamic visual representations of target movements (a picture of forearms or a video clip of hand grasping movements) during the BCI training. After 4 consecutive training days, the group that performed MI while viewing the video showed significant improvement in generating MI-associated ERD compared with the group that viewed the static image. This result suggests that passively observing the target movement during MI would improve the associated mental imagery and enhance MI-based BCIs skills.

Visual processing of optic flow and motor control in the human posterior cingulate sulcus

Previous studies have shown that the human posterior cingulate contains a visual processing area selective for optic flow (CSv). However, other studies performed in both humans and monkeys have identified a somatotopic motor region at the same location (CMA). Taken together, these findings suggested the possibility that the posterior cingulate contains a single visuomotor integration region. To test this idea we used fMRI to identify both visual and motor areas of the posterior cingulate in the same brains and to test the activity of those regions during a visuomotor task. Results indicated that rather than a single visuomotor region the posterior cingulate contains adjacent but separate motor and visual regions. CSv lies in the fundus of the cingulate sulcus, while CMA lies in the dorsal bank of the sulcus, slightly superior in terms of stereotaxic coordinates. A surprising and novel finding was that activity in CSv was suppressed during the visuomotor task, despite the visual stimulus being identical to that used to localize the region. This may provide an important clue to the specific role played by this region in the utilization of optic flow to control self-motion.

MiR-375 is essential for human spinal motor neuron development and may be involved in motor neuron degeneration

The transcription factor REST is a key suppressor of neuronal genes in non-neuronal tissues. REST has been shown to suppress pro-neuronal microRNAs in neural progenitors indicating that REST-mediated neurogenic suppression may act in part via microRNAs. We used neural differentiation of Rest-null mouse ESC to identify dozens of microRNAs regulated by REST during neural development. One of the identified microRNAs, miR-375, was upregulated during human spinal motor neuron development. We found that miR-375 facilitates spinal motor neurogenesis by targeting the cyclin kinase CCND2 and the transcription factor PAX6. Additionally, miR-375 inhibits the tumor suppressor p53 and protects neurons from apoptosis in response to DNA damage. Interestingly, motor neurons derived from a spinal muscular atrophy patient displayed depressed miR-375 expression and elevated p53 protein levels. Importantly, SMA motor neurons were significantly more susceptible to DNA damage induced apoptosis suggesting that miR-375 may play a protective role in motor neurons.

Effect of substrate on the locomotion behaviour of the South American iguanian lizard Polychrus acutirostris

Arboreal and terrestrial habitats impose different constraints on tetrapod locomotion. We studied Polychrus acutirostris, a tree-dwelling lizard that also moves on the ground, in order to evaluate the effects of support incline and diameter on locomotion parameters. Limb movements of six specimens were filmed to quantify kinematic variables (velocity, stride frequency, stride length, and limb coordination) on distinct perch diameters (4.0, 1.5, 0.8 cm) and inclines (90, 45, and on level ground). The results show a notable slowness in arboreal habitat combined with a relatively fast locomotion when using the ground as temporary habitat. These animals developed walking trots mainly using lateral sequence. Non-symmetrical trots adopted at the highest velocities on the ground indicate difficulties of ""accommodation"" to the constraints imposed by this condition. Velocity generally decreases with the decreasing diameter, and with increasing incline, of the supports. Slowness, gaits favouring the body stability, elective role of the stride frequency in the modulation of the speed, and the role of the hindlimb in the force exchange to propel the body, constitute the main features of the locomotion pattern of P. acutirostris.

Locomotion patterns in two South American gymnophthalmid lizards: Vanzosaura rubricauda and Procellosaurinus tetradactylus

