A framework for studying the neural basis of attention.

There is a high degree of consensus between the contributors to this volume on the neural correlates of attention. This agreement relates both to the implicit framework the authors apply to their studies of attention and also to the brain regions that are implicated. In this epilogue I will attempt to make explicit the framework that is used and will explore the assumptions that underlie the rules used for identifying the sites of attentional modulation and the sources of the modulatory signals. These assumptions have proved very useful, but most still require further investigation. The distinction between bottom-up and top-down processes is a key components of the framework, but is also a potential source of confusion. It seems that bottom-up processing, in the psychological sense of not being under voluntary control, can involve top-down processes in the physiological sense of involving the feedback of neural signals.