Psicologia

Aim: Research on Autism Spectrum Disorders (ASD) has mainly focused on the study of social behavioral deficits (e.g. imitation, eye gaze, play, etc.). These studies have emphasized the high-level impairments that lead to abnormal social interaction in ASD. However, as important as the study of social behavior in ASD, is research on lower-level processes that might contribute to the emergence and development of the atypical social behaviors that characterize this condition. Perceptual differences constitute one such factor. Here, we aim to investigate the possible influence of specific visual motion perception deficits in conceptual processing. Materials and Methods: We compared the performance of children with ASD, with that of children with moderate to severe learning disorders (MLD) or typical development (TD) on a series of computerized tasks. These tasks assessed motion detection in non-social and socially embedded backgrounds or contexts. Results: The results provide evidence for speed-selective impairments in processing socially embedded targets in ASD. Conclusions: Based on these findings, we suggest that low-level perceptual deficits might play an important role in the development of social impairments.

"Responses to pictures of famous tennis and soccer athletes are
slower when the responding effector is a hand or foot, respectively, indicating that visual recognition of individuals characterized by skilled motor behavior interferes with the motor reactivity of non-proficient observers. By contrast, directly viewing actions induces motor facilitation, suggesting that actions are mapped in the observers’ motor system. Here, we used single-pulse Transcranial Magnetic Stimulation to determine 1) whether observing and recognizing the identity of famous tennis and soccer athletes selectively reduce the corticospinal excitability of arm and leg representations (categorization), 2) whether any athlete-related inhibition effect contrasts the facilitation associated with direct action observation (categorization 1 action), and 3) whether the
classic action observation--related facilitation effect is found when viewing ‘‘in action’’ nonathlete models (action). In 3 experiments, we found that amplitude of motor evoked potentials (MEPs) recorded from leg and arm muscles gradually shifted from reduction to facilitation, moving from the categorization to the action observation tasks. Thus, semantic derivation of motor skills is reflected in limb-specific reduction of MEP amplitude, indicating that even abstract action knowledge is embodied in the motor system and that mapping
others’ actions on the basis of categorization or of their direct
observation relies on competing functional mechanisms."

Educational Neuroscience is currently raising high attention by the educational and neuroscientific community. However, society has created too many expectations concerning what Neuroscience can bring to Education. With this study, we aim to identify eventual distorted expectations of the teachers and propose ways to overcome these. This study was carried out in Portugal with 30 participating schools, where 627 questionnaires were answered by teachers from Preschool to High School. Our results show that there are still misunderstandings concerning the Portuguese teachers‟ views about the links between Neuroscience and Education. More collaborative efforts between professionals of both fields are needed for the field of Educational Neuroscience to succeed.

"The ability to predict the actions of others is quintessential for effective social interactions, particularly in competitive contexts (e.g. in sport) when knowledge about upcoming movements allows anticipating rather than reacting to opponents. Studies suggest that we predict what others are doing by using our own motor system as an internal forward model and that the fronto-parietal action observation network (AON) is fundamental for this ability. However, multiple-duty cells dealing with action perception and execution have been found in a variety of cortical regions. Here we used functional magnetic resonance imaging to explore, in expert basketball athletes and novices, whether the ability to make early predictions about the fate of sport-specific actions (i.e. free throws) is underpinned by neural regions beyond the classical AON. We found that, although involved in action prediction, the fronto-parietal AON was similarly activated in novices and experts. Importantly, athletes exhibited relatively greater activity in the extrastriate body
area during the prediction task, probably due to their expert reading of the observed action kinematics. Moreover, experts exhibited higher activation in the bilateral inferior frontal gyrus and in the right anterior insular cortex when producing errors, suggesting that they might become aware of their own errors. Correct action prediction induced higher posterior insular cortex activity in experts and higher orbito-frontal activity in novices, suggesting that body awareness is important for performance monitoring in experts, whereas novices rely more on higher-order decision-making strategies. This functional reorganization highlights the tight relationship between action anticipation, error awareness and motor expertise leading to body-related processing and differences in decision-making processes."

Based on a considerable and consistent amount of data showing low level visual processing deficits in children with developmental disorders such as Autism Spectrum Disorder (ASD) and Williams Syndrome (WS), we decided to investigate the basis and consequences (i.e. impact on behavioral and social phenotype) of these deficits in these two clinical groups. The first question we addressed was: What low level visual deficits do these two disorders portray? This is, what low level visual deficits characterize these disorders independently of their mental and chronological age? (Study 1). We investigated deficits in visual motion sensitivity in 9 children with ASD, 10 children with WS and 96 typically developing children (TDC). We created six Random Dot Kinematogram tasks to assess sensitivities to different motion types. Within-group score patterns were very heterogeneous across tasks for both clinical groups. However, participants with ASD showed consistent deficits in a ‘Single Mobile’ task and participants with WS showed consistent deficits in a ‘Motion Coherence’ task. We discussed the data in terms of the dissociations found in the motion detection deficit patterns.

We suggested a genetic basis (extension of the deletion) in WS to account for the variability found. To explain the variability in ASD we suggested that low level visual deficits might be correlated with the placement on the social spectrum (Study 2). If deficits in visual perception exist at an early developmental stage they might hinder the correct processing of very fine social signs that involve motion or visual attention change (e.g. ocular saccades, facial expressions, etc.). We developed five computer-generated tasks to assess sensitivity to different motion speeds, attention shifting, motion coherence, ecological motion and form through motion. We tested 23 children with ASD, 36 children with moderate to severe learning disabilities (MLD) and 70 TDC. A social cognition score was also attributed to the children in the clinical groups, assessed by means of a parent interview. Indeed, visual processing deficit patterns were correlated with social cognition in ASD, but also in MLD and TD. However, the stronger deficit patterns in ASD allowed prediction of a stronger pattern of deficits in processing of social concepts. Moreover, detection of human made motion was no different than detection of a single mobile moving at a speed of 400pix/sec for all groups. But speed seems to affect children with ASD when processing socially embed targets. We discussed these results by revisiting the importance of low-level motion signals in the processing of social signs. A correlation between low level visual deficits and the position on the autistic social spectrum could help in predicting future social deficits at an early age and contribute to an adapted early intervention.

In another study (Study 3), we investigated the nature of one specific visual processing deficit in WS – visual processing bias to local elements composing a global shape. Impairments in visuospatial processing exhibited by individuals with WS have been ascribed to a local processing bias. We developed three computergenerated and pen and paper experiments investigating visual processing of geometric Navon stimuli. Thirteen children with WS exhibited the same sensitivity to global figures as 22 matched controls, confirming no local bias in perception. In a reproduction task the children with WS did show a local bias with respect to controls, but only when the target being copied was present. When drawing from memory, subjects with WS produced a heterogeneous pattern of answers. We proposed that subjects with WS are unable to disengage their attention from local elements during the planning stage of reproduction (visual-conflict hypothesis).

With these three studies we aimed to contribute to the specification of the importance of low level visual processing in the development of the unique behavioral and social phenotypes that characterize these two clinical groups.

Keywords: Autism Spectrum Disorder, Williams Syndrome, visual perception, visual motion deficits, local-global
deficits, social cognition.