Perceptual Grouping in Autism Spectrum Disorder: An Exploratory Magnetoencephalography Study

Visual information is organised according to visual grouping principles. In visual grouping tasks individuals with ASD have shown equivocal performance. We explored neural correlates of Gestalt grouping in individuals with and without ASD. Neuromagnetic activity of individuals with (15) and without (18) ASD was compared during a visual grouping task testing grouping by proximity versus similarity. Individuals without ASD showed stronger evoked responses with earlier peaks in response to both grouping types indicating an earlier neuronal differentiation between grouping principles in individuals without ASD. In contrast, individuals with ASD showed particularly prolonged processing of grouping by similarity suggesting a high demand of neural resources. The neuronal processing differences found could explain less efficient grouping performance observed behaviourally in ASD.

General movements assessment: A bibliometric analysis

This bibliometric analysis provides an in-depth exploration of the scholarly landscape in the field of Prechtl General Movement Assessment (GMA) research, spanning the period from 1961 to 2023. It offers valuable insights into the evolutionary trajectory and global impact of GMA. The study employs a longitudinal approach, meticulously tracking trends in scholarly output, international collaborations, and authorship patterns. Notably, our findings reveal a significant increase in GMA-related publications, highlighting the growing prominence of this field. The dominance of Australia and Austria in scholarly contributions underscores their pivotal roles. International collaborations are prominent, with active participation from European nations and the Americas. However, it is essential to acknowledge certain limitations, including potential data source biases and a reliance on English-language publications. This analysis serves as a valuable resource for stakeholders in the field, emphasizing the need for ongoing evaluation and collaborative efforts to enhance GMA applications and further our understanding of its clinical implications.

The time course of holistic processing is similar for face and non-face Gestalt stimuli

There is evidence that holistic processing of faces and other stimuli rich in Gestalt perceptual grouping cues recruit overlapping mechanisms at early processing stages, but not at later stages where faces and objects of expertise likely overlap. This has led to suggestions of dual pathways supporting holistic processing; an early stimulus-based pathway (supporting processing of stimuli rich in perceptual grouping cues) and an experience-based pathway (supporting processing of object of expertise), with both pathways supporting face processing. Holistic processing markers are present when upright faces are presented for as little as 50-ms. If the overlap between holistic processing of faces and stimuli rich in grouping cues occurs early in processing, markers of holistic processing for these Gestalt stimuli should be present as early as those for faces. In Experiment 1, we investigate the time-course of the emergence of holistic processing markers for face and non-face Gestalt stimuli. The emergence of these markers for faces and the Gestalt stimuli was strikingly similar; both emerged with masked presentations as little as 50-ms. In Experiment 2, where the stimulus presentation was not masked, thus the presentation duration, but not the post-presentation perceptual processing, was constrained, patterns of holistic processing for these stimuli still did not diverge. These findings are consistent with an early, and possibly extended, temporal locus for the overlap in the holistic processing of faces and non-face stimuli rich in grouping cues.

Gestalt Perception and the Experience of the Social Space in Autism: A Case Study

Phenomenological approaches suggest that the bodily presence of others has a profound influence on the experience of social spaces. This intimate relationship is particularly evident in mental disorders. Investigations into the nature of intersubjectivity in various pathologies indicate that modifications to the capacity for social perception play a key role in determining the manners in which the social space is experienced and felt. This paper aims to examine the interviewing relation of social perception and the experience of space and its consequences in autism spectrum disorder (ASD). This is done through a phenomenologically informed analysis of the functioning of social perception in ASD. Our account proposes that the atypical socio-perceptual patterns exhibited by people with autism significantly reduce the capacity to grasp the context of the situation, which facilitates and intensifies negative feelings that are intertwined with the experience of social spaces. This novel understanding draws on the idea that ASD involves a fundamental difficulty to establish a gestalt perception of social scenes. The evidence we discuss suggests that this anomaly in the operation of social perception also modulates the experience of the social space. Failing to perceive the wholeness of the situation means that people with autism often experience the social space as unfamiliar, confusing, uncertain, and unsafe, rather than feeling familiar and understood in the embodied presence of others. As a result, autistic subjects may experience difficulty evaluating the outcomes of hazardous circumstances, which poses a risk to their well-being, particularly in borderline situations. This suggestion is elaborated through the tragic occurrences that led to the killing of Eyad al-Hallaq, a 32-year-old Palestinian with autism.

The role of shape complexity in the detection of closed contours

The detection of contours in noise has been extensively studied, but the detection of closed contours, such as the boundaries of whole objects, has received relatively little attention. Closed contours pose substantial challenges not present in the simple (open) case, because they form the outlines of whole shapes and thus take on a range of potentially important configural properties. In this paper we consider the detection of closed contours in noise as a probabilistic decision problem. Previous work on open contours suggests that contour complexity, quantified as the negative log probability (Description Length, DL) of the contour under a suitably chosen statistical model, impairs contour detectability; more complex (statistically surprising) contours are harder to detect. In this study we extended this result to closed contours, developing a suitable probabilistic model of whole shapes that gives rise to several distinct though interrelated measures of shape complexity. We asked subjects to detect either natural shapes (Exp. 1) or experimentally manipulated shapes (Exp. 2) embedded in noise fields. We found systematic effects of global shape complexity on detection performance, demonstrating how aspects of global shape and form influence the basic process of object detection.

A new Mooney test

Since its introduction in 1957, the Mooney test has continued to see active use in studies of visual perception, in studies using brain imaging, and in clinical research. Mooney's original version is of limited length, however, and was designed to be administered by time-consuming personal interview. We have developed a new, extended version of the Mooney test that is suitable for online testing and for use in a test-retest paradigm. The Mooney-Verhallen Test (MVT) comprises 144 trials, takes on average less than 10 min to complete, and has a Spearman-Brown-corrected test-retest reliability of ρ = .89. We outline our methods for developing the stimuli and for selecting the final stimulus set, and we present the results from two rounds of testing on two independent samples of 374 participants and 505 participants, respectively. The test is freely available for scientific use.

Investigating vision in schizophrenia through responses to humorous stimuli

The visual environment of humans contains abundant ambiguity and fragmentary information. Therefore, an early step of vision must disambiguate the incessant stream of information. Humorous stimuli produce a situation that is strikingly analogous to this process: Funniness is associated with the incongruity contained in a joke, pun, or cartoon. Like in vision in general, appreciating a visual pun as funny necessitates disambiguation of incongruous information. Therefore, perceived funniness of visual puns was implemented to study visual perception in a sample of 36 schizophrenia patients and 56 healthy control participants. We found that both visual incongruity and Theory of Mind (ToM) content of the puns were associated with increased experienced funniness. This was significantly less so in participants with schizophrenia, consistent with the gestalt hypothesis of schizophrenia, which would predict compromised perceptual organization in patients. The association of incongruity with funniness was not mediated by known predictors of humor appreciation, such as affective state, depression, or extraversion. Patients with higher excitement symptoms and, at a trend level, reduced cognitive symptoms, reported lower funniness experiences. An open question remained whether patients showed this deficiency of visual incongruity detection independent of their ToM deficiency. Humorous stimuli may be viewed as a convenient method to study perceptual processes, but also fundamental questions of higher-level cognition.