Sensorimotor Interactions Research Articles

The Role of Embodiment in Learning Representations: Discovering Space Topology via Sensory-Motor Prediction

This paper explores the crucial role of embodiment in learning representations for space topology in robotics. Embodiment, the ability of an agent to interact with its environment and receive sensory feedback, is fundamental to developing accurate and efficient representations. In this work, we investigate this by applying an action-conditional prediction algorithm to data collected from a simulated environment, aiming to learn the topology of the environment through sequences of random interactions. Using a simple mobile-robot-like scenario, by leveraging sensory-motor interactions we demonstrate how the agent can discover the topology of its environment. Our results demonstrate the importance of embodiment in the development of representations and potential applicability in robotic tasks, and a simple but effective method of integrating actions into a learning loop. We suggest that building abstract representations through the use of action-conditional prediction is a step towards unification of the representations used in robotics.

Pleasantness makes a good time: musical consonance shapes interpersonal synchronization in dyadic joint action.

Music making is a process by which humans across cultures come together to create patterns of sounds that are aesthetically pleasing. What remains unclear is how this aesthetic outcome affects the sensorimotor interaction between participants. Here we approach this question using an interpersonal sensorimotor synchronization paradigm to test whether the quality of a jointly created chord (consonant vs. dissonant) affects movement coordination. We recruited non-musician participants in dyads to perform a dyadic synchronization-continuation task (dSCT): on each trial, participants first synchronized their movements to a metronome (synchronization phase) and then continued tapping together at the same tempo without the metronome (continuation phase). Each tap yielded a note and participants heard both their own and that of their partner, thus creating a chord that was varied to be either consonant (Perf5 or Maj6) or dissonant (Min2 or Maj2). For each trial, participants also rated the pleasure they felt in creating the sounds together. Additionally, they completed questionnaires about social closeness to the other participant, musical reward sensitivity and musical training. Results showed that participants' taps were closer in time when they jointly created consonant (high pleasure) vs. dissonant (low pleasure) chords, and that pleasure experienced by the dyad in each trial predicted interpersonal synchronization. However, consonance did not affect individual synchronization with the metronome or individual tapping when the metronome was discontinued. The effect of consonance on synchronization was greater in dyads who reported feeling less close prior to the task. Together, these results highlight the role of consonance in shaping the temporal coordination of our actions with others. More broadly, this work shows that the aesthetic outcome of what we create together affects joint behaviors.

Operation of spinal sensorimotor circuits controlling phase durations during tied-belt and split-belt locomotion after a lateral thoracic hemisection.

Locomotion is controlled by spinal circuits that interact with supraspinal drives and sensory feedback from the limbs. These sensorimotor interactions are disrupted following spinal cord injury. The thoracic lateral hemisection represents an experimental model of an incomplete spinal cord injury, where connections between the brain and spinal cord are abolished on one side of the cord. To investigate the effects of such an injury on the operation of the spinal locomotor network, we used our computational model of cat locomotion recently published in eLife (Rybak et al., 2024) to investigate and predict changes in cycle and phase durations following a thoracic lateral hemisection during treadmill locomotion in tied-belt (equal left-right speeds) and split-belt (unequal left-right speeds) conditions. In our simulations, the "hemisection" was always applied to the right side. Based on our model, we hypothesized that following hemisection, the contralesional ("intact", left) side of the spinal network is mostly controlled by supraspinal drives, whereas the ipsilesional ("hemisected", right) side is mostly controlled by somatosensory feedback. We then compared the simulated results with those obtained during experiments in adult cats before and after a mid-thoracic lateral hemisection on the right side in the same locomotor conditions. Our experimental results confirmed many effects of hemisection on cat locomotion predicted by our simulations. We show that having the ipsilesional hindlimb step on the slow belt, but not the fast belt, during split-belt locomotion substantially reduces the effects of lateral hemisection. The model provides explanations for changes in temporal characteristics of hindlimb locomotion following hemisection based on altered interactions between spinal circuits, supraspinal drives, and somatosensory feedback.

