Spatiotemporal dynamics during processing of abstract and concrete verbs: An ERP study

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Do mirror neurons really mirror and do they really code for action goals?

Attempts to elucidate the properties of mirror neurons (MNs) have seen considerable effort expended and thousands of papers published. Nevertheless, the field is dogged by uncertainty and confusion: Not only is it harder than ever to say exactly what a MN is, but there is increasing ambiguity about their basic field properties and putative functions. Here we challenge the two properties of MNs which have excited most interest; that they ‘mirror’, and that they encode goals

Bodily Expression of Social Initiation Behaviors in ASC and non-ASC children: Mixed Reality vs. LEGO Game Play

This study is part of a larger project that showed the potential of our mixed reality (MR) system in fostering social initiation behaviors in children with Autism Spectrum Condition (ASC). We compared it to a typical social intervention strategy based on construction tools, where both mediated a face-to-face dyadic play session between an ASC child and a non-ASC child. In this study, our first goal is to show that an MR platform can be utilized to alter the nonverbal body behavior between ASC and non-ASC during social interaction as much as a traditional therapy setting (LEGO). A second goal is to show how these body cues differ between ASC and non-ASC children during social initiation in these two platforms. We present our first analysis of the body cues generated under two conditions in a repeated-measures design. Body cue measurements were obtained through skeleton information and characterized in the form of spatio-temporal features from both subjects individually (e.g. distances between joints and velocities of joints), and interpersonally (e.g. proximity and visual focus of attention). We used machine learning techniques to analyze the visual data of eighteen trials of ASC and non-ASC dyads. Our experiments showed that: (i) there were differences between ASC and non-ASC bodily expressions, both at individual and interpersonal level, in LEGO and in the MR system during social initiation; (ii) the number of features indicating differences between ASC and non-ASC in terms of nonverbal behavior during initiation were higher in the MR system as compared to LEGO; and (iii) computational models evaluated with combination of these different features enabled the recognition of social initiation type (ASC or non-ASC) from body features in LEGO and in MR settings. We did not observe significant differences between the evaluated models in terms of performance for LEGO and MR environments. This might be interpreted as the MR system encouraging similar nonverbal behaviors in children, perhaps more similar than the LEGO environment, as the performance scores in the MR setting are lower as compared to the LEGO setting. These results demonstrate the potential benefits of full body interaction and MR settings for children with ASC.EPSR

Expert–novice differences in brain function of field hockey players

The aims of this study were to use functional magnetic resonance imaging to examine the neural bases for perceptual-cognitive superiority in a hockey anticipation task. Thirty participants (15 hockey players, 15 non-hockey players) lay in an MRI scanner while performing a video-based task in which they predicted the direction of an oncoming shot in either a hockey or a badminton scenario. Video clips were temporally occluded either 160 ms before the shot was made or 60 ms after the ball/shuttle left the stick/racquet. Behavioral data showed a significant hockey expertise × video-type interaction in which hockey experts were superior to novices with hockey clips but there were no significant differences with badminton clips. The imaging data on the other hand showed a significant main effect of hockey expertise and of video type (hockey vs. badminton), but the expertise × video-type interaction did not survive either a whole-brain or a small-volume correction for multiple comparisons. Further analysis of the expertise main effect revealed that when watching hockey clips, experts showed greater activation in the rostral inferior parietal lobule, which has been associated with an action observation network, and greater activation than novices in Brodmann areas 17 and 18 and middle frontal gyrus when watching badminton videos. The results provide partial support both for domain-specific and domain-general expertise effects in an action anticipation task

Seeing is believing: Neural mechanisms of action-perception are biased by team membership

Group identification can lead to a biased view of the world in favor of “in-group” members. Studying the brain processes that underlie such in-group biases is important for a wider understanding of the potential influence of social factors on basic perceptual processes. In this study, we used functional magnetic resonance imaging (fMRI) to investigate how people perceive the actions of in-group and out-group members, and how their biased view in favor of own team members manifests itself in the brain. We divided participants into two teams and had them judge the relative speeds of hand actions performed by an in-group and an out-group member in a competitive situation. Participants judged hand actions performed by in-group members as being faster than those of out-group members, even when the two actions were performed at physically identical speeds. In an additional fMRI experiment, we showed that, contrary to common belief, such skewed impressions arise from a subtle bias in perception and associated brain activity rather than decision-making processes, and that this bias develops rapidly and involuntarily as a consequence of group affiliation. Our findings suggest that the neural mechanisms that underlie human perception are shaped by social context

Activation patterns during action observation are modulated by context in mirror system areas

The role of the mirror system in action understanding has been widely debated. Some authors have suggested that the mirror system plays an important role in action understanding (Rizzolatti and Sinigaglia, 2010), whereas others have claimed that direct evidence to support this view is lacking (Hickok, 2009). If mirror neurons have an active role in action understanding rather than passive visuomotor transformation during action observation, they should respond differently to the observation of actions depending on the intentions of the observer. In this fMRI study, twenty participants observed identical actions under different instruction contexts. The task was either to understand the actions, identify the physical features of the actions, or passively observe the actions. A multi-voxel pattern analysis revealed unique patterns of activation in ventral premotor cortex and inferior parietal lobule across the different contexts. The results suggest that ventral premotor and inferior parietal areas respond differently to observed actions depending on the mindset of the observer. This is consistent with the view that these regions do not merely process observed actions passively, but play an active role in action understanding

