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

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. Electronic supplementary material The online version of this article (10.1007/s00426-019-01163-9) contains supplementary material, which is available to authorized users.

1. Compared to the neurotypical control group, participants with ASC will not display a signi cant kiki/bouba e ect, indicating a de cit in multisensory integration. Firstly, there will be a signi cant di erence between the two groups, indicating a smaller kiki/bouba e ect in the ASC group. Secondly, the responses of the ASC groups will not be signi cant di erent from random responses, while the responses in the control group will di er signi cantly from random responses, indicating a presence of the multisenory integration e ect. 2. There will be no correlation between overall IQ as measured by the Wechsler test and the presence of the kiki/bouba e ect in either of the groups. 3. There will be a correlation between autism severity as measured by ADOS and the presence of the kiki/bouba e ect and the kiki/bouba e ect, with more severe ASC related to more random responses in the kiki/bouba test. 4. There will be a similar correlation between the AQ test and the kiki/bouba e ect, particularly strong for the imagination scale (related to exibility of thinking and creativity. Preregistration is designed to make clear the distinction between con rmatory tests, speci ed prior to seeing the data, and exploratory analyses conducted after observing the data. Therefore, creating a research plan in which existing data will be used presents unique challenges. Please select the description that best describes your situation. Please do not hesitate to contact us if you have questions about how to answer this question (prereg@cos.io). If you indicate that you will be using some data that already exist in this study, please describe the steps you have taken to assure that you are unaware of any patterns or summary statistics in the data. This may include an explanation of how access to the data has been limited, who has observed the data, or how you have avoided observing any analysis of the speci c data you will use in your study. The purpose of this question is to assure that the line between con rmatory and exploratory analysis is clear.
I have collected data from two participants so far. I have not analyzed these data.
Please describe the process by which you will collect your data. If you are using human subjects, this should include the population from which you obtain subjects, recruitment e orts, payment for participation, how subjects will be selected for eligibility from the initial pool (e.g. inclusion and exclusion rules), and your study timeline. For studies that don't include human subjects, include information about how you will collect samples, duration of data gathering e orts, source or location of samples, or batch numbers you will use.
We will recruit ASC participants of both sexes, in the age range of 12-30. The control group will be age and sex matched. The control group will also be matched in terms of the overall IQ as measured by the Wechsler test. We will strive to match both verbal and non-verbal IQ if possible. All ASC participants will have their diagnosis con rmed with ADOS 2. The exclusion criteria will be intellectual disability, epilepsy, vision not corrected to normal, schizophrenia and bipolar disorder (but not depression). All participants will receive voucher cards to thank them for their time and will be reimbursed for inconvenience and expenses. Data collection will run between February and June 2017.
no le selected Describe the sample size of your study. How many units will be analyzed in the study? This could be the number of people, birds, classrooms, plots, interactions, or countries included. If the units are not individuals, then describe the size requirements for each unit. If you are using a clustered or multilevel design, how many units are you collecting at each level of the analysis?
There will be 30 participants in each group (ASC and control). The sample size may changed slightly depending on recruitment -if we are unable to reach 30 ASC participants, it will be a bit lower. However, if recruitment is going well, we will strive to recruit a higher number of participants.
This could include a power analysis or an arbitrary constraint such as time, money, or personnel.
The original study had 10 participants, our goal is to at least double that. We will strive to test 30, but given the time and personnel and nancial resources needed to recruit and test each participant, it may not be possible.
If your data collection procedures do not give you full control over your exact sample size, specify how you will decide when to terminate your data collection. Blinding Describe all variables you plan to manipulate and the levels or treatment arms of each variable. For observational studies and meta-analyses, simply state that this is not applicable.
Participants will be shown 5 pairs of shapes (copied from the O and R study). They will be instructed that in martian language one of those shapes is called x and the other y, and asked to tell the researcher which name ts each shape. Shapes are printed in pairs on a piece of paper-there are two versions with di erent orders of the shapes (shape x on the right, and y to the left or vice versa). The order of names given by the researcher is also randomized.
no le selected Describe each variable that you will measure. This will include outcome measures, as well as any predictors or covariates that you will measure. You do not need to include any variables that you plan on collecting if they are not going to be included in the con rmatory analyses of this study.
Possible covariates: ADOS results, AQ results, Wechsler results. Main measure: participants' responses in the task.

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If any measurements are going to be combined into an index (or even a mean), what measures will you use and how will they be combined? Include either a formula or a precise description of your method. If your are using a more complicated statistical method to combine measures (e.g. a factor analysis), you can note that here but describe the exact method in the analysis plan section.
For each participant I will create a mean of responses for the ve pairs of stimuli. Each pair will also be analyzed separately to see if the kiki/bouba e ect is present for every one of them. If it turns out that one or more stimuli pairs do not elicit the kiki/bouba e ect in the neurotypical group, the may be excluded from the analysis of the means.

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Please check one of the following statements Observational Study -Data is collected from study subjects that are not randomly assigned to a treatment. This includes surveys, "natural experiments," and regression discontinuity designs.
Blinding describes who is aware of the experimental manipulations within a study. Mark all that apply.
No blinding is involved in this study. Randomized order of names and randomized order of shapes What statistical model will you use to test each hypothesis? Please include the type of model (e.g. ANOVA, multiple regression, SEM, etc) and the speci cation of the model (this includes each variable that will be included as predictors, outcomes, or covariates). Please specify any interactions that will be tested and remember that any test not included here must be noted as an exploratory test in your nal article.
chi-square for the main analysis , correlations between test results and iq/ados no le selected If you plan on transforming, centering, recoding the data, or will require a coding scheme for categorical variables, please describe that process.
no If not speci ed previously, will you be conducting any con rmatory analyses to follow up on e ects in your statistical model, such as subgroup analyses, pairwise or complex contrasts, or follow-up tests from interactions? Remember that any analyses not speci ed in this research plan must be noted as exploratory.
not stated at this time