DIVA model.

DIVA model parameters
Name	Default Value	Description
αff	0.9	Contribution of feedforward command to total command; feedforward gain
αfb	0.1	Contribution of the feedback command; feedback gain
τMAr	5ms	Transmission delay from motor cortex cell activity to physical movement of articulators
τArS	10ms	Transmission delay from movement of articulators to feedback signals in somatosensory cortex
τArAu	25ms	Transmission delay from movement of articulators to feedback signals in auditory cortex
τPM	5ms	Transmission delay from premotor (speech sound map) to motor cortex
τPS	20ms	Transmission delay from premotor to somatosensory cortex
τPAu	35ms	Transmission delay from premotor to auditory cortex
τSM	5ms	Transmission delay from somatosensory to motor cortex
τAuM	5ms	Transmission delay from auditory to motor cortex

DIVA model equations
Equation	Description
$M(t)=M(0)+{\alpha }_{ff}\underset{0}{\overset{t}{\int }}{\dot{M}}_{ff}(t)g(t)dt+{\alpha }_{fb}\underset{0}{\overset{t}{\int }}{\dot{M}}_{fb}(t)g(t)dt$	Motor cortex position map
Ṁfb(t) = ΔAu(t − τAuM)zAuM + ΔS(t − τSM)zSM	Feedback motor command
Ṁff (t) = P(t)zPM (t) − M(t)	Feedforward motor command
ΔAu(t) = Au(t) −P(t − τPAu)zPAu (t)	Auditory error map activity
ΔS(t) = S(t) − P(t − τPS) zPS (t)	Somatosensory error map activity
Au(t), S(t)	Auditory and somatosensory state activity
zAuM, zSM	Synaptic weights that transform auditory and somatosensory error into corrective motor velocities for a speech sound
zPM	Synaptic weights encoding feedforward commands for a speech sound
zPAu, zPS	Synaptic weights encoding auditory and somatosensory expectation for a speech sound
$P(t)=\begin{array}{cc}1& \text{If sound is being produced or perceived}\\ 0& \text{otherwise}\end{array}$	Speech sound map activity
g(t)	Go signal

α_ff and α_fb were varied systematically in the simulation series. Further details concerning the parameters and equations can be found in Guenther et al. (2006).