We quantified gait and stride characteristics (velocity, frequency, stride length, stance and swing duration, and duty factor) in the bursts of locomotion of two small, intermittently moving, closely related South American gymnophthalmid lizards: Vanzosaura rubricauda and Procellosaurinus tetradactylus. They occur in different environments: V rubricauda is widely distributed in open areas with various habitats and substrates, while P. tetradactylus is endemic to dunes in the semi-arid Brazilian Caatinga. Both use trot or walking trot characterised by a lateral sequence. For various substrates in a gradient of roughness (perspex, cardboard, sand, gravel), both species have low relative velocities in comparison with those reported for larger continuously moving lizards. To generate velocity, these animals increase stride frequency but decrease relative stride length. For these parameters, P. tetradactylus showed lower values than V rubricauda. In their relative range of velocities, no significant differences in stride length and frequency were recorded for gravel. However, the slopes of a correlation between velocity and its components were lower in P. tetradactylus on cardboard, whereas on sand this was only observed for velocity and stride length. The data showed that the difference in rhythmic parameters between both species increased with the smoothness of the substrates. Moreover, P. tetradactylus shows a highly specialised locomotor strategy involving lower stride length and frequency for generating lower velocities than in V. rubricauda. This suggests the evolution of a central motor pattern generator to control slower limb movements and to produce fewer and longer pauses in intermittent locomotion. (c) 2008 Elsevier GmbH. All rights reserved.

A web-based system for visualizing upper limb motor performance of Parkinson’s disease patients

Objective To design, develop and set up a web-based system for enabling graphical visualization of upper limb motor performance (ULMP) of Parkinson’s disease (PD) patients to clinicians. Background Sixty-five patients diagnosed with advanced PD have used a test battery, implemented in a touch-screen handheld computer, in their home environment settings over the course of a 3-year clinical study. The test items consisted of objective measures of ULMP through a set of upper limb motor tests (finger to tapping and spiral drawings). For the tapping tests, patients were asked to perform alternate tapping of two buttons as fast and accurate as possible, first using the right hand and then the left hand. The test duration was 20 seconds. For the spiral drawing test, patients traced a pre-drawn Archimedes spiral using the dominant hand, and the test was repeated 3 times per test occasion. In total, the study database consisted of symptom assessments during 10079 test occasions. Methods Visualization of ULMP The web-based system is used by two neurologists for assessing the performance of PD patients during motor tests collected over the course of the said study. The system employs animations, scatter plots and time series graphs to visualize the ULMP of patients to the neurologists. The performance during spiral tests is depicted by animating the three spiral drawings, allowing the neurologists to observe real-time accelerations or hesitations and sharp changes during the actual drawing process. The tapping performance is visualized by displaying different types of graphs. Information presented included distribution of taps over the two buttons, horizontal tap distance vs. time, vertical tap distance vs. time, and tapping reaction time over the test length. Assessments Different scales are utilized by the neurologists to assess the observed impairments. For the spiral drawing performance, the neurologists rated firstly the ‘impairment’ using a 0 (no impairment) – 10 (extremely severe) scale, secondly three kinematic properties: ‘drawing speed’, ‘irregularity’ and ‘hesitation’ using a 0 (normal) – 4 (extremely severe) scale, and thirdly the probable ‘cause’ for the said impairment using 3 choices including Tremor, Bradykinesia/Rigidity and Dyskinesia. For the tapping performance, a 0 (normal) – 4 (extremely severe) scale is used for first rating four tapping properties: ‘tapping speed’, ‘accuracy’, ‘fatigue’, ‘arrhythmia’, and then the ‘global tapping severity’ (GTS). To achieve a common basis for assessment, initially one neurologist (DN) performed preliminary ratings by browsing through the database to collect and rate at least 20 samples of each GTS level and at least 33 samples of each ‘cause’ category. These preliminary ratings were then observed by the two neurologists (DN and PG) to be used as templates for rating of tests afterwards. In another track, the system randomly selected one test occasion per patient and visualized its items, that is tapping and spiral drawings, to the two neurologists. Statistical methods Inter-rater agreements were assessed using weighted Kappa coefficient. The internal consistency of properties of tapping and spiral drawing tests were assessed using Cronbach’s α test. One-way ANOVA test followed by Tukey multiple comparisons test was used to test if mean scores of properties of tapping and spiral drawing tests were different among GTS and ‘cause’ categories, respectively. Results When rating tapping graphs, inter-rater agreements (Kappa) were as follows: GTS (0.61), ‘tapping speed’ (0.89), ‘accuracy’ (0.66), ‘fatigue’ (0.57) and ‘arrhythmia’ (0.33). The poor inter-rater agreement when assessing “arrhythmia” may be as a result of observation of different things in the graphs, among the two raters. When rating animated spirals, both raters had very good agreement when assessing severity of spiral drawings, that is, ‘impairment’ (0.85) and irregularity (0.72). However, there were poor agreements between the two raters when assessing ‘cause’ (0.38) and time-information properties like ‘drawing speed’ (0.25) and ‘hesitation’ (0.21). Tapping properties, that is ‘tapping speed’, ‘accuracy’, ‘fatigue’ and ‘arrhythmia’ had satisfactory internal consistency with a Cronbach’s α coefficient of 0.77. In general, the trends of mean scores of tapping properties worsened with increasing levels of GTS. The mean scores of the four properties were significantly different to each other, only at different levels. In contrast from tapping properties, kinematic properties of spirals, that is ‘drawing speed’, ‘irregularity’ and ‘hesitation’ had a questionable consistency among them with a coefficient of 0.66. Bradykinetic spirals were associated with more impaired speed (mean = 83.7 % worse, P < 0.001) and hesitation (mean = 77.8% worse, P < 0.001), compared to dyskinetic spirals. Both these ‘cause’ categories had similar mean scores of ‘impairment’ and ‘irregularity’. Conclusions In contrast from current approaches used in clinical setting for the assessment of PD symptoms, this system enables clinicians to animate easily and realistically the ULMP of patients who at the same time are at their homes. Dynamic access of visualized motor tests may also be useful when observing and evaluating therapy-related complications such as under- and over-medications. In future, we foresee to utilize these manual ratings for developing and validating computer methods for automating the process of assessing ULMP of PD patients.

