Presentation

Patti Adank¹, Hannah Wilt¹, Anthony Trotter^1,2, Harold Bekkering³; ¹University College London, London, ²King's College London, London, ³Donders Institute for Brain, Cognition and Behaviour,

Behavioural, neuroimaging, and neurostimulation evidence shows that observing others’ manual and vocal actions evoke a covert imitative response. Observing someone perform an action automatically activates neural substrates associated with executing that action. Such covert, or automatic, imitation is measured behaviourally using the Stimulus Response Compatibility (SRC) task as a difference in response times (or accuracy) between incompatible and compatible trials. Responses slower when performing an action (“say ba”) that is incompatible to an irrelevant distracter (a video of someone saying "da") compared to when the action in the distracter matches the instruction (“say ba” with a “ba” video). Past studies have investigated the neural network supporting automatic imitation of manual actions using functional Magnetic Resonance Imaging (fMRI) [1,2,3]. These studies outline a network linked to “inhibition of imitation”, which is measured as a contrast between neural responses to incompatible and compatible actions. These studies included manual actions only and reported engagement of dorsolateral prefrontal cortex (DLPFC), and temporo-parietal junction (TPJ). No study has thus far explored the neural network associated with inhibiting imitation of vocal actions. It is unclear whether inhibition of automatic imitation engages a neural network in a modality-specific or modality-independent manner. Participants will have their neural responses scanned while they perform an SRC task for vocal (a video-only representation of someone saying “ba” or “da”) or manual stimuli (a video of a hand lifting index or middle finger). We will record their vocal and manual response times as well as eye gaze. We expect that we will uncover the network reported for automatic imitation of manual actions, involving DLPFC and TPJ across both modalities and expect we will be able to detect modality-specific differences, e.g., increased activation in left Inferior Frontal Gyrus and Premotor Cortex for automatic imitation of vocal compared to manual actions [4] and will also explore effector-specific differences per modality in Region of Interest analyses, e.g., finger or articulator-specific analyses in speech and hand areas of Primary Motor Cortex. Due to the COVID-19 pandemic data collection for this study was delayed and we expect to have completed data collection and analysis in summer 2022. References: 1. Darda, K. M. & Ramsey, R. The inhibition of automatic imitation: A meta-analysis and synthesis of fMRI studies. NeuroImage 197, 320–329 (2019). 2. Brass, M., Derrfuss, J. & von Cramon, D. Y. The inhibition of imitative and overlearned responses: a functional double dissociation. Neuropsychologia 43, 89–98 (2005). 3. Spengler, S., von Cramon, D. Y. & Brass, M. Control of shared representations relies on key processes involved in mental state attribution. Human brain mapping 30, 3704–3718 (2009). 4. Molnar-Szakacs, I., Iacoboni, M., Koski, L. & Mazziotta, J. C. Functional segregation within pars opercularis of the inferior frontal gyrus: evidence from fMRI studies of imitation and action observation. Cerebral Cortex 15, 986–994 (2005).

Topic Areas: Multisensory or Sensorimotor Integration, Speech Motor Control