Looking times for A) iBEATs and B) iBREATH.

Note. Looking times for the A) iBEATs and B) iBREATH tasks. In both tasks, 9-month-old infants looked significantly longer at stimuli presented synchronously to their own physiological signals. Black dots refer to the group mean. Black bars refer to the standard error of the mean. Grey lines and colorful dots refer to individual mean looking times per condition and infant.

Results from the MEGA analysis for A) iBEATs and B) iBREATH.

Note. Plot of difference scores computed as mean synchronous looking times minus mean asynchronous looking times per individual for each age group, as well as the combined sample. Red dots refer to mean effects for the respective analysis as described above, red bars refer to 95% confidence/credible intervals. Dashed line indicates a difference of 0. For 3, 9, and 18 months age groups our preregistered analysis is plotted. For the combined sample we computed a linear mixed model using lme4 for visualization purposes as results from a mixed model with a beta error distribution cannot easily be transformed back to the original scale.

Full-null model comparison for the iBEATs model.

Results for the MEGA analysis of the iBEATs data.

Full-null model comparison for the iBREATH model.

Results for the MEGA analysis of the iBREATH data.

Results for the MEGA analysis of the iBREATH data excluding the 18-month-olds.

Relationship between iBEATs and iBREATH using a combined sample.

Note. Histogram with plotted line for individual performance on iBEATs and iBREATH using a beta regression. Following Maister et al. (2017), individual difference scores were computed as proportion of absolute difference between synchronous and asynchronous trials.

Exploratory analysis for age effect.

Note. Absolute proportional scores for A) iBEATs and B) iBREATH plotted for each age group. Red dots refer to group means, and colorful dots to individual means.

MEGA analysis for the relationship between iBEATs and iBREATH.

Change in absolute proportional scores across age groups for the iBEATs.

Change in absolute proportional scores across age groups for the iBREATH.

Specification Curve Analysis for the A) iBEATs and B) iBREATH task.

Note. Specification curve analysis plotting standardized beta regression coefficients (y-axis) and number of analysis (x-axis) for A) iBEATs and B) iBREATH. Number of analysis (x-axis) are ordered increasing from lowest to highest standardized beta regression coefficient. Blue color indicates a significant effect (p <. 05) for a mean synchronous preference, red color indicates a significant effect (p < .05) for a mean asynchronous preference, and grey indicates a non-significant outcome

Number of significant results for specifications for iBEATs and iBREATH

Descriptive information for number of trials

Analytical decisions for the iBEATs.

Analytical decisions for the iBREATH.

Inference of the Specification Curve Analysis

Specification Curve Analysis for the iBEATs.

Note. Descriptive results from the specification curve analysis for the iBEATs task. Blue coloring in A) and B) refers to a significant result for a mean synchronous preference, while red color indicates to a significant result for a mean asynchronous preference (p < .05) for the specification and test. In A) standardized beta regression estimates are plotted. In B) an overview for a range of analytical choices is given. In C) analytical choices are further decomposed.

Specification Curve Analysis for the iBREATH.

Note. Descriptive results from the specification curve analysis for the iBREATH task. Blue coloring in A) and B) refers to a significant result for a mean synchronous preference, while red color indicates to a significant result for a mean asynchronous preference (p < .05) for the specification and test. In A) standardized beta regression estimates are plotted. In B) an overview for a range of analytical choices is given. In C) analytical choices are further decomposed.

Simulating data frames for sample sizes from 15 to 125 building up on the iBEATs data from the 9-month-olds.

Note. Results from the simulations. In A) mean effects and 95% confidence intervals are plotted for the different sample sizes. Red color indicates a significant effect, while blue indicates a non-significant result. In B) the percent of significant results are plotted with a fitted line.

Looking times for slow and fast asynchronous trials