scholarly journals Motor Recruitment during Action Observation: Effect of Interindividual Differences in Action Strategy

2020 ◽  
Vol 30 (7) ◽  
pp. 3910-3920 ◽  
Author(s):  
P M Hilt ◽  
P Cardellicchio ◽  
E Dolfini ◽  
T Pozzo ◽  
L Fadiga ◽  
...  
Keyword(s):  
Visual Processing ◽  
Action Observation ◽  
Negative Relationship ◽  
Single Subject ◽  
Action Strategy ◽  
Sensorimotor Activity ◽  
Motor Excitability ◽  
Search And Selection ◽  
Motor Recruitment ◽  
Individual Motor

Abstract Visual processing of other’s actions is supported by sensorimotor brain activations. Access to sensorimotor representations may, in principle, provide the top-down signal required to bias search and selection of critical visual features. For this to happen, it is necessary that a stable one-to-one mapping exists between observed kinematics and underlying motor commands. However, due to the inherent redundancy of the human musculoskeletal system, this is hardly the case for multijoint actions where everyone has his own moving style (individual motor signature—IMS). Here, we investigated the influence of subject’s IMS on subjects’ motor excitability during the observation of an actor achieving the same goal by adopting two different IMSs. Despite a clear dissociation in kinematic and electromyographic patterns between the two actions, we found no group-level modulation of corticospinal excitability (CSE) in observers. Rather, we found a negative relationship between CSE and actor-observer IMS distance, already at the single-subject level. Thus, sensorimotor activity during action observation does not slavishly replicate the motor plan implemented by the actor, but rather reflects the distance between what is canonical according to one’s own motor template and the observed movements performed by other individuals.

scholarly journals Self-selected conscious strategies do not modulate motor cortical output during action observation

2015 ◽  
Vol 114 (4) ◽  
pp. 2278-2284 ◽  
Author(s):  
Katherine R. Naish ◽  
Sukhvinder S. Obhi
Keyword(s):  
Exploratory Study ◽  
Motor Evoked Potentials ◽  
Action Observation ◽  
Abductor Muscle ◽  
Fixation Cross ◽  
Initial Block ◽  
Motor Excitability ◽  
Human Motor ◽  
Conscious Control

The human motor system is active not only when actions are performed but also when they are observed. Experimenters often manipulate aspects of the action or context to examine factors that influence this “mirror” response. However, little is known about the role of the observer's own top-down intentions and motivation. In this exploratory study, we investigated whether observers are able to exert conscious control over their mirror response, when they are explicitly instructed to either increase or decrease mirroring. Transcranial magnetic stimulation (TMS) was used to elicit motor-evoked potentials (MEPs) in a thumb abductor muscle as participants ( n = 13) watched a video of a hand squeezing a rubber ball. The size of these MEPs, relative to the size of MEPs elicited during fixation cross observation, was taken as an index of mirroring. In an initial block of trials, participants were instructed to merely observe the actions presented. After the first block, the concept of mirroring was explained to the participants, and in the second and third blocks participants were instructed to either increase or decrease their mirror response. We did not instruct them about how to achieve this increase or decrease. Our results showed no difference in either facilitation or absolute motor excitability (i.e., nonnormalized MEP size) between the three blocks, indicating that individuals do not seem to be able to exert control over motor excitability during action observation, at least in the absence of a specific and maintained strategy.

scholarly journals Relationship between cardiac cycle and the timing of actions during action execution and observation

2019 ◽  
Author(s):  
E. R. Palser ◽  
J. Glass ◽  
A. Fotopoulou ◽  
J. M. Kilner
Keyword(s):  
Reaction Time ◽  
Cardiac Cycle ◽  
Healthy Adult ◽  
Action Observation ◽  
Single Subject ◽  
Interpersonal Coordination ◽  
Action Execution ◽  
Sequence Of Movements

AbstractPrevious research suggests that there may be a relationship between the timing of motor events and phases of the cardiac cycle. However, this relationship has thus far only been researched using simple isolated movements such as key-presses in reaction-time tasks and only in a single subject acting alone. Other research has shown both movement and cardiac coordination among interacting individuals. Here, we investigated how the cardiac cycle relates to ongoing self-paced movements in both action execution and observation using a novel dyadic paradigm. We recorded electrocardiography (ECG) in 26 healthy adult subjects who formed 19 dyads (7 comprised of two subjects and 12 subjects paired with an experimenter). Each dyad contained an action executioner and observer as they performed a self-paced sequence of movements. We demonstrated that heartbeats are timed to movements during both action execution and observation. Specifically, movements were less likely to culminate synchronously with the heartbeat, around the time of the R-peak of the ECG. The same pattern was observed for action observation, with the observers’ heartbeats occurring off-phase with movement culmination. These findings demonstrate that there is coordination between an action executioner’s cardiac cycle and the timing of their movements, and that the same relationship is mirrored in an observer. This suggests that previous findings of interpersonal coordination may be caused by the mirroring of a phasic relationship between movement and the heart.

scholarly journals Cortical regions involved in the observation of bimanual actions

