Beneath the surface: Interactions of subthreshold gestural systems

Control of articulatory movements is dominated by gestural systems whose activation states are above a threshold. These highly active systems strongly drive activity in spatial fields encoding articulatory targets, thereby governing the kinematics of vocal tract systems. In the presence of these strong forces, gestural systems with below-threshold activation exert weaker, sometimes opposing forces on target fields. These subtle forces can generate consistent subcategorical patterns of phonetic variation conditioned on the co-activation of gestural systems. Depending on the relations between targets of gestural systems and their force distributions, this variation can give rise to different types of long-distance phonological patterns.