Predicting social experience from dyadic interaction dynamics: the BallGame, a novel paradigm to study social engagement

Theories of embodied cognition suggest that a shared environment and ongoing sensorimotor interaction are central for interpersonal learning and engagement. To investigate the embodied, distributed and hence dynamically unfolding nature of social cognitive capacities, we present a novel laboratory-based coordination task: the BallGame. Our paradigm requires continuous sensing and acting between two players who jointly steer a virtual ball around obstacles towards as many targets as possible. By analysing highly resolved measures of movement coordination and gaming behaviour, game-concurrent experience ratings, semi-structured interviews, and personality questionnaires, we reveal contributions from different levels of observation on social experience. In particular, successful coordination (number of targets collected) and intermittent periods of high versus low movement coordination (variability of relation) emerged as prominent predictors of social experience. Importantly, having the same (but incomplete) view on the game environment strengthened interpersonal coordination, whereas complementary views enhanced engagement and tended to generate more complex interactive behaviour. Overall, we find evidence for a critical balance between similarity and synchrony on the one hand, and variability and difference on the other, for successful engagement in social interactions. Finally, following participant reports, we highlight how interpersonal experience emerges from specific histories of coordination that are closely related to the interaction context in both space and time.

Metacognition bridges experiences and beliefs in sense of agency

Cognitive scientists differentiate the “minimal self” – subjective experiences of agency and ownership in our sensorimotor interactions with the world – from declarative beliefs about the self that are sustained over time. However, it remains an open question how individual sensory experiences of agency are integrated into the belief ofbeing an agent.We administered a sensorimotor task to measure subjects’ (n = 195) propensity to classify stimuli as self-caused and metacognitive monitoring of such judgements, and we compared these behavioral metrics to declarative beliefs about their agency. Subjects who were less sensitive to control cues also reported more negative agency beliefs, though positive beliefs were not clearly correlated with any sensorimotor measure. Importantly, this relationship between first-order sensitivity and declarative beliefs essentially disappears when controlling for metacognitive sensitivity. Results suggest agency beliefs are not related directly to the propensity to make positive agency judgements but are connected through introspective access.

Perceptual coupling in human dyads: Kinematics does not affect interpersonal synchronization

The minimal, essential condition for individuals to interact is that they exchange information via at least one sensory channel. Once informational coupling is established, it enables basic forms of coordinated behavior to spontaneously emerge from the interaction. Our previous study revealed different coordination dynamics in dyads engaged in a joint finger-tapping task based on visual versus auditory coupling. This observation led us to propose the ‘modality-dependent hypothesis', which posits that coordination dynamics are influenced by the sensory modality mediating informational coupling. However, recognizing that different modalities have inherent differences in accessing spatiotemporal features of perceived movement, we formulated the alternative ‘kinematic hypothesis'. This hypothesis posits that differences in dynamics would vanish given equivalent kinematic information across modalities. The study involved forty (N = 40) participants, grouped into twenty (N = 20) dyads, who engaged in a joint finger-tapping task. This task was conducted under varying conditions of visual and auditory coupling, with manipulations in the access to kinematic information, categorized as discrete and continuous. Contrary to our initial predictions, the results strongly supported the ‘modality-dependent hypothesis'. We observed that visual and auditory coupling consistently yielded distinct attractor dynamics, regardless of the access to kinematic information. Furthermore, all conditions of auditory coupling resulted in higher levels of synchronization than their visual counterparts. These findings suggest that the differences in interpersonal synchronization are predominantly influenced by the sensory modality, rather than the continuity of kinematic information. Our study highlights the significance of sensorimotor interactions in interpersonal synchronization and addresses the potential of sonification strategies in supporting motor training and rehabilitation.

Examining behavioral settings and affordative space for the case of autism spectrum conditions in embodied cognition

ABSTRACT The aim of the paper is to deepen into a theoretical account on the role of behavioral settings and relational affordative space and how this perspective can be used to reconceptualize various human cognitive developmental trajectories and conditions. In the course of this theoretical work, we want to contribute in rethinking developmental trajectories based on the role of behavioral settings and relational affordances from an embodied perspective. Behavioral settings emerge from joint actions in conjunction with the affordances available. These affordances will have multiple levels and kinds of meanings for the organism which is why we need to distinguish between the general affordances for a form of life and the particular affordances for particular agents that are generated through sensorimotor interactions. We propose to apply this theoretical frame in different developmental conditions, taking as a leading example the Autistic Spectrum, extending it to other lived experiences of other groups marginalized by “normative behavioral settings” – and the ensuing ethical concerns.

