Unmasking unmasked: neural dynamics following stroke

Anatomy is not destiny Recovery from disease involves the interaction of the biological substrate with behavior. Nowhere is this more clearly seen than in the setting of a neurological disease such as stroke, where mind and behavior are directly, though sometimes subtly, affected. During recovery from stroke, a large web of causal chains lead to an improved condition or to continued disability. Recovery starts with the mental and physical process of rehabilitation ther-apy, which alters the physical state of the brain as it teaches new strategies and enhances muscle tone. Subsequently, the altered brain patterns in part determine what further rehabilitative actions the patient is capable of, leading to a vicious or virtuous cycle. Although many aspects of these healing cycles are beyond our control and will likely remain so, there are points at which we can intervene. In order to achieve the greatest rehabili-tative effect, we can choose the timing and type of rehabilitation strategy and pharmacotherapeutic measures that will produce desirable brain changes. The difficulty in connecting brain and behavior is a prominent part of the more general problem of causality in neuroscience. Assigning cause is difficult because of the enormous complexity of this organ. Like the better understood liver or lung, the brain is studied using a variety of technique