Autistic traits in the general population do not correlate with a preference for associative information

Highlights

• We replicate the finding that humans have a preference for associative information.

• We hypothesized that autism traits are related to an enhancement of such preference.

• The present results show no relation between this preference and autism traits.

Abstract

Background

Associations and regularities in our environment can foster expectations and thereby help create a perceptually predictable world (e.g., a knife next to a plate predicts with high certainty a fork on the other side). Based on several observations, it has been suggested that individuals with autism spectrum disorder (ASD) have an above average tendency to prefer well-organized information or structured environments. Surprisingly, however, this tendency has not yet been tested under controlled experimental conditions.

Method

A recent study suggested that neurotypical adults prefer associative information, regardless of their semantic content. Therefore, in this study, we examined the relation of this preference bias to the scores of 123 neurotypical adults on questionnaires that measure autistic traits, known to co-vary with typical autism spectrum characteristics. Participants were presented with different configurations of meaningless abstract shapes. Some shapes were always presented in the exact same fixed configuration, and other shapes were always presented in different random configurations. In an unannounced subsequent evaluation task, participants were required to indicate which shapes they preferred.

Results

We replicate the observation that people exhibit a general preference for shapes that were presented in fixed configurations. However, there were no correlations between autistic traits and this general preference.

Conclusions

Our findings suggest the preference for associative information in ASD might be less general than first thought, or restricted to more complex (social) situations or other levels of information processing. We outline specific guidelines for future systematic investigations into the hypothesized increased preference for associative information in ASD.

Introduction

A common idea about people with autism spectrum disorder (ASD) is that they prefer things to happen in always the exact same way, and experience unexpected changes in their environments as particularly stressful. Indeed, individuals with ASD commonly feel overwhelmed in environments where perceptual variability is naturally high (e.g. supermarkets, Van De Cruys et al., 2014) and some attempt to decrease this variability in several ways, for example by engaging in motor stereotypies (e.g. hand flapping before the eyes; American Psychiatric Association, 2013). Moreover, neurotypical individuals who are more sensitive to perceptual information more often show (non-clinical) autistic behaviors, such as an insistence on sameness (Robertson & Simmons, 2013). In fact, these symptoms were already described by Kanner in the first scientific description of children with autism: “[Their] behavior is governed by an anxiously obsessive desire for the maintenance of sameness” (Kanner, 1943; p. 245). Also in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), insistence on sameness is described as a core symptom of ASD. Some examples are: “extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take same route or eat same food every day” (American Psychiatric Association, 2013, p. 50).

Despite the widespread adoption of the idea that insistence on sameness is related to the autism spectrum, the precise mechanisms underlying these patterns of behavior received surprisingly little attention in autism research. In trying to unravel this interesting feature of the autism spectrum, a straightforward prediction would be that individuals high on the autism spectrum should show a stronger preference for stimuli that show more statistical regularities with other stimuli in their environment, hereafter referred to as associative information. Because information carrying statistical regularities about the environment considerably helps our interactions with the external world, associative information is thought to carry an inherently positive value, leading people to seek out and affectively prefer this type of associative information (Ogawa & Watanabe, 2011; Trapp, Shenhav, Bitzer, & Bar, 2015; Van de Cruys & Wagemans, 2011). From this, the hypothesis follows almost naturally that individuals high on the autism spectrum should show an even higher preference. As the implicit learning literature has shown that individuals with ASD often show intact learning of contextual regularities (Barnes et al., 2008; Brown, Aczel, Jiménez, Kaufman, & Grant, 2010; for a meta-analysis, see Foti, De Crescenzo, Vivanti, Menghini, & Vicari, 2015), it is unlikely that the relation between preference for associative information and ASD-like traits would be influenced by differences in recognizing associative information in the environment in ASD.

