Evaluation of speed-accuracy trade-off in a computer task in individuals with cerebral palsy: a cross-sectional study

Deborah Cristina Gonçalves Luiz Fernani, Maria Tereza Artero Prado, Talita Dias da Silva, Thais Massetti, Luiz Carlos de Abreu, Fernando Henrique Magalhães, Helen Dawes, Carlos Bandeira de Mello Monteiro

Individuals with Cerebral Palsy (CP) present with sensorimotor dysfunction which make the control and execution of movements difficult. This study aimed to verify the speed-accuracy trade-off in individuals with CP. Forty eight individuals with CP and 48 with typical development (TD) were evaluated (32 females and 64 males with a mean age of 15.02 ± 6.37 years: minimum 7 and maximum 30 years). Participants performed the "Fitts' Reciprocal Aiming Task v.1.0 (Horizontal)" on a computer with different sizes and distance targets, composed by progressive indices of difficulty (IDs): ID2, ID4a and ID4b. There were no statistical differences between the groups in relation to the slope of the curve (b1) and dispersion of the movement time (r(2)). However, the intercept (b0) values presented significant differences (F(1.95) = 11.3; p = .001]), with greater movement time in the CP group compared to the TD group. It means that for individuals with CP, regardless of index difficulty, found the task more difficult than for TD participants. Considering CP and TD groups, speed-accuracy trade-off was found when using different indices of difficulty (ID2 and ID4). However, when the same index of difficulty was used with a larger target and longer distance (ID4a) or with a narrow target and shorter distance (ID4b), only individuals with CP had more difficulty performing the tasks involving smaller targets. Marginally significant inverse correlations were identified between the values of b1 and age (r = -0.119, p = .052) and between r(2) and Gross Motor Function Classification System (r = -0.280, p = .054), which did not occur with the Manual Ability Classification System. We conclude that the individuals with CP presented greater difficulty when the target was smaller and demanded more accuracy, and less difficulty when the task demanded speed. It is suggested that treatments should target tasks with accuracy demands, that could help in daily life tasks, since it is an element that is generally not considered by professionals during therapy. ClinicalTrials.gov, NCT03002285 , retrospectively registered on 20 Dec 2016.