The Dynamics of Sensorimotor Cortical Oscillations during the Observation of Hand Movements: An EEG Study

Background The observation of action done by others determines a desynchronization of the rhythms recorded from cortical central regions. Here, we examined whether the observation of different types of hand movements (target directed, non-target directed, cyclic and non-cyclic) elicits different EEG cortical temporal patterns. Methodology Video-clips of four types of hand movements were shown to right-handed healthy participants. Two were target directed (grasping and pointing) motor acts; two were non-target directed (supinating and clenching) movements. Grasping and supinating were performed once, while pointing and clenching twice (cyclic movements). High-density EEG was recorded and analyzed by means of wavelet transform, subdividing the time course in time bins of 200 ms. The observation of all presented movements produced a desynchronization of alpha and beta rhythms in central and parietal regions. The rhythms desynchronized as soon as the hand movement started, the nadir being reached around 700 ms after movement onset. At the end of the movement, a large power rebound occurred for all bands. Target and non-target directed movements produced an alpha band desynchronization in the central electrodes at the same time, but with a stronger desynchronization and a prolonged rebound for target directed motor acts. Most interestingly, there was a clear correlation between the velocity profile of the observed movements and beta band modulation. Significance Our data show that the observation of motor acts determines a modulation of cortical rhythm analogous to that occurring during motor act execution. In particular, the cortical motor system closely follows the velocity of the observed movements. This finding provides strong evidence for the presence in humans of a mechanism (mirror mechanism) mapping action observation on action execution motor programs

The multiform motor cortical output: kinematic, predictive and response coding

Observing actions performed by others entails a subliminal activation of primary motor cortex reflecting the components encoded in the observed action. One of the most debated issues concerns the role of this output: Is it a mere replica of the incoming flow of information (kinematic coding), is it oriented to anticipate the forthcoming events (predictive coding) or is it aimed at responding in a suitable fashion to the actions of others (response coding)? The aim of the present study was to disentangle the relative contribution of these three levels and unify them into an integrated view of cortical motor coding. We combined transcranial magnetic stimulation (TMS) and electromyography recordings at different timings to probe the excitability of corticospinal projections to upper and lower limb muscles of participants observing a soccer player performing: (i) a penalty kick straight in their direction and then coming to a full stop, (ii) a penalty kick straight in their direction and then continuing to run, (iii) a penalty kick to the side and then continuing to run. The results show a modulation of the observer's corticospinal excitability in different effectors at different times reflecting a multiplicity of motor coding. The internal replica of the observed action, the predictive activation, and the adaptive integration of congruent and non-congruent responses to the actions of others can coexist in a not mutually exclusive way. Such a view offers reconciliation among different (and apparently divergent) frameworks in action observation literature, and will promote a more complete and integrated understanding of recent findings on motor simulation, motor resonance and automatic imitation

Atypical basic movement kinematics in autism spectrum conditions

Individuals with autism spectrum conditions have difficulties in understanding and responding appropriately to others. Additionally, they demonstrate impaired perception of biological motion and problems with motor control. Here we investigated whether individuals with autism move with an atypical kinematic profile, which might help to explain perceptual and motor impairments, and in principle may contribute to some of their higher level social problems. We recorded trajectory, velocity, acceleration and jerk while adult participants with autism and a matched control group conducted horizontal sinusoidal arm movements. Additionally, participants with autism took part in a biological motion perception task in which they classified observed movements as ‘natural’ or ‘unnatural’. Results show that individuals with autism moved with atypical kinematics; they did not minimize jerk to the same extent as the matched typical control group, and moved with greater acceleration and velocity. The degree to which kinematics were atypical was correlated with a bias towards perceiving biological motion as ‘unnatural’ and with the severity of autism symptoms as measured by the Autism Diagnostic Observation Schedule. We suggest that fundamental differences in movement kinematics in autism might help to explain their problems with motor control. Additionally, developmental experience of their own atypical kinematic profiles may lead to disrupted perception of others’ actions

Intention Understanding in Autism

When we observe a motor act (e.g. grasping a cup) done by another individual, we extract, according to how the motor act is performed and its context, two types of information: the goal (grasping) and the intention underlying it (e.g. grasping for drinking). Here we examined whether children with autistic spectrum disorder (ASD) are able to understand these two aspects of motor acts. Two experiments were carried out. In the first, one group of high-functioning children with ASD and one of typically developing (TD) children were presented with pictures showing hand-object interactions and asked what the individual was doing and why. In half of the “why” trials the observed grip was congruent with the function of the object (“why-use” trials), in the other half it corresponded to the grip typically used to move that object (“why-place” trials). The results showed that children with ASD have no difficulties in reporting the goals of individual motor acts. In contrast they made several errors in the why task with all errors occurring in the “why-place” trials. In the second experiment the same two groups of children saw pictures showing a hand-grip congruent with the object use, but within a context suggesting either the use of the object or its placement into a container. Here children with ASD performed as TD children, correctly indicating the agent's intention. In conclusion, our data show that understanding others' intentions can occur in two ways: by relying on motor information derived from the hand-object interaction, and by using functional information derived from the object's standard use. Children with ASD have no deficit in the second type of understanding, while they have difficulties in understanding others' intentions when they have to rely exclusively on motor cues