“…54 We propose that one of the important causes for the diminished efficacy is the reduced opportunity for the participants in double-blind RCTs to learn how to make use of the newly grafted DA-rich cells for achieving optimal recovery. 13,54 The results of decades of clinical research 57,58 indicate that the best way to ensure optimal outcomes is to provide clear information about what to do during the recovery process and also to negotiate clear therapeutic goals. It is arguably advantageous, following the grafting of neurons in people with PD, to systematically enhance motivation, goal-directed activities, physical activity levels, and the reinforcement of improvements in functioning if and when they emerge.…”