4 resultados para SENSORIMOTOR SYNCHRONIZATION

em Brock University, Canada


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It is estimated that five to ten percent of children experience sensory motor difficulties that result in various learnlng disabilitiies , among them. inabllity to output Information on paper in the appropriate manner (Ayres ,1985). The relationship between sensorimotorabillty and handwriting is well documented in the literature (Freeman,1917; Townsend , 1951; Nlkola-Ll sa, 1987). While much of the literature is inconclusive, there are findings to suggest that muitisensory handwriting programmes are an effective approach to improvlng writing abIlity in these chlldren. For a number of years, Occupational Therapists have been involved in the remediation of handwriting utllizing , amongst other approaches . multisensory programmes. While subjective assessments of effectiveness have been extremerly positive. scientIfic evaluation has been minimal . If further intervention in this area is to occur, it Is essential that the profession be able to justify the existence of such programmes . The purpose of this study was to examine what effects a multlsensory writing prog~am would have on the curslve writing ability of chlldren with sensorimotor dlfficulties. A single case with multiple baselines across be havlours design was used , with the behavlours being cursive writing abilIty of fIve distInct letter groups. The fIve groups were taught in random order, one group every two weeks , In a one-hour session. Repeated measurements of writing speed and qualIty for each letter group were made. This design was repeated over three other cases . Results of the study yielded statistical signifi cance in trend changes In specIfic letter groups for all of the chlldren following interventlon. One child achieved statistical significance In the overall change In quality , while none of the children achieved overall statistical significance In speed score changes . Teacher reports and an assessment of written language prior to and following the program suggest that Intervention may have had a positive effect on self-confidence in written output, and on the maturlty of written expression in some of the cases . Further research in this field is needed to validate the continual use of multisensory writing programmes by Occupational Theraplsts worklng with this specific population and to provide some directlon with regards to the Integration of multlsensory writing programmes within the regular academic remedial programme .

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The oscillation of neuronal circuits reflected in the EEG gamma frequency may be fundamental to the perceptual process referred to as binding (the integration of various thoughts and perceptions into a coherent picture). The aim of our study was to expand our knowledge of the developmental course ofEEG gamma in the auditory modality. 2 We investigated EEG 40 Hz gamma band responses (35.2 to 43.0 Hz) using an auditory novelty oddball paradigm alone and with a visual-number-series distracter task in 208 participants as a function of age (7 years to adult) at 9 sites across the sagital and lateral axes (F3, Fz, F4, C3, Cz, C4, P3, Pz, P4). Gamma responses were operationally defined as change in power or a change in phase synchrony level from baseline within two time windows. The evoked gamma response was defined as a significant change from baseline occurring between 0 to 150 ms after stimulus onset; the induced gamma response was measured from 250 to 750 ms after stimulus onset. A significant evoked gamma band response was found when measuring changes in both power and phase synchrony. The increase in both measures was maximal at frontal regions. Decreases in both measures were found when participants were distracted by a secondary task. For neither measure were developmental effects noted. However, evoked gamma power was significantly enhanced with the presentation of a novel stimulus, especially at the right frontal site (F4); frontal evoked gamma phase synchrony also showed enhancement for novel stimuli but only for our two oldest age groups (16-18 year olds and adults). Induced gamma band responses also varied with task-dependent cognitive stimulus properties. In the induced gamma power response in all age groups, target stimuli generated the highest power values at the parietal region, while the novel stimuli were always below baseline. Target stimuli increased induced synchrony in all regions for all participants, but the novel stimulus selectively affected participants dependent on their age and gender. Adult participants, for example, exhibited a reduction in gamma power, but an increase in synchrony to the novel stimulus within the same region. Induced gamma synchrony was more sensitive to the gender of the participant than was induced gamma power. While induced gamma power produced little effects of age, gamma synchrony did have age effects. These results confirm that the perceptual process which regulates gamma power is distinct from that which governs the synchronization for neuronal firing, and both gamma power and synchrony are important factors to be considered for the "binding" hypothesis. However, there is surprisingly little effect of age on the absolute levels of or distribution of EEG gamma in the age range investigated.

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The main objective of this research was to examine the relationship between surface electromyographic (SEMG) spike activity and force. The secondary objective was to determine to what extent subcutaneous tissue impacts the high frequency component of the signal, as well as, examining the relationship between measures of SEMG spike shape and their traditional time and frequency analogues. A total of96 participants (46 males and 50 females) ranging in age (18-35 years), generated three 5-second isometric step contractions at each force level of 40, 60, 80, and 100 percent of maximal voluntary contraction (MVC). The presentation of the contractions was balanced across subjects. The right arm of the subject was positioned in the sagittal plane, with the shoulder and elbow flexed to 90 degrees. The elbow rested on a support in a neutral position (mid pronation/mid supination) and placed within a wrist cuff, fastened below the styloid process. The wrist cuff was attached to a load cell (JR3 Inc., Woodland, CA) recording the force produced. Biceps brachii activity was monitored with a pair of Ag/AgCI recording electrodes (Grass F-E9, Astro-Med Inc., West Warwick, RI) placed in a bipolar configuration, with an interelectrode distance (lED) of 2cm distal to the motor point. Data analysis was performed on a I second window of data in the middle of the 5-second contraction. The results indicated that all spike shape measures exhibited significant (p < 0.01) differences as force increase~ from 40 to 100% MVC. The spike shape measures suggest that increased motor unit (MU) recruitment was responsible for increasing force up to 80% MVC. The results suggested that further increases in force relied on MU III synchronization. The results also revealed that the subcutaneous tissue (skin fold thickness) had no relationship (r = 0.02; P > 0.05) with the mean number of peaks per spike (MNPPS), which was the high frequency component of the signal. Mean spike amplitude (MSA) and mean spike frequency (MSF) were highly correlated with their traditional measures root mean square (RMS) and mean power frequency (MPF), respectively (r = 0.99; r = 0.97; P < 0.01).

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Synchronization of behaviour between individuals has been found to result in a variety of prosocial outcomes. The role of endorphins in vigorous synchronous activities (Cohen, Ejsmond-Frey, Knight, & Dunbar, 2010) may underlie these effects as endorphins have been implicated in social bonding (Dunbar & Shultz, 2010). Although research on synchronous behaviour has noted that there are two dominant phases of synchrony: in-phase and anti-phase (Marsh, Richardson, Baron, & Schmidt, 2006), research on the effect of synchrony on endorphins has only incorporated in-phase synchrony. The current study examined whether both phases of synchrony would generate the synchrony effect. Twenty-two participants rowed under three counterbalanced conditions - alone, in-phase synchrony and anti-phase synchrony. Endorphin release, as measured via pain threshold, was assessed before and after each session. Change in pain threshold during the in-phase synchrony session was significantly higher than either of the other two conditions. These results suggest that the synchrony effect may be specific to just in-phase synchrony, and that social presence is not a viable explanation for the effect of synchrony on pain threshold