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

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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

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

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

Planning and understanding action in autism

L’autismo è una sindrome dello sviluppo del bambino caratterizzata da un comportamento sociale atipico, da disturbi della comunicazione, sia verbale sia non verbale, e da comportamenti ripetitivi. E’ stata per lungo tempo considerata una patologia delle cosiddette funzioni superiori del cervello ed inizialmente classificata fra le psicosi. Tuttavia gli sviluppi degli ultimi anni di ricerca hanno evidenziato come il disturbo dello spettro autistico accanto alle alterazioni caratteristiche in ambito sociocomunicativo ed emotivo, comporti anche particolari deficit di organizzazione del movimento. Alcuni anni fa è stata avanzata l’ipotesi che alla base dell’incapacità dei bambini con autismo di entrare in relazione con gli altri (di capire gli altri) vi sia un malfunzionamento del sistema specchio. Dati sperimentali hanno dimostrato che effettivamente nei soggetti affetti da autismo vi è un deficit di attivazione del sistema specchio durante l’osservazione di azioni compiute da altri

Understanding Actions and the Intentions of Others: The Basic Neural Mechanism

In this study, we first briefly review the basic properties of a particular set of neurons that discharge both when the individuals execute a specific action and when they observe another individual doing a similar action. These neurons are called mirror neurons. We then show that mirror neurons mediate our capacity to understand actions done by others. In the second part of the study we discuss the role of the mirror mechanism in intention understanding. We conclude with a review of recent data suggesting that a deficit in the mirror neuron mechanism may underlie some aspects of autism.

System neuroscience: Past, present, and future

In this review, we discuss first the anatomical and lesion studies that allowed the localization of fundamental functions in the cerebral cortex of primates including humans. Subsequently, we argue that the years from the end of the Second World War until the end of the last century represented the “golden age” of system neuroscience. In this period, the mechanisms—not only the localization—underlying sensory, and in particular visual functions were described, followed by those underlying cognitive functions and housed in temporal, parietal, and premotor areas. At the end of the last century, brain imaging techniques were developed that allowed the assessment of the functions of different cortical areas in a more precise and sophisticated way. However, brain imaging tells little about the neural mechanisms underlying functions. Furthermore, the brain imaging suffers from 3 major problems: time is absent, the data are merely correlative and the testing is often not ecological. We conclude our review discussing the possibility that these pitfalls might be overcome by using intracortical recordings (eg stereo-EEG), which have millisecond time resolution, allow direct electrical stimulation of specific sites, and finally enable to study patients while freely moving

Phonological and lexical motor facilitation during speech listening: a transcranial magnetic stimulation study.

In the present study, we used transcranial magnetic stimulation (TMS) to investigate the influence of phonological and lexical properties of verbal items on the excitability of the tongue's cortical motor representation during passive listening. In particular, we aimed to clarify if the difference in tongue motor excitability found during listening to words and pseudo-words [Fadiga, L., Craighero, L., Buccino, G., Rizzolatti, G., 2002. Speech listening specifically modulates the excitability of tongue muscles: a TMS study. European Journal of Neuroscience 15, 399-402] is due to lexical frequency or to the presence of a meaning per se. In order to do this, we investigated the time-course of tongue motor-evoked potentials (MEPs) during listening to frequent words, rare words, and pseudo-words embedded with a double consonant requiring relevant tongue movements for its pronunciation. Results showed that at the later stimulation intervals (200 and 300 ms from the double consonant) listening to rare words evoked much larger MEPs than listening to frequent words. Moreover, by comparing pseudo-words embedded with a double consonant requiring or not tongue movements, we found that a pure phonological motor resonance was present only 100 ms after the double consonant. Thus, while the phonological motor resonance appears very early, the lexical-dependent motor facilitation takes more time to appear and depends on the frequency of the stimuli. The present results indicate that the motor system responsible for phonoarticulatory movements during speech production is also involved during speech listening in a strictly specific way. This motor facilitation reflects both the difference in the phonoarticulatory characteristics and the difference in the frequency of occurrence of the verbal material