SPECIAL INTEREST REPORT POSTER DISPLAY

A DUAL-TASK TEST TO ASSESS DIVISION OF ATTENTION IN ELDERLY PEOPLE. Voos M¹, Castelli L¹, Andrade M¹, Teixeira P¹, Ribeiro do Valle L², Piemonte M¹; ¹Department of Speech, Physical Therapy and Occupational Therapy, Faculdade de Medicina, Universidade de São Paulo, São Paulo – Brazil. ²Department of Biomedical Sciences, Universidade de São Paulo, São Paulo – Brazil

PURPOSE: The aim of this study was to develop a test to assess the lower limbs control when divided attention was needed. The concurrent tasks were a visual and a motor activity (dual-task paradigm). RELEVANCE: It is important to verify if elderly people can walk in external places safely and detect the risk of accidents in order to prevent them. DESCRIPTION: The test was run in a room with reduced illumination, using a computer with the applicative MEL2, an adapted joystick, a 10cm platform fixed on the ground and a video camera. The test consisted on (1) training session; (2) visual task; (3) motor task; (4) both tasks associated. The visual task was based on the Useful Field Of View test. It measured the accuracy of recognition of two 150 ms visual targets (bus and/or truck) presented simultaneously: one appearing at the fixation cross (center) and one in one of eight positions (periphery). The volunteers had to classify if the targets were equal or different. The answers were typed on an adapted joystick, by the examiner (32 trials). The program registered the number of errors and the total duration of the visual task. The motor task consisted on alternating steps from the ground to a 10cm platform, as fast as possible. The alternations were videotaped and counted. The motor and visual tasks had the same duration. EVALUATION: Thirteen elderly (71.08±2.34 years of age) and thirteen young volunteers (25.54±1.26 years of age) participated in this study. They performed the dual-task and the Trail Making Test (TMT) – Parts A and B. TMT demands more attention in part B (letters and numbers) than in part A (letters). The number of steps per second in the absence and the presence of the visual task, the number of errors in the absence and the presence of the motor task (dual-task) and the difference between parts A and B (TMT) were analyzed by ANOVAs (α=0.05). In the dual-task, volunteers were slower in the motor task when the visual task was introduced [F(1,24) = 37.074; p < 0.001], but did not commit more errors in the visual task when the motor task was introduced [F(1,24) = 0.283; p = 0.599]. In part B (TMT), volunteers were slower than in part A [F(1,24) = 29.691; p < 0.001]. In both tests, elderly were slower than young volunteers [F(1,24) = 69.072, p < 0.001 (dual-task); F(1,24) = 30.762, p < 0.001 (TMT)]. CONCLUSIONS: Both tests evidenced reduction of speed when the complexity increased. The dual-task detected difficulties in lower limbs control when speed and division of attention was needed, but failed to detect increase in the number of errors in the visual task when the motor task was introduced, probably because the visual task had a high level of complexity and was difficult for the elderly even when performed separately. IMPLICATIONS: The dual-task test could be used as a complementary tool to verify the level of automaticity in lower limbs control. In future studies we intend to increase the difference between the visual stimuli to simplify the visual task. KEYWORDS: perceptual motor performance, dual-task, aging. FUNDING ACKNOWLEDGEMENTS: this work was unfunded. CONTACT: marivoos@usp.br

ETHICS COMMITTEE: This study was approved by the Institute of Biomedical Sciences Ethics Committee – Universidade de São Paulo (Brazil).