Many experimental findings hint towards a heightened preference for associative information in ASD. For example, it has been found that children with ASD display less exploratory behavior in a novel environment than their peers (Kawa and Pisula, 2013, Pierce and Courchesne, 2001, Pisula, 2003), tend to perseverate in building repetitive patterns (Frith, 1970), and experience problems with task switching (Panerai, Tasca, Ferri, Arrigo, & Elia, 2014). In a similar vein, recent theories have started to (re-)emphasize the problems people with ASD might experience while making predictions about their environment (Gomot and Wicker, 2012, Pellicano and Burr, 2012, Sinha et al., 2014), or while dealing with deviations from these predictions (Lawson, Rees, & Friston, 2014; Van De Cruys et al., 2014). It also follows from these predictive coding accounts, that individuals with stronger ASD-like traits should show a higher preference for associative information. However, while these studies are consistent with the idea of an increased preference for associative information, they were not set up to specifically test this hypothesis, and therefore only address the research question indirectly at best. For example, the stimuli in these playroom studies were not (and could hardly be) controlled for learning history or affective connotations (Kawa and Pisula, 2013, Pierce and Courchesne, 2001, Pisula, 2003). In a similar vein, other studies were mainly interested in the manipulation and measurements of other variables (e.g., executive functions, Panerai et al., 2014) which confounded the study of a preference for associative information.

Therefore, to our knowledge, it remains to be tested whether the autism spectrum is indeed related to an increased preference for associative stimuli in the lab, when all other factors (i.e., semantic or affective content) are controlled for. To this end, we set out to test whether there is a correlation between ASD-like traits and the strength of the naturally occurring preference for associative information (i.e., visually organized stimuli) in neurotypical adults. Psychological and neurophysiological autism spectrum characteristics are known to correlate with questionnaire scores across the typical (non-ASD) population, and many studies have shown that correlational experimental studies in a neurotypical population can yield meaningful insights for our knowledge of ASD (Grinter et al., 2009, Robertson and Simmons, 2013; Stewart, Watson, Allcock, & Yaqoob, 2009; Walter, Dassonville, & Bochsler, 2009), and can also allow for more informed hypothesis testing in clinical populations.

Our study employed, and was inspired by, a recent paradigm by Trapp et al. (2015) that was developed to measure the general preference for associative information in a healthy adult population. In the task of Trapp et al. (2015), participants observed abstract visual shapes that were always presented in groups of four (i.e., quadruplets). However, some of these shapes were always presented with the same other three shapes in the exact same position (i.e., fixed quadruplets), whereas other shapes were always presented with other shapes on random positions (i.e., random quadruplets). In other words, some shapes were presented in an associative context (i.e., predictive of the co-occurrence of the other three shapes), whereas other shapes were not. In a subsequent unannounced preference judgment task, participants were presented with pairs of shapes of which one shape had been part of a fixed quadruplet, and the other had been part of a random quadruplet. Interestingly, participants showed a significant above-chance preference for the abstract shapes that had been part of fixed quadruplets (hereafter referred to as preference effect), consistent with the hypothesis that people prefer associative information (Trapp et al., 2015).

Based on the clinical relationship between ASD and the insistence on sameness, we hypothesized that people with stronger autistic characteristics should show an enhanced preference effect. Using different levels of autistic traits as a proxy for the clinical population allows us to test our hypothesis in a large group of subjects (though potential results should of course be replicated in a clinical population − see also discussion). Specifically, we assessed the Autism-Spectrum Quotient (Baron-Cohen, Wheelwright, Skinner, Martin, & Clubley, 2001) and the Social Responsiveness Scale − Adult version (Constantino et al., 2003). Because insistence on sameness has been proposed as a way to cope with disturbed sensory processes that lead to sensory overload (e.g. Van De Cruys et al., 2014), we also assessed the Adolescent/Adult Sensory Profile questionnaire (Brown & Dunn, 2002; known to co-vary with autistic traits; Crane, Goddard, & Pring, 2009; Hilton et al., 2010, Lundqvist, 2015). As such, we aimed to test the hypothesis that there would be a positive correlation between the preference effect and autistic traits and sensory peculiarities related to the autism spectrum. In addition, we wanted to exclude the possibility that the relation between preference for associative information and ASD-like traits would be influenced by differences in recognizing associative information in the environment in ASD. Therefore, we evaluated whether performance in recognizing associative shape configurations differed as a function of ASD-like traits.