2012 ◽  
Vol 108 (9) ◽  
pp. 2594-2611 ◽  
Author(s):  
Marcus H. Heitger ◽  
Marc J.-M. Macé ◽  
Jan Jastorff ◽  
Stephan P. Swinnen ◽  
Guy A. Orban
Keyword(s):  
Parietal Cortex ◽  
Visual Processing ◽  
Visual Motion ◽  
Action Observation ◽  
Premotor Cortex ◽  
Region Of Interest ◽  
Visual Signals ◽  
Activation Patterns ◽  
Action Observation Network ◽  
Bimanual Actions

Although we are beginning to understand how observed actions performed by conspecifics with a single hand are processed and how bimanual actions are controlled by the motor system, we know very little about the processing of observed bimanual actions. We used fMRI to compare the observation of bimanual manipulative actions with their unimanual components, relative to visual control conditions equalized for visual motion. Bimanual action observation did not activate any region specialized for processing visual signals related to this more elaborated action. On the contrary, observation of bimanual and unimanual actions activated similar occipito-temporal, parietal and premotor networks. However, whole-brain as well as region of interest (ROI) analyses revealed that this network functions differently under bimanual and unimanual conditions. Indeed, in bimanual conditions, activity in the network was overall more bilateral, especially in parietal cortex. In addition, ROI analyses indicated bilateral parietal activation patterns across hand conditions distinctly different from those at other levels of the action-observation network. These activation patterns suggest that while occipito-temporal and premotor levels are involved with processing the kinematics of the observed actions, the parietal cortex is more involved in the processing of static, postural aspects of the observed action. This study adds bimanual cooperation to the growing list of distinctions between parietal and premotor cortex regarding factors affecting visual processing of observed actions.

scholarly journals Multiband acceleration can provide moderate improvements in single-subject voxel-wise statistics in block-design task-based fMRI

2019 ◽  
Author(s):  
Ritu Bhandari ◽  
Valeria Gazzola ◽  
Christian Keysers
Keyword(s):  
Action Observation ◽  
Block Design ◽  
Alternative Methods ◽  
Medium Effect ◽  
Single Subject ◽  
Group Level ◽  
Action Observation Network ◽  
Observation Network ◽  
Single Subjects ◽  
The Impact

AbstractMultiband (MB) acceleration of functional magnetic resonance imaging has become more widely available to neuroscientists. Here we compare MB factors of 1, 2 and 4 while participants view complex hand actions vs. simpler hand movements to localize the action observation network. While in a previous study, we show that MB4 shows moderate improvements in the group-level statistics, here we explore the impact it has on single subject statistics. We find that MB4 provides an increase in p values at the first level that is of medium effect size compared to MB1, providing moderate evidence across a number of voxels that MB4 indeed improves single subject statistics. This effect was localized mostly within regions that belong to the action observation network. In parallel, we find that Cohen’s d at the single subject level actually decreases using MB4 compared to MB1. Intriguingly, we find that subsampling MB4 sequences, by only considering every fourth acquired volume, also leads to increased Cohen’s d values, suggesting that the FAST algorithm we used to correct for temporal auto-correlation may over-penalize sequences with higher temporal autocorrelation, thereby underestimating the potential gains in single subject statistics offered by MB acceleration, and alternative methods should be explored. In summary, considering the moderate gains in statistical values observed both at the group level in our previous study and at the single subject level in this study, we believe that MB technology is now ripe for neuroscientists to start using MB4 acceleration for their studies, be it to accurately map activity in single subjects of interest (e.g. for presurgical planning or to explore rare patients) or for the purpose of group studies.

scholarly journals The Effect of Baseline on Toddler Event-Related Mu-Rhythm Modulation

2021 ◽  
Vol 11 (9) ◽  
pp. 1159
Author(s):  
Caterina Piazza ◽  
Eleonora Visintin ◽  
Gianluigi Reni ◽  
Rosario Montirosso
Keyword(s):  
Cognitive Processes ◽  
Action Observation ◽  
Baseline Condition ◽  
Single Subject ◽  
Mu Rhythm ◽  
Action Execution ◽  
Subject Analysis ◽  
Different Types ◽  
Pediatric Populations ◽  
Rhythm Activity

Event-related mu-rhythm activity has become a common tool for the investigation of different socio-cognitive processes in pediatric populations. The estimation of the mu-rhythm desynchronization/synchronization (mu-ERD/ERS) in a specific task is usually computed in relation to a baseline condition. In the present study, we investigated the effect that different types of baseline might have on toddler mu-ERD/ERS related to an action observation (AO) and action execution (AE) task. Specifically, we compared mu-ERD/ERS values computed using as a baseline: (1) the observation of a static image (BL1) and (2) a period of stillness (BL2). Our results showed that the majority of the subjects suppressed the mu-rhythm in response to the task and presented a greater mu-ERD for one of the two baselines. In some cases, one of the two baselines was not even able to produce a significant mu-ERD, and the preferred baseline varied among subjects even if most of them were more sensitive to the BL1, thus suggesting that this could be a good baseline to elicit mu-rhythm modulations in toddlers. These results recommended some considerations for the design and analysis of mu-rhythm studies involving pediatric subjects: in particular, the importance of verifying the mu-rhythm activity during baseline, the relevance of single-subject analysis, the possibility of including more than one baseline condition, and caution in the choice of the baseline and in the interpretation of the results of studies investigating mu-rhythm activity in pediatric populations.

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