Exploring virtual reality object perception following sensory-motor interactions with different visuo-haptic collider properties

Interacting with the environment often requires the integration of visual and haptic information. Notably, perceiving external objects depends on how our brain binds sensory inputs into a unitary experience. The feedback provided by objects when we interact (through our movements) with them might then influence our perception. In VR, the interaction with an object can be dissociated by the size of the object itself by means of ‘colliders’ (interactive spaces surrounding the objects). The present study investigates possible after-effects in size discrimination for virtual objects after exposure to a prolonged interaction characterized by visual and haptic incongruencies. A total of 96 participants participated in this virtual reality study. Participants were distributed into four groups, in which they were required to perform a size discrimination task between two cubes before and after 15 min of a visuomotor task involving the interaction with the same virtual cubes. Each group interacted with a different cube where the visual (normal vs. small collider) and the virtual cube's haptic (vibration vs. no vibration) features were manipulated. The quality of interaction (number of touches and trials performed) was used as a dependent variable to investigate the performance in the visuomotor task. To measure bias in size perception, we compared changes in point of subjective equality (PSE) before and after the task in the four groups. The results showed that a small visual collider decreased manipulation performance, regardless of the presence or not of the haptic signal. However, change in PSE was found only in the group exposed to the small visual collider with haptic feedback, leading to increased perception of the cube size. This after-effect was absent in the only visual incongruency condition, suggesting that haptic information and multisensory integration played a crucial role in inducing perceptual changes. The results are discussed considering the recent findings in visual-haptic integration during multisensory information processing in real and virtual environments.

Multiple processes of vocal sensory-motor interaction in primate auditory cortex

Sensory-motor interactions in the auditory system play an important role in vocal self-monitoring and control. These result from top-down corollary discharges, relaying predictions about vocal timing and acoustics. Recent evidence suggests such signals may be two distinct processes, one suppressing neural activity during vocalization and another enhancing sensitivity to sensory feedback, rather than a single mechanism. Single-neuron recordings have been unable to disambiguate due to overlap of motor signals with sensory inputs. Here, we sought to disentangle these processes in marmoset auditory cortex during production of multi-phrased ‘twitter’ vocalizations. Temporal responses revealed two timescales of vocal suppression: temporally-precise phasic suppression during phrases and sustained tonic suppression. Both components were present within individual neurons, however, phasic suppression presented broadly regardless of frequency tuning (gating), while tonic was selective for vocal frequencies and feedback (prediction). This suggests that auditory cortex is modulated by concurrent corollary discharges during vocalization, with different computational mechanisms.

Negative emotions disrupt intentional synchronization during group sensorimotor interaction.

Emotions play a fundamental role in human interactions and trigger responses in physiological, psychological, and behavioral modalities. Interpersonal coordination often entails attunement between individuals in various modalities. Previous research has elucidated the mechanisms of interpersonal synchronization and the emotions aroused by joint action: cardiac activity aligns in disputing marital couples, spectators share enjoyment in observing live dance performances, and joint finger-tapping evokes positive emotions. However, little is known about the impact of emotions on intentional interpersonal synchronization. To address this problem, we conducted an experiment in 2022 asking 60 participants to engage in a three-way finger-tapping synchronization task. We systematically induced emotional states (positive, neutral, and negative) with social comparison feedback using success-failure manipulations. An analysis of behavior synchronization using the Kuramoto order parameter revealed that negative emotion induction significantly diminished time spent in synchrony compared to positive induction. Moreover, the results exposed incremental struggles in attaining higher levels of synchronization (Q2-Q3) after the induction of negative emotions. These outcomes further substantiate the necessity of integrating the indices of agents' emotions into interpersonal synchronization and coordination models. We discuss the implications of this work for research on interpersonal emotion in joint action and applied outcomes in emotion-aware technologies and interventions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Submovement interpersonal coupling is associated to audio-motor coordination performance

Acting in concert with others, a key aspect of our social life, requires behavioral coordination between persons on multiple timescales. When zooming in on the kinematic properties of movements, it appears that small speed fluctuations, called submovements, are embedded within otherwise smooth end-point trajectories. Submovements, by occurring at a faster timescale than that of movements, offer a novel window upon the functional relationship between distinct motor timescales. In this regard, it has previously been shown that when partners visually synchronize their movements, they also coordinate the timing of their submovement by following an alternated pattern. However, it remains unclear whether the mechanisms behind submovement coordination are domain-general or specific to the visual modality, and whether they have relevance for interpersonal coordination also at the scale of whole movements. In a series of solo and dyadic tasks, we show that submovements are also present and coordinated across partners when sensorimotor interactions are mediated by auditory feedback only. Importantly, the accuracy of task-instructed interpersonal coordination at the movement level correlates with the strength of submovement coordination. These results demonstrate that submovement coordination is a potentially fundamental mechanism that participates in interpersonal motor coordination regardless of the sensory domain mediating the interaction.

