2-back task in split-belt adaptation

We studied split-belt treadmill adaptation and savings in young (21±2 y/o) and older (56±6 y/o) adults with or without a secondary 2-back task during adaptation. We here provide here kinematic data for split-belt treadmill walking - specifically, step length asymmetry, double support asymmetry, and limb excursion asymmetry measure. We provide raw response data (button presses and reaction time) for performance in the 2-back cognitive task. We also provide scripts that can be used to analyse motor and cognitive data using bootstrapping.

Methods
1. Description of methods used for collection/generation of data: 

Motor data was collected using Optotrak Motion Capture system at 100Hz, cognitive data was collected using MATLAB. Please refer to the manuscript for detailed methodology.

2. Methods for processing the data: 

For motor data, gaps in raw data were filled using the MATLAB function "interp1" with method "pchip". The data was filtered with a 4th order butterworth low pass filter with normalized cutoff frequency of 6/50. Then, heel strikes and toe offs were detected for each strided based on kinematic data. Heel strike was taken to be the position of the ankle furthest ahead in the direction of walking, and toe off was taken to be the position of the ankle furthest behind in the direction of walking. All other processing (including that for cognitive data) is described in the manuscript.