Publications by authors named "Poletti M"

Eating disorders (EDs) pose significant challenges to mental and physical health, particularly among adolescents and young adults, with the COVID-19 pandemic exacerbating risk factors. Despite advancements in psychosocial and pharmacological treatments, improvements remain limited. Early intervention in EDs, inspired by the model developed for psychosis, emphasizes the importance of timely identification and treatment initiation to improve prognosis.

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Visual perception is characterized by known asymmetries in the visual field; human's visual sensitivity is higher along the horizontal than the vertical meridian, and along the lower than the upper vertical meridian. These asymmetries decrease with decreasing eccentricity from the periphery to the center of gaze, suggesting that they may be absent in the 1-deg foveola, the retinal region used to explore scenes at high-resolution. Using high-precision eyetracking and gaze-contingent display, allowing for accurate control over the stimulated foveolar location despite the continuous eye motion at fixation, we investigated fine visual discrimination at different isoeccentric locations across the foveola and parafovea.

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Article Synopsis
  • Researchers combined a high-speed external display (360 fps) with an adaptive optics scanning laser ophthalmoscope (AOSLO) to enhance human foveal imaging for psychophysics experiments.
  • A custom pupil relay was developed for precise stimulus viewing and was validated to correct refractive errors while achieving a high Strehl ratio, ensuring image clarity.
  • The system achieved excellent eye-tracking capabilities, allowing for accurate localization of visual stimuli and capturing detailed images of the human central fovea, while overcoming previous limitations in temporal and spatial resolution.
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Crowding, the phenomenon of impaired visual discrimination due to nearby objects, has been extensively studied and linked to cortical mechanisms. Traditionally, crowding has been studied extrafoveally; its underlying mechanisms in the central fovea, where acuity is highest, remain debated. While low-level oculomotor factors are not thought to play a role in crowding, this study shows that they are key factors in defining foveal crowding.

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Subtle distortions of the experience of lived space have long been associated with schizophrenia. Although a body-centric transformation of space is considered an essential component of anomalous subjective experience in schizophrenia, its impact on the 2 major body-centric spatial constructs, that is, personal space (PS) and peripersonal space (PPS), is still not clear. This systematic review and meta-analysis have been set up to: (1) summarize the evidence on putative extensional differences of PS and PPS in schizophrenia as compared with controls, and (2) evaluate the quality and the limitations of available studies on the topic.

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Schizophrenia spectrum disorders (SSD) typically have a diagnostically recognizable onset in young adulthood, yet it is not unusual that help-seeking due to initial SSD-related clinical manifestations emerge in earlier developmental phases, such as childhood and adolescence. Varieties of SSD manifestations in children and adolescents can be distinguished according to variations in clinical expressivity, severity and timing (i.e.

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Continuous casting is the most common method for producing steel into semi-finished shapes like billets or slabs. Throughout this process, steel experiences mechanical and thermal stresses, which influence its mechanical properties. During continuous casting, decreased formability in steel components leads to crack formation and failure.

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Broadening prediction efforts from imminent psychotic symptoms to neurodevelopmental vulnerabilities can enhance the accuracy of diagnosing severe mental disorders. Early interventions, especially during adolescence, are vital as these disorders often follow a long prodromal phase of neurodevelopmental disturbances. Child and adolescent mental health services should lead a developmentally-sensitive model for timely, effective detection and intervention.

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Article Synopsis
  • Multiple Complex Developmental Disorder (MCDD) is a condition that affects various areas of development and could be seen as lying between autism and childhood-onset schizophrenia, but interest in it has decreased over time.
  • This study systematically reviewed literature on MCDD to evaluate its current significance, finding only 16 relevant studies that varied widely in methodology and focus.
  • The analysis revealed that children with MCDD tended to experience more paranoia and psychotic symptoms compared to those with autism, highlighting a potential diagnostic gap that warrants further investigation.
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Humans explore visual scenes by alternating short fixations with saccades directing the fovea to points of interest. During fixation, the visual system not only examines the foveal stimulus at high resolution, but it also processes the extrafoveal input to plan the next saccade. Although foveal analysis and peripheral selection occur in parallel, little is known about the temporal dynamics of foveal and peripheral processing upon saccade landing, during fixation.

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The concept of basic Self-disorders (SD) captures the experiential aspects associated with vulnerability to schizophrenia spectrum disorders (SSD). SD emerge prior to, and constitute the underlying structure for, the emergence of major diagnostic symptoms, including positive psychotic ones. SD are also detectable in populations with familial risk for SSD.

