Wait and see

Anticipatory behavior is aimed at goals that can be reached in the near future. Underlying this behavior are neurophysiological processes, which realize a setting of brain structures involved in the future perception, informa-tion processing and action. Anticipatory behavior is accompanied by slow brain potentials, which are generated in the Ž. Ž.cerebral cortex. They are known as the readiness potential RP, the contingent negative variation CNV and the Ž.stimulus preceding negativity SPN. The RP reflects the timing of a future voluntary movement. The CNV reflects the preparation of a signaled movement and the simultaneous anticipatory attention for the imperative stimulus. The SPN reflects partly the anticipatory attention for the upcoming stimulus. Although these slow potentials are generated in the cortex, the paper shows that a subcortical input from basal ganglia, and in the case of the RP also from the cerebellum, is a necessary condition for their emergence. Slow cortical potentials are the result of concerted activity in a number of cerebral networks, in which the thalamus forms a crucial node. It is suggested that the reticular nucleus of the thalamus plays a pivotal role in anticipatory attention. 2001 Elsevier Science B.V. All rights reserved