{Reference Type}: Journal Article {Title}: Evidence for planning and motor subtypes of stuttering based on resting state functional connectivity. {Author}: Rowe HP;Tourville JA;Nieto-Castanon A;Garnett EO;Chow HM;Chang SE;Guenther FH; {Journal}: Brain Lang {Volume}: 253 {Issue}: 0 {Year}: 2024 Jun 2 {Factor}: 2.781 {DOI}: 10.1016/j.bandl.2024.105417 {Abstract}: We tested the hypothesis, generated from the Gradient Order Directions Into Velocities of Articulators (GODIVA) model, that adults who stutter (AWS) may comprise subtypes based on differing connectivity within the cortico-basal ganglia planning or motor loop. Resting state functional connectivity from 91 AWS and 79 controls was measured for all GODIVA model connections. Based on a principal components analysis, two connections accounted for most of the connectivity variability in AWS: left thalamus - left posterior inferior frontal sulcus (planning loop component) and left supplementary motor area - left ventral premotor cortex (motor loop component). A k-means clustering algorithm using the two connections revealed three clusters of AWS. Cluster 1 was significantly different from controls in both connections; Cluster 2 was significantly different in only the planning loop; and Cluster 3 was significantly different in only the motor loop. These findings suggest the presence of planning and motor subtypes of stuttering.