A number of regions in the frontal and parietal cortex show extreme domain generality, with a similar pattern of activity for many different kinds of cognitive demand. We call this multiple-demand or MD cortex.

To define MD regions, activity can be averaged from a diverse set of tasks. Seven tasks were used in:

Fedorenko, E., Duncan, J., & Kanwisher, N. (submitted). Extreme domain-generality in specific regions of frontal and parietal cortex.

[attachment:NiftiVolume.nii.gz The full unthresholded volume can be downloaded in Nifti format from this link].

The units are t-statistics from contrasts that isolate cognitive demand, averaged across the seven tasks. To create a symmetrical volume, data from left and right hemispheres were averaged, then projected back to both hemispheres. The figure below shows the main foci of the multiple demand system when this volume is thresholded at a value of t>1.5.

attachment:MDmedial.png attachment:MDlateral.png

The next figure shows a parcellation into regions of interest (7 of 27 clusters are visible), after thresholding at t>1.5. If a cluster contained multiple peaks that also survived t>2.7, then the larger cluster was subdivided, assigning each voxel to the nearest subregion at the higher threshold.

attachment:ROIfig.png

[attachment:MDROI.nii A volume that assigns unique numerical labels to each of these regions of interest can be downloaded from here.]