Amy L. Parkinsona,b, *, Oleg Korzyukovc, Charles R. Larsonc, Vladimir Litvakd, Donald A. Robina,b
Modulation of effective connectivity during vocalization with perturbed auditory feedback
Research Imaging Institute, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229

The integration of auditory feedback with vocal motor output is important for the control of voice fundamental frequency (F0). We used a pitch-shift paradigm where subjects respond to an alteration, or shift, of voice pitch auditory feedback with a reflexive change in F0. We presented varying magnitudes of pitch shifted auditory feedback to subjects during vocalization and passive listening and measured event related potentials (ERP’s) to the feedback shifts. Shifts were delivered at +100 and +400 cents (200 ms duration). The ERP data were modeled with Dynamic Causal Modeling (DCM) techniques where the effective connectivity between the superior temporal gyrus (STG), inferior frontal gyrus and premotor areas were tested. We compared three main factors; the effect of intrinsic STG connectivity, STG modulation across hemispheres and the specific effect of hemisphere. A Bayesian model selection procedure was used to make inference about model families. Results suggest that both intrinsic STG and left to right STG connections are important in the identification of self-voice error and sensory motor integration. We identified differences in left to right STG connections between 100 cent and 400 cent shift conditions suggesting that self and non-self voice error are processed differently in the left and right hemisphere. These results also highlight the potential of DCM modeling of ERP responses to characterize specific network properties of forward models of voice control.

a.Research Imaging Institute, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
b.Department of Neurology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
c. Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, USA
d.Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, UK
* Corresponding author