# DIVA Meets EEG: Model Validation Using Formant-Shift Reflex
## 3 Results
### Behavioral and Physiological Data  
During the formant-shift experiment, F1 varied between conditions (F\({}_{(29,2)}\) = 23.052, \(p\) < 0.001), as participants compensated for auditory feedback perturbations (Figure 6A, right panel). The F1 deviations counteracted the perturbational formant-shifts, such that F1 compensations were in the opposite direction to the perturbations (Figure 6A, left panel). The F1 of both types of compensations significantly differed from that of vocalizations elicited during unperturbed feedback (Holm post hoc test, \(p\) < 0.0.5). Figure 5: Simulations of the brain cortical activity associated with the different DIVA maps elicited by auditory feedback perturbations (F1 shifts) during the vocalization of the phoneme /e/. (**A**) Time course of activity of the DIVA cortical maps whose activity varied in response to feedback perturbations. Activities in undisturbed, downshifted, and upshifted conditions are presented. The shaded area represents the N1-P2 interval of the ERP. t: target, s: state, e: error (**B**) Scalp topography and source space representation of the synthetic EEG estimated in the time interval that corresponds to the generation of the N1-P2 complex. (**C**) Synthetic EEG (N1-P2 interval) contrasted across conditions. Figure 6: Acoustic and electrophysiological parameters describing the monitoring of one’s own vocalization. **(A)** Examples of vocal compensations elicited by F1 perturbations in the auditory feedback. In the left panel, an oscillogram representative of the phoneme /mes/ is illustrated. Likewise, the direction of the perturbation is indicated at the top of each chart. The mean F1 values of vocalizations produced in unperturbed acoustic conditions and those of vocal compensations to perturbed auditory feedback are presented in the right panel, along with the corresponding sample distributions. **(B)** Event-related potential (ERP) elicited by actively monitoring the auditory feedback of one’s own vocalizations. In the left panel, the grand average of the ERP elicited by both unperturbed and F1-shifted auditory feedback are presented. The shaded area indicates the N1-P2 complex. Scalp topography of the N1-P2 complex is illustrated in the middle panel. The mean amplitude of the N1-P2 complex elicited by unperturbed and perturbed auditory feedback are presented in the right panel, along with the corresponding sample distribution. **(C)** Current density maps illustrating the brain generators of the N1-P2 complex in the different conditions (unperturbed and perturbated auditory feedback). **(D)** Differences in the cortical activity obtained in response to unperturbed and perturbated auditory feedbacks. The difference between the current density maps elicited by F1 perturbations of equal magnitude and opposite directions is presented in the right panel. **(E)** Cortical sources of the N1-P2 complex elicited in response to F1 perturbations in the auditory feedback of one’s own vocalizations that are predicted by the DIVA model. They are illustrated both areas and voxels for which the activity predicted by the model overlapped that estimated from the real EEG. Statistically significant differences between groups are represented by *. F1 perturbation induced changes in the cortical activity associated with monitoring the sensory feedback of one's own voice, which was reflected in the N1-P2 amplitude of the ERP obtained across conditions (F\({}_{(29,2)}\) = 29.047, \(p\) < 0.001) and the changes in ERP scalp topography (Figure 6B). The N1-P2 amplitude elicited in response to both upward and downward perturbations was higher than that obtained when auditory feedback was unperturbed (Holm post hoc test, \(p\) < 0.001). The N1-P2 amplitude did not differ when F1 was upward and downward perturbed (Holm post hoc test, \(p\) = 0.36). The cortical source of the ERP associated with monitoring of one's own voices were estimated in large portions of the frontal, temporal, and parietal lobes (Figure 6C).