Attrition rate in infant fNIRS research: A meta‐analysis

Abstract

Understanding the trends and predictors of attrition rate, or the proportion of collected data that is excluded from the final analyses, is important for accurate research planning, assessing data integrity, and ensuring generalizability. In this pre‐registered meta‐analysis, we reviewed 182 publications in infant (0–24 months) functional near‐infrared spectroscopy (fNIRS) research published from 1998 to April 9, 2020, and investigated the trends and predictors of attrition. The average attrition rate was 34.23% among 272 experiments across all 182 publications. Among a subset of 136 experiments that reported the specific reasons for subject exclusion, 21.50% of the attrition was infant‐driven, while 14.21% was signal‐driven. Subject characteristics (e.g., age) and study design (e.g., fNIRS cap configuration, block/trial design, and stimulus type) predicted the total and subject‐driven attrition rates, suggesting that modifying the recruitment pool or the study design can meaningfully reduce the attrition rate in infant fNIRS research. Based on the findings, we established guidelines for reporting the attrition rate for scientific transparency and made recommendations to minimize the attrition rates. This research can facilitate developmental cognitive neuroscientists in their quest toward increasingly rigorous and representative research.

Frontal asymmetry assessed in infancy using functional near‐infrared spectroscopy is associated with emotional and behavioral problems in early childhood

“…Seventy‐three additional children participated in both the infant and 5‐year testing sessions but were excluded from the present analyses because (a) they refused to wear the fNIRS cap ( n = 18), (b) their cap deviated beyond 1.5 cm from the correct placement ( n = 16), (c) equipment failed ( n = 6), (d) they failed to reach our pre‐determined looking criterion ( n = 11), or (e) channels in areas of interest did not pass quality thresholds applied during pre‐processing ( n = 22). This rejection criterion and attrition rate are similar to those in other infant fNIRS studies (Baek et al, 2021; Bayet et al, 2021; Farris et al, 2022; Filippetti et al, 2014; Kelsey et al, 2019, 2021; Lloyd‐Fox et al, 2015). As displayed in Table 1, the final analytic sample was predominately Non‐Hispanic White, and parents were highly educated.…”

Using functional near-infrared spectroscopy to study the early developing brain: future directions and new challenges

“… 88 , 89 To date, very few studies have carried out meta-analyses on developmental fNIRS data. 5 , 90 , 91 These studies suggest that at least some of the published fNIRS results are robust to replication and have small-to-moderate effect sizes, which is typical of developmental studies conducted with other methods. 88 Further studies will be needed in the future to systematically assess the replicability and effect sizes of key findings in the developmental fNIRS literature.…”

“…Meta-analyses have been successfully conducted over behavioral data in developmental populations 88 , 89 . To date, very few studies have carried out meta-analyses on developmental fNIRS data 5 , 90 , 91 . These studies suggest that at least some of the published fNIRS results are robust to replication and have small-to-moderate effect sizes, which is typical of developmental studies conducted with other methods 88 .…”

“…16 However, other phenomena, e.g., those that are inherently multimodal, multidimensional, or dynamic, may only be partially explored in the restricted context of a laboratory, impeding our full understanding of the research questions posed. For instance, in social cognition, a central theme in developmental psychology and an area of exponential growth in infant fNIRS, 5 infants' social skills have classically been assessed using static pictures or video stimuli of social signals to better control the experimental contrasts under investigation. However, research has shown the critical role of live social stimuli in infants, 17 as exemplified by the phenomenon "video deficit," whereby infants tend to show difficulties in learning or performing via unidirectional, nonlive video stimuli/presentations.…”

“…In the two and a half decades, since its first use with infants, fNIRS technology, experimental methods, and data analysis techniques have evolved considerably 2 – 4 to meet the special needs and challenges of developmental neuroimaging. As a result, developmental fNIRS research is growing exponentially 5 ( Fig. 1 ).…”