Steven Vanmarcke

Rapid gist perception of meaningful real-life scenes: exploring individual and gender differences in multiple categorization tasks

In everyday life, we are generally able to dynamically understand and adapt to socially (ir)elevant encounters, and to make appropriate decisions about these. All of this requires an impressive ability to directly filter and obtain the most informative aspects of a complex visual scene. Such rapid gist perception can be assessed in multiple ways. In the ultrafast categorization paradigm developed by Simon Thorpe et al. (1996), participants get a clear categorization task in advance and succeed at detecting the target object of interest (animal) almost perfectly (even with 20 ms exposures). Since this pioneering work, follow-up studies consistently reported population-level reaction time differences on different categorization tasks, indicating a superordinate advantage (animal versus dog) and effects of perceptual similarity (animals versus vehicles) and object category size (natural versus animal versus dog). In this study, we replicated and extended these separate findings by using a systematic collection of different categorization tasks (varying in presentation time, task demands, and stimuli) and focusing on individual differences in terms of e.g., gender and intelligence. In addition to replicating the main findings from the literature, we find subtle, yet consistent gender differences (women faster than men).

In the Eye of the Beholder: Rapid Visual Perception of Real-Life Scenes by Young Adults with and Without ASD

Typically developing (TD) adults are able to extract global information from natural images and to categorize them within a single glance. This study aimed at extending these findings to individuals with autism spectrum disorder (ASD) using a free description open-encoding paradigm. Participants were asked to freely describe what they saw when looking at briefly presented real-life photographs. Our results show subtle but consistent group-level differences. More specifically, individuals with ASD spontaneously reported the presence of people in the display less frequently than TD participants, and they grasped the gist of the scene less well. These findings argue for a less efficient rapid feedforward processing of global semantic aspects and a less spontaneous interpretation of socially salient information in ASD.

Ultra-Rapid Categorization of Meaningful Real-Life Scenes in Adults With and Without ASD

In comparison to typically developing (TD) individuals, people with autism spectrum disorder (ASD) appear to be worse in the fast extraction of the global meaning of a situation or picture. Ultra-rapid categorization [paradigm developed by Thorpe et al. (Nature 381:520–522, 1996)] involves such global information processing. We therefore tested a group of adults with and without ASD, without intellectual disability, on a set of ultra-rapid categorization tasks. Individuals with ASD performed equally well as TD individuals except when the task required the categorization of social interactions. These results argue against a general deficit in ultra-rapid gist perception in people with ASD, while suggesting a more specific problem with the fast processing of information about social relations.

Individual differences in spatial frequency processing in scene perception: the influence of autism-related traits

ABSTRACT Previous research suggested that coarse (High Spatial Frequency or HSF) and fine (Low Spatial Frequency or LSF) spatial information are flexibly used at different stages of processing during scene recognition in daily life. We tried to replicate and extend these findings by presenting non-social real-life scenes either as a normal picture, solely defined by LSF or HSF information, or using hybrid images consisting of overlaid LSF and HSF scene information. These were used as (in)congruent prime stimuli, modulating the rapid detection of a normal target picture in a 2-Alternative Forced Choice (2-AFC) categorization task (manmade versus natural). Our results indicated that coarse spatial information was more effective with shorter prime presentation times and fine spatial information required a longer prime presentation to influence participant performance. Interestingly, higher scores on the Autism-Spectrum Quotient questionnaire modified the impact of HSF prime information on target identification and influenced performance when ambiguous hybrid prime information preceded the categorization task.

Hierarchical Letters in ASD: High Stimulus Variability Under Different Attentional Modes

Studies using hierarchical patterns to test global precedence and local–global interference in individuals with ASD have produced mixed results. The current study focused on stimulus variability and locational uncertainty, while using different attentional modes. Two groups of 44 children with and without ASD completed a divided attention task as well as a global and local selective attention task. The results revealed global-to-local and local-to-global interference in ASD, to the same extent as in the TD group. Both groups struggled with the same type of stimuli (i.e., ignoring the global level information) and performed similar in all three tasks. Future studies on (visual) information processing in ASD should pursue the impact of stimulus noise and trial-by-trial uncertainty further.

The Time-Course of Ultrarapid Categorization: The Influence of Scene Congruency and Top-Down Processing:

Although categorization can take place at different levels of abstraction, classic studies on semantic labeling identified the basic level, for example, dog, as entry point for categorization. Ultrarapid categorization tasks have contradicted these findings, indicating that participants are faster at detecting superordinate-level information, for example, animal, in a complex visual image. We argue that both seemingly contradictive findings can be reconciled within the framework of parallel distributed processing and its successor Leabra (Local, Error-driven and Associative, Biologically Realistic Algorithm). The current study aimed at verifying this prediction in an ultrarapid categorization task with a dynamically changing presentation time (PT) for each briefly presented object, followed by a perceptual mask. Furthermore, we manipulated two defining task variables: level of categorization (basic vs. superordinate categorization) and object presentation mode (object-in-isolation vs. object-in-context). In contradiction with previous ultrarapid categorization research, focusing on reaction time, we used accuracy as our main dependent variable. Results indicated a consistent superordinate processing advantage, coinciding with an overall improvement in performance with longer PT and a significantly more accurate detection of objects in isolation, compared with objects in context, at lower stimulus PT. This contextual disadvantage disappeared when PT increased, indicating that figure-ground separation with recurrent processing is vital for meaningful contextual processing to occur.

