Interpreting fMRI data: maps, modules and dimensions

Hans P. Op de Beeck*, Johannes Haushofer‡ and Nancy G. Kanwisher‡
Nature reviews neuroscience, volume 9, february 2008, 123

Neuroimaging research over the past decade has revealed a detailed picture
of the functional organization of the human brain. Here we focus on two fundamental
questions that are raised by the detailed mapping of sensory and cognitive functions and illustrate these questions with findings from the object-vision pathway. First, are functionally specific regions that are located close together best understood as distinct cortical modules or as parts of a larger-scale cortical map? Second, what functional properties define each cortical map or module? We propose a model in which overlapping continuous maps of simple features give rise to discrete modules that are selective for complex stimuli.

Fulltext: http://www.nature.com/nrn/journal/v9/n2/pdf/nrn2252.pdf

Map:
A clustering of neurons with similar functional properties that is characterized by a
gradual progression of preferred stimulus values across the cortical sheet.

Module:
A clustering of neurons with similar functional properties that is characterized by
discrete regions with clear boundaries across which there is no relation in preferred
stimulus values.