Spatial tactile localization depends on sensorimotor binding: preliminary evidence from virtual reality.

Our brain continuously maps our body in space. It has been suggested that at least two main frames of reference are used to process somatosensory stimuli presented on our own body: the anatomical frame of reference (based on the somatotopic representation of our body in the somatosensory cortex) and the spatial frame of reference (where body parts are mapped in external space). Interestingly, a mismatch between somatotopic and spatial information significantly affects the processing of bodily information, as demonstrated by the "crossing hand" effect. However, it is not clear if this impairment occurs not only when the conflict between these frames of reference is determined by a static change in the body position (e.g., by crossing the hands) but also when new associations between motor and sensory responses are artificially created (e.g., by presenting feedback stimuli on a side of the body that is not involved in the movement). In the present study, 16 participants performed a temporal order judgment task before and after a congruent or incongruent visual-tactile-motor- task in virtual reality. During the VR task, participants had to move a cube using a virtual stick. In the congruent condition, the haptic feedback during the interaction with the cube was provided on the right hand (the one used to control the stick). In the incongruent condition, the haptic feedback was provided to the contralateral hand, simulating a sort of 'active' crossed feedback during the interaction. Using a psychophysical approach, the point of subjective equality (or PSE, i.e., the probability of responding left or right to the first stimulus in the sequence in 50% of the cases) and the JND (accuracy) were calculated for both conditions, before and after the VR-task. After the VR task, compared to the baseline condition, the PSE shifted toward the hand that received the haptic feedback during the interaction (toward the right hand for the congruent condition and toward the left hand for the incongruent condition). This study demonstrated the possibility of inducing spatial biases in the processing of bodily information by modulating the sensory-motor interaction between stimuli in virtual environments (while keeping constant the actual position of the body in space).

Mechanisms of skillful interaction: sensorimotor enactivism & mechanistic explanation

ABSTRACT The mechanistic model depicts scientific explanations as involving the discovery of multi-level, organized components that constitute a target phenomenon. Meanwhile, sensorimotor enactivism purports to offer a scientifically informed account of perceptual experience as a skill-laden interactive relationship, constitutively involving both perceiver and world, rather than as an agent-bound representation of the world. Insofar as sensorimotor enactivism identifies an empirically tractable phenomenon – skillful agent-world interaction – and mechanistic explanation establishes the subpersonal components of this phenomenon, the two approaches allow for a fruitful division of labor in investigating perceptual experience. On closer inspection, however, two challenges arise. First, the “representation challenge” arises because promising attempts to set out implementational details of our sensorimotor interaction with the world implicate cognitive representations, creating tension with sensorimotor enactivism’s nonrepresentational commitments. Second, the “reconstitution challenge” arises when mechanistic explanation not only uncovers the components of some established phenomenon but plays a role in “reconstituting” this phenomenon. This means that, through investigating mechanisms, perceptual experience may be reconceived such that its constituents are wholly organism-bound. We explore both challenges to the compatibility of mechanism and sensorimotor enactivism and examine possible solutions. The result is a clearer understanding of the tensions and opportunities for learning between the frameworks.

3D printed porous membrane integrated devices to study the chemoattractant induced behavioural response of aquatic organisms.