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The construct of Clinical-High Risk for Psychosis (CHR-P) identifies young help-seeking subjects in putative prodromal stages of psychosis and is a central component of the Early Intervention (EI) paradigm in Mental Health, aimed at facilitating rapid entry into appropriate care pathways to prevent the onset of psychosis or mitigate is biopsychosocial consequences. This approach, which promotes an innovative culture of care for early, at risk situations, is inspired by a clinical staging concept as a guide to optimal treatment. The objective of this article is to map the existing guidelines in the field of CHR-P treatment recommendations, examine overlaps and differences, and critically evaluate blind spots to be addressed in future guideline updated.

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What determines spatial tuning in the visual system? Standard views rely on the assumption that spatial information is directly inherited from the relative position of photoreceptors and shaped by neuronal connectivity. However, human eyes are always in motion during fixation, so retinal neurons receive temporal modulations that depend on the interaction of the spatial structure of the stimulus with eye movements. It has long been hypothesized that these modulations might contribute to spatial encoding, a proposal supported by several recent observations.

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Background: Typical propagation-based X-ray phase contrast imaging (PB-PCI) experiments using polyenergetic sources are tested in very ideal conditions: low-energy spectrum (mainly characteristic X-rays), small thickness and homogeneous materials considered weakly absorbing objects, large object-to-detector distance, long exposure times and non-clinical detector.

Objective: Explore PB-PCI features using boundary conditions imposed by a low power polychromatic X-ray source (X-ray spectrum without characteristic X-rays), thick and heterogenous materials and a small area imaging detector with high low-detection radiation threshold, elements commonly found in a clinical scenario.

Methods: A PB-PCI setup implemented using a microfocus X-ray source and a dental imaging detector was characterized in terms of different spectra and geometric parameters on the acquired images.

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By combining an external display operating at 360 frames per second with an Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO) for human foveal imaging, we demonstrate color stimulus delivery at high spatial and temporal resolution in AOSLO psychophysics experiments. A custom pupil relay enables viewing of the stimulus through a 3-mm effective pupil diameter and provides refractive error correction from -8 to +4 diopters. Performance of the assembled and aligned pupil relay was validated by measuring the wavefront error across the field of view and correction range, and the as-built Strehl ratio was 0.

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Grain refinement by plastic deformation during conventional TIG welding can help to compensate for the loss of mechanical properties of welded joints. The thermomechanical welding (TMW) tests were performed on S700MC steel with different combinations of TIG arc energy and high frequency hammering over three target cooling times (t = 5s, 15s, and 25s). Additionally, the effect of initial microstructures on the weld joint quality was analysed by testing three materials conditions: hot-rolled (as-received) and cold-rolled with 10% and 30% thickness reductions, respectively.

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Article Synopsis
  • Emerging evidence suggests that taking antipsychotics before experiencing psychosis increases the risk of transitioning to psychosis in individuals at high risk (CHR-P), and this is not due to prior high-risk conditions.
  • The study aimed to investigate whether this increased risk follows a dose-response relationship, using chlorpromazine equivalent doses (CPZ-ED) to assess dosage impact.
  • A systematic review included eight studies involving 290 CHR-P individuals and found that 66 transitioned to psychosis, indicating a connection between baseline antipsychotic exposure and the likelihood of developing psychosis.
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In prior art, advances in adaptive optics scanning laser ophthalmoscope (AOSLO) technology have enabled cones in the human fovea to be resolved in healthy eyes with normal vision and low to moderate refractive errors, providing new insight into human foveal anatomy, visual perception, and retinal degenerative diseases. These high-resolution ophthalmoscopes require careful alignment of each optical subsystem to ensure diffraction-limited imaging performance, which is necessary for resolving the smallest foveal cones. This paper presents a systematic and rigorous methodology for building, aligning, calibrating, and testing an AOSLO designed for imaging the cone mosaic of the central fovea in humans with cellular resolution.

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Microsaccades, the tiny gaze relocations that occurr during fixation, have been linked to covert attention deployed degrees away from the center of gaze. However, the link between attention and microsaccades is deeper in that it also unfolds at the foveal scale. Here, we have examined the spatial grain of pre-microsaccadic attention across the 1° foveola.

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Psychopathological conditions in adolescence and young adulthood often result from an altered neurodevelopment already phenotypically expressed in childhood. Child and adolescent mental health services are ideally placed to intercept in the developmental trajectories of younger adolescents and contribute to the early detection of a risk for psychosis, as proposed by Salazar de Pablo and Arango (2023, Child and Adolescent Mental Health), opening a debate to which we contribute. The early detection of a specific risk for psychosis and of a broader risk for severe mental illness requires an understanding of the clinical staging of psychosis, neurodevelopmental antecedents of severe mental illness and of heterotypic trajectories between childhood phenotypes and adult disorders.

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