Desempenho motor de pacientes com acidente vascular cerebral em um jogo baseado em realidade virtual

The Cerebral Vascular Accident (CVA) is the leading cause of motor disability in adults and elderly and that is why it still needs effective interventions that contribute to motor recovery. Objective: This study was aimed to evaluate the performance of stroke patients in chronic stage using a virtual reality game. Method: 20 patients (10 with injury to the left and 10 to the right side), right-handed, average age 50.6 ± 9.2 years, and 20 healthy subjects with average age of 50.9 ± 8.8, also right-handed participated. The patients had a motor (Fugl-Meyer) and muscle tone assessment (Ashworth). All participants made a kinematic evaluation of the drinking water activity and then underwent training with the table tennis game on XBOX 360 Kinect®, 2 sets of 10 attempts for 45 seconds, 15 minutes rest between sets, giving a total of 30 minutes session. After training the subjects underwent another kinematic evaluation. The patients trained with the right and left hemiparect upper limb and the healthy ones with the right and left upper limb. Data were analyzed by ANOVA, t Student test and Pearson correlation. Results: There was significant difference in the number of hits between the patients and healthy groups, in which patients had a lower performance in all the attempts (p = 0.008), this performance was related to a higher level of spasticity (r = - 0.44, p = 0.04) and greater motor impairment (r = 0.59, p = 0.001). After training, patients with left hemiparesis had improved shoulder and elbow angles during the activity of drinking water, approaching the pattern of motion of the left arm of healthy subjects (p < 0.05), especially when returning the glass to the table, and patients with right hemiparesis did not obtain improved pattern of movement (p > 0.05). Conclusion: The stroke patients improved their performance over the game attempts, however, only patients with left hemiparesis were able to increase the angle of the shoulder and elbow during the functional activity execution, better responding to virtual reality game, which should be taken into consideration in motor rehabilitation

LEARNING A COMPLEX MOTOR SKILL FROM VIDEO and POINT-LIGHT DEMONSTRATIONS

The aim of this Study was to compare the learning process of a highly complex ballet skill following demonstrations of point light and video models 16 participants divided into point light and video groups (ns = 8) performed 160 trials of a pirouette equally distributed in blocks of 20 trials alternating periods of demonstration and practice with a retention test a day later Measures of head and trunk oscillation coordination d1 parity from the model and movement time difference showed similarities between video and point light groups ballet experts evaluations indicated superiority of performance in the video over the point light group Results are discussed in terms of the task requirements of dissociation between head and trunk rotations focusing on the hypothesis of sufficiency and higher relevance of information contained in biological motion models applied to learning of complex motor skills

Characterization of the motor performance in infants with a diagnosis of Cerebral Palsy in process of rehabilitation: the importance of the proactivity of caregivers

