have coordinate types (to divide coordinates between different purposes)

[jdkent]

Coordinates are reported in different papers for different purposes. I think the below provide adequate coverage of the different purposes of coordinates being reported in papers.

Coordinate Type Descriptions

1. contrast

Coordinates that represent peak activations or deactivations derived from a statistical comparison between conditions, groups, or tasks (e.g., Task A > Task B, Patients > Controls). These coordinates mark local maxima from whole-brain voxelwise contrasts and reflect differences in neural activity attributable to an experimental manipulation or group effect.

2. association

Coordinates that represent brain–behavior or brain–variable relationships, where signal/activation varies with a continuous regressor such as symptom severity, reaction time, trial difficulty, age, performance score, etc. These include parametric modulations, correlation analyses, and regression peaks that do not involve a categorical contrast.

3. seed/ROI

Coordinates used to define regions of interest—typically spherical or anatomically centered regions—from which data are extracted or analyzed. This includes seeds for functional connectivity, effective connectivity (e.g., PPI, DCM), structural connectivity (tractography), stimulation targets (TMS/tDCS/DBS), and atlas or parcel node definitions. These coordinates serve primarily as analytic anchors rather than results of contrasts or associations.

4. localization

Coordinates used simply to report the anatomical location of sensors, electrodes, fiducials, intracranial contacts, dipole solutions, source reconstructions, or anatomical landmarks. These coordinates do not represent statistical peaks, seeds, or hypotheses, but serve as metadata describing where a device, measurement, or structural feature is located in standardized space.

5. multivariate

Coordinates representing the center or peak of multivariate pattern analysis results, such as searchlight decoding, classifier-weight maxima, representational similarity mapping (RSM/RSA) clusters, or other algorithms identifying regions with high discriminative information. These coordinates reflect informational content, not univariate activation or connectivity.

6. morphometric feature

Coordinates that denote structural MRI findings such as peaks of cortical thinning, volume loss, shape deformation, or other voxelwise/surface-based morphometric effects. These coordinates localize structural abnormalities or structural associations without referring to task-evoked activations.

7. lesion mapping

Coordinates that represent lesion centers, lesion clusters, or lesion–symptom mapping results (e.g., VLSM, lesion network mapping). These coordinates localize brain injury, stroke, or focal pathology and are used to relate lesion location to behavioral impairments, symptoms, or connectivity profiles.