The specific contribution of neuroimaging versus neurophysiological data to understanding cognition

The role of neuroscience for the understanding of cognitive processes is a matter of controversial discussions. While it is widely accepted that neuroscientific data do contribute to theories on cognition in some way, their specific value is most often not explicitly described. One central issue is the validity of the inference from neuroscientific data to underlying cognitive processes, which depends on the characteristic properties of the respective neuroscientific method. In the first part of this review, we discuss the conditions under which data from functional MRI (fMRI), surface EEG, and intracranial EEG recordings may be interpreted with respect to associated cognitive processes. We will show that due to the different signal characteristics in each domain, cognitive processes at different levels can be captured. In the second part, we address the specific contribution made by neuroscientific data to the understanding of cognition. We show that neuroscientific findings may move beyond psychological theories based on purely behavioral data in several respects, which again depend on the imaging modality. Taken together, we suggest that neuroscientific data contribute to the understanding of cognition by adding specific biological constraints and by extending the explanatory potential of psychological theories. (C) 2009 Elsevier B.V. All rights reserved.