Decoding motor imagery from the posterior parietal cortex of a tetraplegic human

Brain imagination to control external devices Studies in monkeys have implicated the brain's posterior parietal cortex in high-level coding of planned and imagined actions. Aflalo et al. implanted two microelectrode arrays in the posterior parietal cortex of a tetraplegic patient (see the Perspective by Pruszynski and Diedrichsen). They asked the patient to imagine various types of limb or eye movements. As predicted, motor imagery involved the same types of neural population activity involved in actual movements, which could potentially be exploited in prosthetic limb control. Science , this issue p. 906 ; see also p. 860