Biological models with genetic similarities to humans are used for exploratory research to develop behavioral screening tools and understand sensory-motor interactions. Their small, often mm-sized appearance raises challenges in the straightforward quantification of their subtle behavioral responses and calls for new, customisable research tools. 3D printing provides an attractive approach for the manufacture of custom designs at low cost; however, challenges remain in the integration of functional materials like porous membranes. Nanoporous membranes have been integrated with resin exchange using purpose-designed resins by digital light projection 3D printing to yield functionally integrated devices using a simple, economical and semi-automated process. Here, the impact of the layer thickness and layer number on the porous properties - parameters unique for 3D printing - are investigated, showing decreases in mean pore diameter and porosity with increasing layer height and layer number. From the same resin formulation, materials with average pore size between 200 and 600 nm and porosity between 45% and 61% were printed. Membrane-integrated devices were used to study the chemoattractant induced behavioural response of zebrafish embryos and planarians, both demonstrating a predominant behavioral response towards the chemoattractant, spending >85% of experiment time in the attractant side of the observation chamber. The presented 3D printing method can be used for printing custom designed membrane-integrated devices using affordable 3D printers and enable fine-tuning of porous properties through adjustment of layer height and number. This accessible approach is expected to be adopted for applications including behavioural studies, early-stage pre-clinical drug discovery and (environmental) toxicology.

Evaluation of EMG patterns in children during assisted walking in the exoskeleton.

While exoskeleton technology is becoming more and more common for gait rehabilitation in children with neurological disorders, evaluation of gait performance still faces challenges and concerns. The reasoning behind evaluating the spinal locomotor output is that, while exoskeleton's guidance forces create the desired walking kinematics, they also affect sensorimotor interactions, which may lead to an abnormal spatiotemporal integration of activity in particular spinal segments and the risk of abnormalities in gait recovery. Therefore, traditional indicators based on kinematic or kinetic characteristics for optimizing exoskeleton controllers for gait rehabilitation may be supplemented by performance measures associated with the neural control mechanisms. The purpose of this study on a sample of children was to determine the basic features of lower limb muscle activity and to implement a method for assessing the neuromechanics of spinal locomotor output during exoskeleton-assisted gait. To this end, we assessed the effects of a robotic exoskeleton (ExoAtlet Bambini) on gait performance, by recording electromyographic activity of leg muscles and analyzing the corresponding spinal motor pool output. A slower walking setting (about 0.2 m/s) was chosen on the exoskeleton. The results showed that, even with slower walking, the level of muscle activation was roughly comparable during exoskeleton-assisted gait and normal walking. This suggests that, despite full assistance for leg movements, the child's locomotor controllers can interpret step-related afferent information promoting essential activity in leg muscles. This is most likely explained by the active nature of stepping in the exoskeleton (the child was not fully relaxed, experienced full foot loading and needed to maintain the upper trunk posture). In terms of the general muscle activity patterns, we identified notable variations for the proximal leg muscles, coactivation of the lumbar and sacral motor pools, and weak propulsion from the distal extensors at push-off. These changes led to the lack of characteristic lumbosacral oscillations of the center of motoneuron activity, normally associated with the pendulum mechanism of bipedal walking. This work shows promise as a useful technique for analyzing exoskeleton performance to help children develop their natural gait pattern and to guide system optimization in the future for inclusion into clinical care.

Valence and concreteness in item recognition: Evidence against the affective embodiment account.

The Affective Embodiment Account posits that sensorimotor interactions play an important role in learning and processing concrete words whereas experiences from emotional states play an important role in learning and processing abstract words. Because of this, there should be greater enhancement of valence for abstract than for concrete words and therefore there should be an interaction between valence and concreteness. Although this prediction has been observed in a number of tasks, very few studies have looked specifically at memory. Three experiments are reported that assess whether valence interacts with concreteness in recognition. In Experiment 1, recognition of concrete words was better than abstract, but there was no difference as a function of whether the words were positive or negative and there was no interaction. Experiment 2 compared positive and neutral words and Experiment 3 compared negative and neutral words; in both, there was a concreteness effect but no effect of valence and no interaction. These results replicate previous findings that when positive and negative words are equated more fully, valence has no effect on recognition, and also suggest a limit on the scope of the Affective Embodiment Account.

Item‐based scoring and serial position of words generated during the Category Fluency Test: differences between controls and MCI subtypes

