Disturbances of multisensory processing in schizophrenia spectrum disorders: a behavioural and neurophysiological account

Self-disorders have long been considered as a central nucleus of the schizophrenic experience. It has been suggested that such self-disturbances might be associated with abnormal multisensory integration and abnormal bodily self-awareness. The primary goal of this thesis was to explore the behavioural and neurophysiological markers of self-disturbances in schizophrenia and in high schizotypy (i.e. a sub-clinical trait linked to schizophrenia). Specifically, we aimed at (i) investigating the temporal acuity in individuals with low and high schizotypy (ii) measuring aspects of the neural responses to multisensory integration in low and high schizotypes (iii) exploring how body representation abnormalities in both schizophrenic patients and high schizotypes affect basic processes of self-perception. In line with previous research showing a reduced multisensory acuity in schizophrenia, results from Chapter Three revealed a significant relationship between the temporal window within which two stimuli are integrated (i.e. TWI), and schizotypal personality traits; namely, higher schizotypal traits are associated with wider TWIs. In Chapter Four, we provided evidence of a selective relationship between the TWI for visuo-tactile stimuli and the individual beta frequency (IBF), i.e, slower IBFs accounts for larger TWIs, and between the TWI and schizotypy, i.e. wider TWIs are linked to higher schizotypal traits. In Chapter Five, we have demonstrated that patients with schizophrenia possess more malleable body representations and that these abnormalities are linked to early markers of vulnerability to the disorder (i.e. basic symptoms). Finally, findings from Chapter Six revealed that the abnormalities in bodily self-awareness observed in schizophrenia might extend to schizotypy, suggesting that such abnormalities could represent a trait marker for schizophrenia proneness. All in all, our results suggest that the abnormalities in multisensory integration and bodily awareness observed in schizophrenia spectrum disorders might produce a distortion in the structure of self-experience and contribute to the emergence of the disorder

Sensory Processing, Gastrointestinal Symptoms and Parental Feeding Practices in The Explanation of Food Selectivity: Clustering Children with and Without Autism

Children with Autism Spectrum Disorders are a group of neurodevelopmental disorders (ASD) and compared to Typically Developing Children (TDC), experience significantly more feeding problems. Food selectivity is a complex phenomenon that involves individual and contextual factors (sensory abnormalities, severity of behavioral problems, gastrointestinal disorders, parenting styles and so on). The clarification of these key factors is the aim of the current study, comparing a group of children with ASD with a group of TDC on different variables such as food selectivity, anthropometric measures, gastrointestinal symptoms, diet, sensory processing and caregiver feeding practices. Moreover, the same variables described above are studied using a classification model for both groups. Results display that parenting style, sensory anomalies and gastrointestinal symptoms were associated with food refusal of children. Moreover, it is possible to observe similar profiles in children with feeding problems in both groups. Autism Spectrum Disorders (ASD) are a group of neurodevelopmental disorders characterized by social communication deficit and a tendency to engage in a pattern of restricted and repetitive behaviors, in which sensory issues are included (American Psychiatric Association [APA], [1]). Children with ASD, compared to Typically Developing Children (TDC), experience significantly more feeding problems [2], with food selectivity being the most frequently reported. Food selectivity could be operationally defined on the basis of the occurrence of the following behaviours: food refusal, limited repertoires of food, high frequency single food intake [3]. Several research studies observed a prevalence between 70% and 80% of food selectivity among children with ASD [4-6], despite parents never having described their children as in appetent [7]. Klein and Nowak (1999) [8] found that 53% of children were reluctant to try new foods. Whiteley, Rodgers, and Shattok (2000) [9] indicated a prevalence of 83% of children with a restricted repertoire of foods eaten. Similarly, Schreck and Williams (2006) [6] found that 57% of children refused food, while 72% accepted limited variety. A more consistent prevalence was found by Lockner, Crowe, and Skipper (2008), [10] who thought that new foods refusal in children with ASD was higher compared to TDC (95% vs. 47%). Furthermore, children with ASD were characterized also by a limited variety of food intake (16% vs. 58%). However, Bandini et al. (2010) [3] found lower rates of refusal in both groups compared to previous studies (41.7% vs. 18.9%). Methodological differences in research studies such as different approach mechanisms may have accounted for conflicting results. Food selectivity in ASD is really important because it is linked to health risks for children, and it may require some medical intervention [11]. In fact, in a recent review by the same authors, BMI and other anthropometric values in children with autism seem to differ from that of TDC, along with nutritional insufficiency [12]. However, in this survey as well as other recent studies [13,14] this difference was not always confirmed, with the literature still seeming incomplete. At the same time several studies tried to identify some of the causes for food selectivity in children with ASD. Some researchers investigated the role of motor coordination disorders and/or gastrointestinal problems. Children with praxis difficulties may lack the necessary motor skills to adequately handle food, leading to negative emotions avoidance [15]. Also, researchers have found contrasting results in Gastrointestinal Disorders (GID). According to a recent survey, a higher frequency of GID may be associated with a more severe food selectivity in children with ASD [16], while for others, the two phenomena seem largely independent in children with autism [17]. Indeed, children with and without autism experiencing frequently bowel problems and/or gastroesophageal reflux could display more feeding-related problems, since they could try to avoid foods associated with adverse circumstances. On the other hand, many children with autism commonly well-defined as picky or choosy eaters do not show gastrointestinal issues. In fact, other authors explained food selectivity in children with ASD as a consequence of repetitive behaviour and restricted interests [18,19]. However, the most accepted etiological hypothesis would seem to postulate a relationship between sensory perception abnormalities and rejection of food [20] both from children with typical and atypical development. As shown by Nadon, Feldman, Dunn, and Gisel (2011) [21], almost 90% of children with ASD show impairment in sensory processing information, including a hypo and or hypersensitivity to environmental stimuli. The differences in sensory processing in children with ASD have been well documented [22]. These abnormalities have been associated with both behavioural and emotional problems [23,24] and the severity of symptoms [25]. Since foods have several properties which can stimulate sense organs, it is possible that children who have sensory perception alteration might refuse them to a greater extent as they are more or less stimulating. From interviews with parents and behavioural observations it has been proven that children with ASD are adverse towards food characteristics such as texture, smell, taste and temperature [10,14,23,26-28], yet other food properties seem to be more important to them such as brand, packaging (patterns/colours), food presentation and even cutlery [4,6,9]. Finally, eating behaviours not only have a biological matrix but are also influenced by social and cultural variables [29], therefore it’s possible that in addition to the individual dimensions, parental feeding practices can also play a significant role in food selectivity. Currently, a research study [13] evaluated the parental feeding style and the food selectivity in children with ASD, indicating strategies as prompting/encouragement as the most used among parents. This direction of research is of particular interest not only scientifically but also in the way of application. If a relationship between parental feeding practices and food selectivity is found, it will be possible to devise intervention programs aimed at promoting functional parenting styles in order to achieve healthy eating behaviors. Hence, the aim of the current study is to compare a group of children with ASD with a group of TDC on different variables such as food selectivity, weight, gastrointestinal disorders, diet, sensory process and caregiver feeding practices. To sum up, we want to explore the following research questions: a) if the group of children with ASD shows more levels of food selectivity than controls; b) if the children with ASD report lower scores of BMI than controls; c) if the clinical group shows more sensory abnormalities than controls; d) if an association between food selectivity, BMI, GID, sensory dimensions and parental feeding styles can be established in both groups of children, e) if it is possible to discover similar profiles of children in both groups

