Georgiev, C. | Search bioRxiv

bioRxiv2023

An Open-Access Database of Video Stimuli for Action Observation Research in Neuroimaging Settings: Psychometric Evaluation and Motion Characterization

Video presentation has become ubiquitous in paradigms investigating the neural and behavioral responses to observed actions. In spite of the great interest in uncovering the processing of observed bodily movements and actions in neuroscience and cognitive science, at present, no standardized set of video stimuli for action observation research in neuroimaging settings exists. To facilitate future action observation research, we developed an open-access database of 135 high-definition videos of a male actor performing object-oriented actions. Actions from 3 categories: kinematically natural and goal-intact (Normal), kinematically unnatural and goal-intact (How), or kinematically natural and goal-violating (What), directed towards 15 different objects were filmed from 3 angles. Psychometric evaluation of the database revealed high video recognition accuracy (Mean accuracy = 88.61 %) and substantial inter-rater agreement (Fleiss Kappa = 0.702), establishing excellent validity and reliability. Videos exact timing of motion onset was identified using a custom motion detection frame-differencing procedure. Based on its outcome, the videos were edited to assure that motion begins at the second frame of each video. The videos timing of category recognition was also identified using a novel behavioral up-down staircase procedure. The identified timings can be incorporated in future experimental designs to counteract jittered stimulus onsets, thus vastly improving the sensitivity of neuroimaging experiments. All videos, their psychometric evaluations, and the timing of their frame of category recognition, as well as our custom programs for performing these evaluations on our, or on other similar video databases, are available at the Open Science Framework (https://osf.io/zexc4/).

neuroscience↗

bioRxiv2023

Afferents to Action: Cortical proprioceptive processing assessed with corticokinematic coherence specifically predicts gross motor skills

Voluntary motor control is thought to be predicated on the ability to efficiently integrate and process somatosensory afferent information. However, current approaches in the field of motor control have not factored in objective markers of how the brain actually tracks incoming somatosensory information. Here, we asked whether motor performance relates with such markers obtained with an analysis of the coupling between peripheral kinematics and cortical oscillations during continuous movements, best known as corticokinematic coherence (CKC). Motor performance was evaluated by measuring both gross and fine motor skills using the Box and Blocks Test (BBT) and the Purdue Pegboard Test (PPT), respectively, and with a biomechanics measure of coordination. Sixty-one participants completed the BBT, while equipped with electroencephalography and electromyography, and the PPT. We evaluated CKC, from the signals collected during the BBT, as the coherence between movement rhythmicity and brain activity, and coordination as the cross-correlation between muscle activity. CKC at movements first harmonic was positively associated with BBT scores, and showed a relationship with PPT scores, but only in synergy with BBT scores, where participants with lower PPT score had higher CKC than expected based on their BBT score. Coordination was not associated with motor performance and at most, weakly related to CKC. These findings demonstrate that cortical somatosensory processing in the form of strengthened brain-peripheral coupling is specifically associated with better gross motor skills. CKC might be considered as a valuable addition to classical tests of proprioceptive acuity, with important perspectives for future clinical studies and practice. Significance StatementWhether standing upright, jogging, or in Olympic competition, our nervous system not only sends out motor commands prompting muscles to contract, but also receives incoming information to fine-tune motor actions. Though the machinery involved in sensing mechanical changes is well-described, the neural processing of this information is not, making its relevance to motor function unresolved. We found that the coupling strength between peripheral kinematics and cortical activity was related to motor function and at most, only weakly related to conventional muscle-only assessments. We present novel behavioral relevance of this coupling and its specific relationship to gross motor skill. Our study paves the way for including novel brain-centered approaches to complement classical assessment sensorimotor functions in health and disease.

neuroscience↗