AbstractBackgroundThe order in which words are recalled during the 1‐minute Category Fluency Test (CFT) can be informative about the integrity of the underlying semantic memory (SM) system. Typically, the first entries tend to be easier exemplars and, as the category is explored in more depth during the course of the minute, words generated tend to become more difficult. We hypothesised that an item‐based scoring method that quantifies this increase in difficulty will help identify the semantic feature(s) most sensitive to the loss of SM integrity observed in people with a form of mild cognitive impairment (MCI).MethodTwo‐hundred participants (age: 58.68 ± 12.08 years) were sub‐divided into four clinical diagnostic groups: 50 healthy controls, 50 individuals with amnestic MCI, 50 individuals with non‐amnestic MCI and 50 individuals with subjective cognitive complaints but no objective deficits. No differences in age, years of education or gender existed across the four groups. All participants were administered a 1‐minute CFT (two categories: animals and fruits). Individual performance was scored word‐by‐word according to nine semantic features: age of acquisition, frequency, prevalence, recognition time, valence, arousal, dominance, sensorimotor interaction and concreteness. Correlation coefficients (Spearman’s rho) were calculated between each feature and the serial position of each word within the list. Correlations were then converted to z‐scores and analysed across the four groups with Kruskal‐Wallis one‐way analyses of variance.ResultThe z‐converted correlation between serial position and dominance was the only one differing across groups (at a p = 0.009). Bonferroni‐corrected post‐hoc tests showed a difference between healthy controls and individuals with amnestic MCI (p = 0.008). The decline in word dominance was significantly steeper in the group of amnestic MCI (z = ‐0.322) than in controls (z = ‐0.199).ConclusionThe study of SM is relevant to characterising the clinical mechanisms of normal and abnormal ageing. A procedure that focuses on CFT words difficulty and order of recall can complement classic methods that are typically used to detect loss of SM integrity. This pilot study indicates that ‘dominance’ is a semantic feature that might help characterise loss of SM integrity in individuals with amnestic MCI.

Personal Autonomy and (Digital) Technology: An Enactive Sensorimotor Framework

Many digital technologies, designed and controlled by intensive data-driven corporate platforms, have become ubiquitous for many of our daily activities. This has raised political and ethical concerns over how they might be threatening our personal autonomy. However, not much philosophical attention has been paid to the specific role that their hyper-designed (sensorimotor) interfaces play in this regard. In this paper, we aim to offer a novel framework that can ground personal autonomy on sensorimotor interaction and, from there, directly address how technological design affects personal autonomy. To do this, we will draw from enactive sensorimotor approaches to cognition, focusing on the central notion of habits, understood as sensorimotor schemes that, in networked relations, give rise to sensorimotor agency. Starting from sensorimotor agency as a basis for more complex forms of personal autonomy, our approach gives us grounds to analyse our relationship with technology (in general) and to distinguish between autonomy-enhancing and autonomy-diminishing technologies. We argue that, by favouring/obstructing the enactment of certain (networks of) habits over others, technologies can directly act upon our personal autonomy, locally and globally. With this in mind, we then discuss how current digital technologies are often being designed to be autonomy-diminishing (as is the case of “dark patterns” in design), and sketch some ideas on how to build more autonomy-enhancing digital technologies.

Supplemental Material for Negative Emotions Disrupt Intentional Synchronization During Group Sensorimotor Interaction

Supplemental Material for Negative Emotions Disrupt Intentional Synchronization During Group Sensorimotor Interaction

Plasticity of face-hand sensorimotor circuits after a traumatic brachial plexus injury.

Interactions between the somatosensory and motor cortices are of fundamental importance for motor control. Although physically distant, face and hand representations are side by side in the sensorimotor cortex and interact functionally. Traumatic brachial plexus injury (TBPI) interferes with upper limb sensorimotor function, causes bilateral cortical reorganization, and is associated with chronic pain. Thus, TBPI may affect sensorimotor interactions between face and hand representations. The aim of this study was to investigate changes in hand-hand and face-hand sensorimotor integration in TBPI patients using an afferent inhibition (AI) paradigm. The experimental design consisted of electrical stimulation (ES) applied to the hand or face followed by transcranial magnetic stimulation (TMS) to the primary motor cortex to activate a hand muscle representation. In the AI paradigm, the motor evoked potential (MEP) in a target muscle is significantly reduced when preceded by an ES at short-latency (SAI) or long-latency (LAI) interstimulus intervals. We tested 18 healthy adults (control group, CG), evaluated on the dominant upper limb, and nine TBPI patients, evaluated on the injured or the uninjured limb. A detailed clinical evaluation complemented the physiological investigation. Although hand-hand SAI was present in both the CG and the TBPI groups, hand-hand LAI was present in the CG only. Moreover, less AI was observed in TBPI patients than the CG both for face-hand SAI and LAI. Our results indicate that sensorimotor integration involving both hand and face sensorimotor representations is affected by TBPI.