The brain and its resting state activity--experimental and methodological implications.

Despite all the recent progress in neuroscience, we still do not understand the basic principles according to which the brain functions. This may be due, at least in part, to our lack of knowledge how the brain's intrinsic activity, the brain's input, impacts stimulus-induced changes in the brain. We here discuss the neuronal, experimental and methodological relevance of the brain's resting state activity for future studies. Furthermore, we make several suggestions how to best define and include the brain's resting state into our experimental designs. We conclude that experimental consideration of the brain's resting state has major implications for setting up experimental designs and methodological strategies. This may also shed new light on some hitherto unresolved questions like the neuroscientific mechanisms underlying consciousness and psychiatric disorders.