Extrinsic feedback facilitates mental chronometry abilities in stroke patients

Motor imagery (MI) can serve as a treatment for stroke rehabilitation. MI abilities can be assessed by testing mental chronometry (MC) as the degree of conformity between imagined and real performance of a task. A good MC performance is supposed to indicate good MI capacities.

To explore if MC abilities can be modified by extrinsic feedback in stroke patients.

60 subacute stroke patients were randomized into three groups. MC was evaluated by executing a modified version of the Box and Block Test (BBT) mentally and in real before and after a training session. For Groups 1 and 2 the training consisted of repeated performance of the BBT in a mental and then a real version. The time needed to complete each task was measured. Only participants of Group 1 received feedback about how well mental and real performance matched. Group 3 executed the same number of BBTs but without MI.

MC ability only improved in Group 1. The improvement lasted for at least 24 hours. In all groups, BBT real performance was improved post-training.

External feedback was able to enhance MC capability which might be an approach for improving MI abilities.