Assessing specificity of motor learning under conditions of neuromuscular fatigue


This experiment assessed how motor skills developed under a specific sensorimotor context (neuromuscular arm fatigue) transfer to performance situations that differ from that acquisition environment. Data were collected on 36 participants (age M= 27.3, SD= 3.4) split equally into fatigue or no-fatigue groups. Participants in the fatigue group used a hand-grip dynamometer to physically fatigue their forearm after every 20 of 80 trials of a motor task consisting of drawing a waveform using only wrist flexion and extension on a mouse trackpad. The dependent variables of interest were Root Mean Square Error (RMSE) and Movement Time (MT). Following acquisition, an immediate retention test, delayed retention test, and transfer test were used to assess motor learning and motor skill specificity or generalizability. During the transfer test, the fatigue group performed the motor task under no-fatigue for the first time (vice versa for the no-fatigue group). Contrary to our hypothesis that a decrement in transfer performance would be evident (see also Proteau et al, 1987; 1992; 1998; 2002) results revealed no significant main effects or interactions involving group suggesting that motor learning, at least under these constrained conditions, is not dependent upon, nor specific to, the sensorimotor context under which this learning occurs. This evidence is thus inconsistent with the idea (cf. Proteau et al, 1987; 1992; 1998; 2002) that motor learning is mediated by the development, during task acquisition, of task specific sensorimotor representations that integrate information from central processes with the sensory feedback acquired from previous experiences on that task.

Acknowledgments: NSERC