'Interoceptive Sensitivity in 9-month-old Infants' (AsPredicted #46693)
Author(s) This pre-registration is currently anonymous to enable blind peer-review. It has 5 authors.
Pre-registered on 2020/08/25 - 07:56 AM (PT)
1) Have any data been collected for this study already? No, no data have been collected for this study yet.
2) What's the main question being asked or hypothesis being tested in this study? In this study, we will investigate cardiac and respiratory interoceptive sensitivity of infants at 9 months of age. We expect that interoceptive sensitivity in the cardiac domain will correlate with interoceptive sensitivity in the respiratory domain in 9-month-old infants.
3) Describe the key dependent variable(s) specifying how they will be measured. In the first experiment, we will examine the behavioral markers of cardiac interoceptive sensitivity in infants by using a recently developed innovative paradigm named the Infant Heartbeat Task (i.e. iBEAT) (Maister et al., 2017). This task measures infants’ sensitivity to their own heartbeats as an indication of interoception in preverbal infants. In this task, infant-friendly images (e.g. stars or clouds with faces), which move either in synchrony or out of synchrony (±10% faster or slower) with the infant’s own heartbeat, will be sequentially presented to the infant while their total looking time to each stimulus is measured.
In the second experiment, we will investigate the interoceptive sensitivity of the infant based on respiratory rate measures using the iBREATH paradigm that will be developed by us. This approach will allow us to validate the interoceptive sensitivity assessments in infants and extend the previous research on cardiac measurements. Similar to the iBEAT paradigm, we will present infants with animated characters on the screen that expand in synchrony or out of synchrony with their respiratory rate, while we measure their total looking times at the images.
We will calculate a discrimination score as the absolute proportion of the difference between looking times in the synchronous and asynchronous trials separate for cardiac and respiratory interoception tasks to later correlate the two measures.
4) How many and which conditions will participants be assigned to? In a within subjects design, infants will observe synchronous and asynchronous trials, in which the images on the screen move either in synch or out of synch (respectively) with their heartbeat and respiration. The same infant will perform both cardiac and respiratory interoception tasks.
5) Specify exactly which analyses you will conduct to examine the main question/hypothesis. In both experiments, we will compare mean looking times to synchronous and asynchronous trials with paired sample t-tests. All tests will be compared against a two-tailed p<0.05 level of significance. We will run Pearson correlations using the difference scores for cardiac and respiratory interoception tasks to examine the relationship between them.
6) Describe exactly how outliers will be defined and handled, and your precise rule(s) for excluding observations. We will include trials in which no movement artifacts in electrocardiogram and respiration recordings were observed. Trials in which looking time values are more than two standard deviations away from group mean for that condition will be discarded. Similar to the Maister et al. (2017) study, we will exclude infants who do not provide with a minimum of eight trials in total (four in each condition) in the iBEAT task. Because the trials in the iBREATH task are much longer (due to respiration being slower than heart rate), we will include infants who provide a minimum of four trials in total (two per condition).
7) How many observations will be collected or what will determine sample size? No need to justify decision, but be precise about exactly how the number will be determined. We aim to test 90 infants. Given the recent developments on Covid-19 pandemic, we might not be able to reach this goal. In that case, we will stop testing by May 2021.
8) Anything else you would like to pre-register? (e.g., secondary analyses, variables collected for exploratory purposes, unusual analyses planned?) We plan to measure cardio-respiratory coupling in infants during a resting state phase where infants watch an infant-friendly video in between the two tasks where we measure their heart rate and respiration at the same time.
Depending on the developments regarding Covid-19 pandemic, we plan to follow up the infants longitudinally and repeat all measurements when the infants are at 18 months of age.
For supplementary information, the mothers will be asked to fill in questionnaires about the infant’s social-emotional development, temperament and relation quality. Specifically, we will use the following questionnaires: 1) The very short form of the Infant Behaviour Questionnaire-Revised (IBQ-R VSF 2) Barkin Index of Maternal Functioning 3) The Parental Reflective Functioning Questionnaire (PRFQ) 4) The Positive and Negative Affect Schedule (PANAS) 5) Milestones Of Normal Development in Early Years (MONDEY).
We also plan to investigate interoceptive sensitivity of the infants’ mothers by examining their cardiac interoceptive sensitivity. We predict that infants of mothers with high cardiac interoceptive sensitivity will perform better in the interoceptive sensitivity assessments as compared to the infants of mothers with low interoceptive sensitivity. We will measure cardiac interoceptive sensitivity of the mothers using well-established behavioral paradigms, namely Heart Beat Discrimination Task (Katkin et al., 1983) and Heart Beat Tracking Task (Schandry, 1981). Mothers will also fill in the Multidimensional Assessment of Interoceptive Awareness (MAIA-2) questionnaire.
In case of a strong relation between infants’ performance in the iBEAT and the iBREATH tasks, we will integrate both measures into a combined interoceptive sensitivity score. We will then run Pearson correlation analyses to determine whether mothers’ interception correlates with their infants’ interoceptive sensitivity.
Data collection for this study will be embedded in a larger study with the same age group.
