Motor and Neural Adaptation during an Eight-Week Writing Training with the Non-Preferred Hand

摘要

Drawing on the work of Haken et al. (1985) and Hollerbachs oscillatory handwriting model (1981), Athenes et al. (2004) showed that graphomotor skills are governed by nonlinear dynamic coupling of two (nearly) orthogonal oscillators, measured as relative phase (RP). Other studies evaluated the degree of automaticity by means of kinematic parameters, e.g. the number of velocity inversions (NIV) per stroke (Mai and Marquardt, 1998). Electrophysiological and neuroimaging studies showed that motor training produced altered activity in task-related brain-areas, in both early and later stages (Patel et al., 2013; Bar and DeSouza, 2016). In the present study, we investigated the development of RP, velocity, and NIV of the letter "e" during eight weeks of training to write with the non-preferred hand, as well as changes in spectral maps of the cortex in three of the nine sessions. By applying an exploratory longitudinal single case study design to the task, we hope to gather new insights about individual motor and neural adaptation. We hypothesized that writing velocity and automaticity increase with training, while RP becomes more stable. Furthermore, subjects should show enhanced neural activity in task related regions. Areas disengaging in later stages could play a role during early learning.