Abstract: In the recent years there has been increased interest in augmentative technologies that extend the physical and cognitive abilities of able-bodied individuals. Supernumerary robotic fingers, such as the ‘Third Thumb’ are an example of such technology, designed to allow the user to single-handedly perform normally bimanual tasks. However, these new devices introduce various theoretical and practical challenges: (i) what resources could one’s brain employ to control a body part that has never been there before? (ii) what are the risks and benefits of modulating one’s body representation in order to support and enhance supernumerary robotic fingers usage? Here, using human somatosensory cortex as a model, we investigate neural correlates of hand augmentation. We train healthy able-bodied participants to use a supernumerary robotic finger over the course of five days. During the training participants have to complete a set of normally bimanual tasks from daily life using only the augmented (right) hand. A separate control group wears the robotic finger for the same duration of time but without using it. We use pre- to post- comparison measures to assess the outcomes of the training and see whether hand augmentation affects the representation of body in the brain. We track neuronal changes in the somatotopic hand representation using 3T fMRI (focusing on representational similarity analysis and functional connectivity) and a set of well-defined behavioural tasks (e.g. force enslavement, motor confusion). We further evaluate the level of embodiment of the supernumerary robotic finger using questionnaires. By studying the neural correlates of hand augmentation, we hope to probe the boundaries of brain plasticity and provide the community with a brand-new model for examining the adult brain’s ability to dynamically update body representations based on new experiences.
Title of my talk: Neural correlates of hand augmentation – brain plasticity following intensive usage of a robotic ‘Third Thumb’