SPECIAL INTEREST REPORT POSTER DISPLAY

ANALYSIS OF THE DUAL-TASK PARADIGM: ATTENTION X MAINTENANCE OF POSTURE. Abbud G^1,2, Sa C^3,4, Ramos R⁴, Boffino C⁴; ¹Concordia University, Montreal Canada. ²University of Sao Paulo, Sao Paulo Brazil. ³IMES University Sao Paulo Brazil. ⁴Psychiatry Institut HC-FMUSP Sao Paulo Brazil

PURPOSE: Maintenance of posture uses musculoskeletal and neural mechanisms, but interaction of the visual, vestibular and somatossensory systems are responsible for the muscular adjustments leading to balance. Dual-task (DT) paradigms have demonstrated that attentional demand can compete with the maintenance of balance. Our purpose was to determine the effects of a visual attentional tracking task on balance. RELEVANCE: In rehabilitation routine we frequently expose patients to activities involving division of attentional resources (DT paradigms). We expect our patients to develop the ability to perform these activities without decreased performance and we train them to perform DT activities, as they will face them on their daily living. However, it is not clear if attentional division can be learned or improved. Furthermore, it is necessary to clarify what is involved in this paradigm and the compensations or adaptations of the motor system related to it. PARTICIPANTS: 20 male and female voluntarily consented to participate in the study (age mean=23.2 years). METHODS: Volunteers were submitted to the Modified Sensory-Organization Test (MSOT), which is a dynamic computer-based posturography test (NeuroCom^®). Balance performance was compared in two different conditions: eyes open/fixed surface and eyes open/sway referenced surface, with and without performing the attentional visual tracking task (COGNITIVO^®). The tracking task consisted in maintaining a circle, controlled with a joystick by the volunteers, inside a rectangle that was continuously and randomly moving horizontally on the computer screen. ANALYSIS: We compared (student t-test) their balance performance under the two conditions. Their performance on the visual tracking task was obtained by the percentage of time the circle was kept inside the rectangle, and also compared using the t-test. A significance level of p < 0.05 was used. RESULTS: The balance score under the condition eyes open/sway referenced surface was significantly reduced during the attentional tracking task performance (mean=82.77 ±3.99; mean=85.75 ±5.21; p = 0.037). However, there was no statistical difference under the condition eyes open/ fixed surface (mean=94.73 ±1.21; mean 94.10 ±1.40; p = 0.118). There was no statistical difference for both conditions on the performance of the attentional task (mean=24.20; ±3.26; mean= 24.11 ±3.59; p = 0.853). CONCLUSIONS: This study confirmed the effect of the dual-task paradigm under the condition eyes open/sway referenced surface. In this condition, the attentional resources were directed to the visual task rather than to the maintenance of posture, leading to poorer balance performance of the volunteers. However, it does not occur under the condition eyes opens/fixed surface, possibly because the maintenance of static posture may not be a challenging activity for normal subjects to demonstrate attentional sharing by reduced performance. IMPLICATIONS: Physiotherapists should expect altered performance from their patients when submitted to attentional sharing activities, however, it is important to emphasis that it tends to occur if the activities proposed are challenging enough. It is necessary to develop further comparisons between normal and individuals with motor impairments to understand attentional sharing and possible compensations and adaptations in more depth. KEYWORDS: Dual-task paradigm, balance, posturography. FUNDING ACKNOWLEDGEMENTS: None. CONTACT: gabriela.abbud@gmail.com

ETHICS COMMITTEE: ethics Committe from Hospital das Clinica, Sao Paulo, Brazil