Introduction: The progress in technology, associated to the high survival rate in premature newborn infants in neonatal intensive care units, causes an increase in morbidity. Individuals with CP present complex motor alterations, with primary deficits of abnormal muscle tone affecting posture and voluntary movement, alteration of balance and coordination, decrease of force, and loss of selective motor control with secondary problems of contractures and bone deformities.Objective: The aim of this work is to describe the spontaneous movement and strategies that lead infants with cerebral palsy to move.Methods: Seven infants used to receive assistance at the Essential Stimulation Center of CIAM (Israeli Center for Multidisciplinary Support - Philanthropic Institution), with ages ranging between six and 18 months with diagnosis of Cerebral Palsy (CP) were assessed.Results: The results show the difficulty presented by the infants with respect to the spontaneous motor functions and the necessity of help from the caregiver in order to perform the functional activity (mobility). Prematurity prevails as the major risk factor among the complications.Conclusion: The child development can be understood as a product of the dynamic interactions involving the infant, the family, and the context. Thus, the social interactions and family environment in which the infant live may encourage or limit both the acquisition of skills and the functional independence.

Report of a human accident caused by Conus regius (Gastropoda, Conidae)

Conus regius is a venomous mollusc in the Conidae family, which includes species responsible for severe or even fatal accidents affecting human beings. This is the first report on a clinical case involving this species. It consisted a puncture in the right hand of a diver who presented paresthesia and movement difficulty in the whole limb. The manifestations disappeared after around twelve hours, without sequelae.

Motor perseveration during an A not B task in children with intellectual disabilities

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Perception-action coupling in infants with down syndrome: Effects of experience and practice

This study examined the effects of experience and practice on the coupling between visual information and trunk sway in infants with Down syndrome (DS). Five experienced and five novice sitters were exposed to a moving room, which was oscillated at 0.2 and 0.5 Hz. Infants remained in a sitting position and data were collected on the first, fourth, and seventh days. On the first day, experienced sitters were more influenced by room oscillation than were novices. On the following days, however, the influence of room oscillation decreased for experienced but increased for novice sitters. These results suggest that the relationship between sensory information and motor action in infants with DS can be changed with experience and practice.

Síntomas depresivos y trastorno motor en pacientes con enfermedad de Parkinson

Introduction. Complex relations between brain and psychopathology have attracted the interest of researchers, aiming to clarify the neurobiological mechanisms of depression in Parkinson's disease, obviously in addiction to mental features. Aims. The association of motor impairment and decline of personal autonomy with severity of depressive symptoms was the hypothesis of the present study. Aiming to check this hypothesis, the objective of this study consisted in investigating relationships between the severity of depressive symptoms and motor characteristics of Parkinson's disease. Patients and methods. Thirty patients (53 to 80 year-old) with medical diagnosis of idiopathic Parkinson's disease in initial clinic stages were studied. The Unified Parkinson's Disease Rating Scale, Hoehn-Yahr Scale, and Schwab & England Scale were used to assess the clinic signs and symptoms. The depressive symptoms were identified by complete anamnesis, examination of mental condition, and the Hamilton Rating Scale for Depression and the Anxiety and Depression Scale. Statistical analysis was performed by Pearson's correlation and multiple regression analysis. Results. A significant correlation of severity of depression symptoms with disease stage (p < 0.02), with motor signs (p < 0.008), and with functional performance (p < 0.007) was found. Conclusion. There was significant association between motor impairment and severity of depressive symptoms, and between depression and early disease onset or prolonged duration of Parkinson's disease. © 2007, Revista de Neurología.

Do men and women use similar adaptive locomotion to clear static and dynamic obstacles?

Purpose. The purpose of this study was to analyze the influence of gender on the adaptive locomotion in the clearance of obstacles. Specifically, it was evaluated if there are differences in the space-temporal parameters between male and female in the clearance of and dynamic obstacles moving at both slow and fast speeds. Basic procedures. Five young male adults and five young female adults took part in this study. The task was performed in three conditions: static obstacle and dynamic obstacle - clearance perpendicular to the participant's trajectory at slow speed (1.07 m/s) and at fast speed (1.71 m/s). The trials were recorded by two digital cameras and spatial-temporal information was obtained. Main findings. The dynamic obstacle conditions required more visual inspection. The results showed different adaptive locomotion between the sexes. The distinct gait patterns were evidenced for the spatial and temporal variables and cadence in the three conditions. Conclusions. The women presented a more conservative behavior, which was evidenced by the increase of the length in the penultimate step and in the toe clearance.