Reach-To-Grasp Movements: A Multimodal Techniques Study

Abstract

The aim of the present study was to investigate the correlation between corticospinal activity, kinematics, and electromyography (EMG) associated with the execution of precision and whole-hand grasps (WHGs). To this end, motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS), EMG, and 3-D motion capture data have been simultaneously recorded during the planning and the execution of prehensile actions toward either a small or a large object. Differences in the considered measures were expected to distinguish between the two types of grasping actions both in terms of action preparation and execution. The results indicate that the index finger (FDI) and the little finger (ADM) muscles showed different activation patterns during grasping execution, but only the FDI appeared to distinguish between the two types of actions during motor preparation. Kinematics analysis showed that precision grips differed from WHGs in terms of displayed fingers distance when shaping before object’s contact, and in terms of timing and velocity patterns. Moreover, significant correlations suggest a relationship between the muscular activation and the temporal aspects concerned with the index finger’s extension during whole-hand actions. Overall, the present data seem to suggest a crucial role played by index finger as an early “marker” of differential motor preparation for different types of grasps and as a “navigator” in guiding whole-hand prehensile actions. Aside from the novelty of the methodological approach characterizing the present study, the data provide new insights regarding the level of crosstalk among different levels concerned with the neuro-behavioral organization of reach-to-grasp movements.

Concurrent Multimodal Data Acquisition During Brain Scanning is within Reach

“…Thus, the visual behaviour reported here was limited to a general estimation of when the eyes were focused on or near the target object rather than a precise 3D spatial location. Consequently, we were unable to determine whether fixations prior to grasping focused on where the index finger (first digit to touch) or thumb (associated with subsequent object manipulation) was going to make contact (Belardinelli et al, 2016;Betti et al, 2018;Cavina-Pratesi & Hesse, 2013;Voudouris, Smeets, Fiehler, & Brenner, 2018), or else on the centre of target mass, associated with prior knowledge of the task (Voudouris, Broda, & Fiehler, 2019). Therefore, the eye-tracking camera positioning used in these methods is limited.…”

“…In addition, future investigations seeking to explore the involvement of somatosensory suppression associated with goal-directed visually guided movement and grip formation may include pressure sensors on the target objects, in order to increase temporal specificity of the tactile stimulus received, and locate the associated neural response (Voudouris et al, 2019). Moreover, future studies may want to include electromyography alongside the modalities included here, in order to identify a more precise order of the timing of motor signals involved in reach to grasp planning and control (Betti et al, 2018;Gribble et al, 2002;Sburlea & Muller-Putz, 2018).…”

“…To date, a large portion of human brain recordings in visuomotor research have been made in isolation, without motion tracking (Cavina-Pratesi, Goodale, & Culham, 2007;Ehrsson et al, 2000;Gallivan, Cavina-Pratesi, & Culham, 2009;Zaepffel & Brochier, 2012) Culham et al, 2003. When hand movements are recorded during brain scanning, eyetracking is typically absent (Betti, Zani, Guerra, Castiello, & Sartori, 2018;Bradberry, Gentili, & Contreras-Vidal, 2010;De Sanctis, Tarantino, Straulino, Begliomini, & Castiello, 2013;Di Bono et al, 2017;Mateo et al, 2015;Swett, Contreras-Vidal, Birn, & Braun, 2010;Tscherpel et al, 2020) presumably due to the challenges associated with placement of cameras and lighting, as well as the electrical noise produced by cameras during reach-tograsp in an fMRI or MEG scanner. Hence, eye-tracking during brain scanning is mostly obtained during reach-to-grasp tasks that lack ecological validitytypically using virtual reality without tactile completion (Committeri et al, 2004;Limanowski, Kirilina, & Blankenburg, 2017), viewing and 'grasping' images of objects presented on a screen (Park et al, 2014), or else while viewing the target object via a series of mirrors (Frey, Hansen, & Marchal, 2015;W.…”

Look at Me: Early Gaze Engagement Enhances Corticospinal Excitability During Action Observation

“…MEPs were recorded simultaneously from the FDI and ADM muscles of the participant’s right hand. These muscles were chosen because of their differential activation during the observation of PG and WHG (e.g., Betti et al, 2018 ). In particular, ADM is only activated for WHG, whereas FDI is modulated during observation of both types of grasp (e.g., Gangitano et al, 2001 ).…”

The Shape of Water: How Tai Chi and Mental Imagery Effect the Kinematics of a Reach-to-Grasp Movement

“…In this regard, kinematics can offer an indirect measure of muscular patterns, as revealed by a recent study combining kinematic and EMG measures during the execution of reach-to-grasp actions. In particular, Betti et al (2018) showed that a short phase of hand closing on the targetindexed by a late grip aperture -was correlated with a decreased activation of hand muscles (Betti et al, 2018). More in general, combined EMG-kinematic studies associate reaching efficiency with reduced wrist velocity and deceleration (van Vliet and Sheridan, 2007;Wagner et al, 2007), while good accuracy and later closing of the hand are signs of grasping dexterity (Castiello et al, 1992;Becchio et al, 2008a,b).…”