Higher proneness to multisensory illusions is driven by reduced temporal sensitivity in people with high schizotypal traits

A coherent sense of self, typically altered in schizophrenia, is accompanied by a coherent ability to integrate sensory information. According to the idea of a psychosis continuum, high schizotypal traits in the general population may be associated to higher proneness to multisensory illusions, akin to schizophrenia. We directly tested this hypothesis by means of the double-flash illusion in participants with low and high schizotypal scores. We confirmed the higher proneness to illusions in the high-schizotypal group. Crucially, such higher proneness was fully explained by a significantly reduced temporal sensitivity to integrate sensory information. We conclude that reduced temporal sensitivity accounts for enhanced proneness to illusions in people at higher risk and represents an early marker of psychosis

ANALISI NON DISTRUTTIVE: MODELLAZIONE 3D MEDIANTE TERMOGRAFIA PER I BENI CULTURALI

Nowadays, unfortunately the decay’s state of a big number of Cultural Heritage artifacts, requires a restauration work to be kept in a good state maintaining their integrity and duration. However, minor preventive intervention is necessary to reduce the resources to be allocated to more economically demanding restauration activities, allowing their accessibility to the public. A non-destructive analysis plays a fundamental role to understand e identify a possible degradation state. Thermography analyses are central to determine the thermo-absorbing capacities of the constituent elements ‘artifact and the possible material’s changes or lesions’ presence, otherwise identifiable to the naked eye. This paper illustrates a methodology to create a 3D model by combining, through soft computing techniques and digital photogrammetry, the point clouds obtained from the processing of thermographic images and RGB; in this way it is possible to obtain a geometrically accurate model that also reports the thermographic values. This methodology is applied on concrete sample (in which the presence of cracks was already known). The goal is to experiment with a process that lets the use of thermal sensors alongside digital cameras in the photogrammetric field in order to obtain a product that allows to extrapolate the geometric and thermal information of the object of study

The temporal sensitivity to the tactile-induced Double Flash Illusion mediates the impact of beta oscillations on schizotypal personality traits.