The influence of age and gender on ultra-rapid categorization

ABSTRACT In ultra-rapid categorization studies, population-level reaction time differences in performance are consistently reported. In a previous study, we replicated these findings and also observed consistent gender differences in young adults (18–24 years old). We now tested a group of adolescents (11–16 years old) on the same ultra-rapid categorization tasks. Results indicated that age had a significant impact on categorization performance. Although women outperformed men during adulthood, this effect reversed in adolescence (boys faster than girls). This gender x age interaction for categorizing meaningful (non-)social visual scenes could be caused by gender-specific development processes underlying emotion regulation strategies and/or context sensitivity.

The Use of Prior Knowledge for Perceptual Inference Is Preserved in ASD

An amorphous collection of black and white patches (so-called Mooney images) can be perceived dramatically differently before versus after exposure to the natural source image. Prior experience causes the patches to (re)organize and fit together in a meaningful whole. Given recent hypotheses on a weaker role of priors in perception in individuals with autism spectrum disorders (ASD), we looked at improvements in recognition accuracy for Mooney images, before and after exposure to their source image, in typically developing (TD) individuals varying in ASD-like traits, and in a clinical group of adolescents with ASD (versus matched TD sample). We found typical prior-based performance improvements irrespective of ASD-like traits or ASD diagnosis, suggesting that the fast formation and application of specific priors is preserved in ASD. Together with earlier studies reporting intact use of other types of perceptual priors, these findings narrow down the candidate Bayesian accounts that are plausible for ASD.

Intact perceptual bias in autism contradicts the decreased normalization model

One recent, promising account of Autism Spectrum Disorders (ASD) situates the cause of the disorder in an atypicality in basic neural information processing, more specifically in how activity of one neuron is modulated by neighboring neurons. The canonical neural computation that implements such contextual influence is called divisive (or suppressive) normalization. The account proposes that this normalization is reduced in ASD. We tested one fundamental prediction of this model for low-level perception, namely that individuals with ASD would show reduced cross-orientation suppression (leading to an illusory tilt perception). 11 young adults with an ASD diagnosis and 12 age-, gender-, and IQ-matched control participants performed a psychophysical orientation perception task with compound grating stimuli. Illusory tilt perception did not differ significantly between groups, indicating typical divisive normalization in individuals with ASD. In fact, all individuals with ASD showed a considerable orientation bias. There was also no correlation between illusory tilt perception and autistic traits as measured by the Social Responsiveness Scale. These results provide clear evidence against the decreased divisive normalization model of ASD in low-level perception, where divisive normalization is best characterized. We evaluate the broader existing evidence for this model and propose ways to salvage and refine the model.

Parenting adolescents with ASD: A multimethod study: Parenting Adolescents with ASD

A number of studies have concluded that parents of children with ASD experience high levels of parenting stress. However, little is known about their parenting behaviors. Especially few studies investigated parenting in adolescence, although this period is associated with additional challenges for both adolescents and their parents. In the present study, a multi‐method approach was used, combining data from a self‐report questionnaire and observation of mother‐child interactions during different semi‐structured (e.g., inventing and building a vehicle of the future with construction toys) and structured tasks (e.g., solving marble maze). Linear mixed models (LMM) were used to compare the means of parenting behaviors among mothers of adolescents with (n = 44) and without ASD (n = 38), aged 12 to 16 years old. During the observations, mothers of adolescents with ASD showed more sensitivity and creativity, compared to the general population control group. In addition, mothers in the ASD group reported on the self‐report questionnaire to adapt the environment more, for example, by establishing routines. Furthermore, this study investigated the role of maternal characteristics, that is, ASD characteristics and parenting stress. Parenting stress was associated with less self‐reported positive parenting. Higher levels of ASD characteristics of the mother were related to more negativity and less sensitivity during the observation, and more self‐reported harsh punishment and adapting the environment. This study additionally examined whether the impact of these maternal characteristics was the same across the two groups. Whereas group by parenting stress interaction effects were not significant for any of the observed and self‐reported parenting behaviors, significant group by ASD characteristics interaction effects were noticed for self‐reported harsh punishment and adapting the environment. Autism Res 2018, 11: 1000–1010.