Silent shapes and shapeless sounds: the robustness of the diminished crossmodal correspondences effect in autism spectrum conditions

Abstract

We performed a registered replication of the Oberman and Ramachandran (Soc Neurosci 3(3-4):348-355, 2008) study on the 'kiki/bouba' effect in autism spectrum conditions (ASC). The aim of the study was to test the robustness of the diminished crossmodal correspondences effect in autism, but also to verify whether this effect is not an artifact of differences in intelligence. We tested a Polish-speaking sample of 21 participants with ADOS-confirmed autism spectrum conditions (mean age 15.90) and 21 age-(mean age 15.86), sex-and IQ-matched neurotypical control participants. Procedure closely followed the replicated study. Participants' task was to match five pairs of unfamiliar words and shapes. Matching words and shapes had similar supramodal characteristics that allowed the match. We report partial replication of the diminished 'kiki/bouba' effect in individuals with ASC compared to the neurotypical control group. However, we found that nonverbal intelligence also significantly contributed to task performance, but only in participants with autism, suggesting a compensatory role of intelligence. Finally, the effect of autism severity (measured by ADOS classification) was significant-crossmodal correspondences were weaker in individuals with autism, compared to those with autism spectrum diagnosis.

People With High Autistic Traits Show Fewer Consensual Crossmodal Correspondences Between Visual Features and Tastes

“…Here, we observed that our participants with higher AQ scores tended to make fewer of the consensual color–taste/shape–color associations, suggesting that the autistic traits play a role in constructing crossmodal correspondences. This result was consistent with previous findings that individuals with autism showed atypical sensory processing and deficits in binding sensory information across modalities ( Oberman and Ramachandran, 2008 ; Foss-Feig et al, 2010 ; Cascio et al, 2012a ; Kujala et al, 2013 ; Occelli et al, 2013 ; Visser et al, 2013 ; Stevenson et al, 2014b , 2016 ; Wada et al, 2014 ; Gold and Segal, 2017 ; Król and Ferenc, 2020 ; Yaguchi and Hidaka, 2020 ), as evident in audio–visual processing ( Gelder et al, 1991 ; Mongillo et al, 2008 ; Irwin et al, 2011 ; Collignon et al, 2013 ; Bebko et al, 2014 ; Stevenson et al, 2014b ; Hidaka and Yaguchi, 2018 ), audio–tactile processing ( Russo et al, 2010 ), and visual–tactile processing ( Cascio et al, 2012a ; Noel et al, 2020 ). For example, Occelli et al (2013) found that children with ASD showed lower proportion of expected takete–maluma associations, and the performance varied as a function of the severity of the symptomatology.…”

“…The impaired ability to integrate multisensory information in individuals with ASD may arise from an underlying impairment in perceiving the relationships between cross-modal inputs ( Stevenson et al, 2014a ). For example, the most studied “bouba–kiki” effect (i.e., people associate rounded shapes with words like “bouba” or “maluma,” and spiky shapes with words like “kiki” or “takete”; Köhler, 1947 ) was reported to be less pronounced in individuals with autism compared to controls ( Oberman and Ramachandran, 2008 ; Occelli et al, 2013 ; Gold and Segal, 2017 ; Król and Ferenc, 2020 ). Oberman and Ramachandran (2008) found that children with ASD do not show the “bouba–kiki” effect that neurologically typical adults and children show (the neurotypical children chose expected sound–shape associations 88% of the time, while children with ASD chose only 56% of the time, compared to the chance of 50%).…”

Exploring Group Differences in the Crossmodal Correspondences

“…The research that has been published to date shows that those scoring high on the autism spectrum appear to be less sensitive to certain of the correspondences that have been demonstrated in the normal population, such as, for example, the so-called bouba-kiki effect (e.g., Gold and Segal, 2017;Król and Ferenc, 2020;Stewart et al, 2016). In one of the first studies of its kind to document such individual differences, Oberman and Ramachandran (2008) provided some preliminary evidence for a reduced strength of cross-modal correspondences in a group of 10 individuals with autism spectrum disorder (ASD).…”

People with higher autistic traits show stronger binding for color–shape associations

“…Moreover, individuals with ASD have been shown to exhibit impaired multisensory integration and show less pronounced crossmodal correspondences. For example, the well-known "Bouba-Kiki" effect (i.e., people associate rounded shapes with words like "bouba" or "maluma," and spiky shapes with words like "kiki" or "takete"; Köhler, 1947) was weaker in individuals with ASDs than in controls (Gold & Segal, 2017;Król & Ferenc, 2020;Oberman & Ramachandran, 2008;Occelli et al, 2013). Chen et al (2021) reported that individuals with higher autistic traits showed fewer consensual color-taste (e.g., yellow-sour taste) and CSAs using a questionnaire survey.…”