Early Visual Cortex Atlas (V1-V5, cytoarchitectonic)

A convenience loader that extracts the early visual areas from the Julich-Brain cytoarchitectonic atlas and relabels them as V1-V5 per hemisphere. This provides a compact, probabilistically-derived early-visual parcellation in MNI volume space without the surrounding whole-brain regions.

Usage

get_visual_atlas(
  outspace = NULL,
  smooth = FALSE,
  resolution = NULL,
  fsl_dir = Sys.getenv("FSLDIR"),
  download = TRUE
)

Arguments

outspace: Optional NeuroSpace object to resample the atlas into.
smooth: Logical. Whether to smooth parcel boundaries when resampling.
resolution: Optional Julich-Brain resolution (e.g. "1mm" or "2mm"); passed to get_julich_brain_atlas().
fsl_dir: FSL installation directory. Defaults to Sys.getenv("FSLDIR"); when empty and download = TRUE the Julich-Brain FSL cache is downloaded.
download: Logical. Download the Julich-Brain FSL cache when fsl_dir is unset.

Value

A list with classes c("visual", "volatlas", "atlas") containing the V1-V5 regions per hemisphere.

Details

The source regions are the Julich-Brain maximum-probability labels GM Visual cortex V1 BA17, V2 BA18, V3V, V4, and V5 (left/right), loaded via get_julich_brain_atlas(). Note that the Julich atlas defines only the ventral subdivision of V3 (V3V) and a single V4/V5 region per hemisphere.

For the topographic surface atlas with dorsal/ventral subdivisions and hV4, see get_wang_atlas; for a volumetric functional atlas, see get_visfatlas.

References

Amunts, K., Mohlberg, H., Bludau, S., & Zilles, K. (2020). Julich-Brain: A 3D probabilistic atlas of the human brain's cytoarchitecture. Science, 369(6506), 988-992. doi:10.1126/science.abb4588

Examples

if (FALSE) { # \dontrun{
v <- get_visual_atlas()
v$labels
get_roi(v, label = "V1", hemi = "left")
} # }