A sample unit for holding standing and the areal distributions of 104 similar units. A. Peri-event time histogram (bin size = 30 ms) of an example unit with peak activity during the holding phase. Purple inverted triangle: Target On; pink triangle: Center Hit again. B and C. coronal and vertical view of the areal distribution of related units. CS: Central sulcus, PA: posterior–anterior, DL: dorsal-lateral.