What Are We Missing Here? Brain Imaging Evidence for Higher Cognitive Functions in Primary Visual Cortex V1

Functional magnetic resonance imaging (fMRI) and neuron electrophysiology (neurophysiology) are two well-established ways to measure brain activity. Even though the spatial and temporal resolution of these techniques is very different, both measurements show a high level of consistency, i.e., for mapping feature preferences of cortical areas. There are, however, other striking differences between fMRI and neurophysiology, for example, fMRI has good accessibility to higher cognitive functions, a bias to measure synaptic activity, and a good sensitivity to detect feedback-related activity, all of which can shed a new light on the function of well-known brain areas like primary visual cortex, V1. Classically, it is believed that V1 cells are exhaustively characterized by their complex receptive field properties. Contrary to this view, however, fMRI shows that response properties in area V1 are spatially unstable, influenced by contextual information, and depend on internal states. This review will highlight some of the most striking new fMRI findings that show Vi is involved in higher cognitive functions. (C) 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 131-139, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20236