The coherent experience of the self and the world depends on the ability to integrate vs. segregate sensory information. Optimal temporal integration between the senses is mediated by oscillatory properties of neural activity. Previous research showed reduced temporal sensitivity to multisensory events in schizotypy, a personality trait linked to schizophrenia. Here we used the tactile-induced Double-Flash-Illusion (tDFI) to investigate the tactile-to-visual temporal sensitivity in schizotypy, as indexed by the temporal window of illusion (TWI) and its neural underpinnings. We measured EEG oscillations within the beta band, recently shown to correlate with the tDFI. We found individuals with higher schizotypal traits to have wider TWI and slower beta waves accounting for the temporal window within which they perceive the illusion. Our results indicate reduced tactile-to-visual temporal sensitivity to mediate the effect of slowed oscillatory beta activity on schizotypal personality traits. We conclude that slowed oscillatory patterns might constitute an early marker for psychosis proneness

The temporal sensitivity to the tactile-induced double flash illusion mediates the impact of beta oscillations on schizotypal personality traits

The coherent experience of the self and the world depends on the ability to integrate vs. segregate sensory information. Optimal temporal integration between the senses is mediated by oscillatory properties of neural activity. Previous research showed reduced temporal sensitivity to multisensory events in schizotypy, a personality trait linked to schizophrenia. Here we used the tactile-induced Double-Flash-Illusion (tDFI) to investigate the tactile-to-visual temporal sensitivity in schizotypy, as indexed by the temporal window of illusion (TWI) and its neural underpinnings. We measured EEG oscillations within the beta band, recently shown to correlate with the tDFI. We found individuals with higher schizotypal traits to have wider TWI and slower beta waves accounting for the temporal window within which they perceive the illusion. Our results indicate reduced tactile-to-visual temporal sensitivity to mediate the effect of slowed oscillatory beta activity on schizotypal personality traits. We conclude that slowed oscillatory patterns might constitute an early marker for psychosis proneness

Body structural representation in schizotypy

A deficient sense of self, typically observed in schizophrenia spectrum disorders, is often accompanied by abnormalities in bodily perception and awareness. These abnormalities are seemingly among the most powerful predictive factors for the onset of schizophrenic illnesses. According to the hypothesis of the psychosis continuum, high schizotypal traits in the general population may be characterized by a progressive sense of detachment from one's lived body. Building upon previous research that found an abnormal Body Structural Representation (BSR) in individuals with schizophrenia, this study aims to extend these findings to schizotypy. To investigate this, we utilized the Finger Localization Task (FLT), in which participants must identify the finger touched by the experimenter, and the In Between Task (IBT), in which two fingers are touched and participants must specify the number of fingers in between the two stimulated fingers. We found that individuals with high schizotypy were significantly less accurate than individuals with low schizotypy in determining the spatial configuration of their own fingers relative to each other. Most significantly, performances on both tasks were negatively correlated with the score on the Dissociative Experiences Scale (DES). These findings support the hypothesis that the progressive loss of one's sense of self is associated with abnormal bodily experiences and dissociative symptomatology which may represent a potential marker for schizophrenia proneness

Body structural representation in schizotypy

A deficient sense of self, typically observed in schizophrenia spectrum disorders, is often accompanied by abnormalities in bodily perception and awareness. These abnormalities are seemingly among the most powerful predictive factors for the onset of schizophrenic illnesses. According to the hypothesis of the psychosis continuum, high schizotypal traits in the general population may be characterized by a progressive sense of detachment from one's lived body. Building upon previous research that found an abnormal Body Structural Representation (BSR) in individuals with schizophrenia, this study aims to extend these findings to schizotypy. To investigate this, we utilized the Finger Localization Task (FLT), in which participants must identify the finger touched by the experimenter, and the In Between Task (IBT), in which two fingers are touched and participants must specify the number of fingers in between the two stimulated fingers. We found that individuals with high schizotypy were significantly less accurate than individuals with low schizotypy in determining the spatial configuration of their own fingers relative to each other. Most significantly, performances on both tasks were negatively correlated with the score on the Dissociative Experiences Scale (DES). These findings support the hypothesis that the progressive loss of one's sense of self is associated with abnormal bodily experiences and dissociative symptomatology which may represent a potential marker for schizophrenia proneness

Using Tablet Applications for Children with Autism to Increase the Cognitive and Social skills

Several researchers along with technicians have been developing software and hardware to support and/or replace the standard method of teaching for children with autism spectrum disorders (ASDs) and/or other developmental disabilities. Moreover, computer-based intervention and electronic tablets have shown benefits for people with special needs increasing their independence, academic and cognitive skills, social communication, and leisure time. Therefore, the aim of the current study is to evaluate the effectiveness of three tablet applications created to enhance specific abilities of children with ASD (attention, vocabulary, and imitation), who followed applied behavior analysis treatment (ABA) compared with the internal control group (CG). Training lasted 4 weeks for 15 children selected in a randomized way, while the CG followed only the behavioral therapy. To sum up, we want to respond to three questions: (1) whether the experimental group (EG) using the applications obtains greater progress within standard therapy in comparison to the CG, (2) whether the real skills of children examined at baseline have an impact on the application scores, and (3) whether the graphic features of the applications influence the motivation of children during training. At postintervention assessment, the EG showed higher progress within standard therapy than the internal CG even though these differences didn’t overreach the significance level. However, the probability of making progress in mastered targets at postintervention assessment was higher for the EG than the CG. To conclude, the current study demonstrates the capability of tablet applications to reproduce effective educational training for children with autism

Free-Operant Preference Assessment to Increase the Mand Variety of a Child with Autism Spectrum Disorder

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