Testing the Bilingual Cognitive Advantage in Toddlers Using the Early Executive Functions Questionnaire

Round 1

Reviewer 1 Report

Review Testing the bilingual cognitive advantage in toddlers using the

Early Executive Functions Questionnaire

 

This paper reports about a study with multilingual and monolingual toddlers. It was investigated whether multilingual toddlers have better executive functioning skills than monolinguals, and whether a possible advantage was dependent on the amount of language exposure children received. Children performed 4 executive functioning tasks (administered by parents) and parents filled in a questionnaire about their child’s executive functioning skills. Although this paper is generally well written, the research method seems less appropriate. Furthermore, the way variables are operationalised could be improved. My comments appear below, in order of appearance in the manuscript.

 

Is attentional inhibition the same as cold inhibition, or is it a specific form of inhibition?

 

although this effect may be partially explained by socioeco- 62 nomic status à as in, bilinguals coming from higher SES backgrounds than monolinguals?

 

“Supporting this idea, a longitudinal study found 175 that bilingual toddlers who acquired more TEs between the ages of 24 and 31 months 176 had greater inhibition skills by 31 months than those who acquired fewer TEs during 177 that period (Crivello et al. 2016). Thus, gains in attentional inhibition occur when bilin- 178 guals switch between two language systems more frequently” à I am not sure whether this reasoning holds. In theory, a child could acquire a large number of TEs without frequently switching between languages. Such a situation would maybe occur if a child only switches between languages once a day, and still has a similar amount of input in both languages. And if the reasoning holds, isn’t it language switching instead of number of TEs that accounts for switching/inhibition abilities?

 

“greater non-dominant language exposure would exhibit stronger inhibitory control” à If the exposure to the non-dominant language is greater, wouldn’t that imply that children receive more balanced exposure, and therefore maybe also more balanced language proficiency? I think the manuscript could improve in using similar terminology everywhere. Now “more translation equivalents”, “more balanced language exposure”, “greater non-dominant language exposure” are used intertwined, and that is at some points confusing.

 

To test our third hypothesis, we created a sub-sample of 31 French-English multilingual participants from our overall sample (16 female, Mage = 23.58 months). à which participants were excluded then? Or what were the criteria for participants to be included in this subgroup?

 

Why create subgroups of monolingual and multilingual participants instead of using a continuum of bilingualism, ranging from 0% exposure to another language to the max of exposure?

 

The experimental tasks were performed by parents, mostly with attributes found in their home. Though I can see the benefits of this method (less invasive for young children), this means that the researcher has less control over it. Was it checked whether the parents correctly performed the tasks and used adequate materials? For example by videos? Otherwise this method may not be that valid, especially since the multilingual participants’ parents had much more education and may therefore be more familiar with these kinds of experiments than the monolingual participants’ parents. For all parents holds that they may have helped their children. Although a testing session led by the researcher (or a trained assistant) would be preferable, the authors do not even reflect on the way tasks were assessed in the Discussion.

 

3.2.6 Overall results à I think discussing the hypotheses belongs to the Discussion section. But it is not quite clear to me what kind of analyses were done. The authors first report on analyses, then go on to “overall results” in which they discuss whether their hypotheses were confirmed or not. Then, under 3.3.1. the authors start describing a statistical model, without mentioning what kind of analyses were performed and with what reason (although later in the text they mention linear regression analyses).

 

 

 

 

 

Author Response

Please see attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Review for Languages (1593175): Testing the bilingual cognitive advantage in toddlers using the Early Executive Functions Questionnaire

The paper reports a study on EF differences between monolingual and multilingual toddlers using multilingualism on a continuous scale and as a dichotomous variable (and thus taking into account the recent call for multilingual populations needing to be assessed on a continuum of language experiences instead of the previously used monolingual-multilingual dichotomy). Multilingual toddlers with more non-dominant language exposure and who had acquired more translation equivalents across their languages were expected to show enhanced development in specific EF components. Toddlers’ parents filled in a parent report which only yielded differences between groups on response inhibition, specifically for the multilingual toddlers with more non-dominant language exposure. Translation equivalents and EF components did not show any association. The authors interpreted their data as confirming a domain-specific cognitive advantage for multilinguals.

Overall, I found this paper to be well written and the novel approach here was to use parental reports to assess hot EF. Below are my comments:

Given the ongoing discussion in the field about mixed findings in the multilingualism effects on EF domain, the recent paper by Bialystok and Craik (2022) may need to be reviewed as well as it offers a fresh view on which EF effects could be expected for multilinguals based on their language experience.

line 43 ff.: For more nuance, the authors should also address the fact that there is low convergent validity across EF tasks tapping inhibitory control (see Poarch & Van Hell, 2019; Poarch & Krott, 2019).

line 138: Assuming that differences found in previous literature “may be due to impure assessments” is a stretch – one could also argue that those studies that found no differences were using “impure assessments”.

line 151: For a discussion of the mixed evidence, see Poarch & Krott (2019)

line 262: What guided the authors to use a 20% exposure threshold to discern between monolinguals and multilinguals?

line 269: Which measure was used to assess cognate and semi-cognate status?

line 401 ff.: for all the results, I find displaying the means, SDs, and CI as MMonolingual and MMulitilingual etc. to be cumbersome to read and the words are unnecessarily repeated.

line 423: I may be reading this incorrectly, but it should be .06 lower, not .06 higher.

line 430: similar issue

Table 4: I do wonder whether, since all the results are non-significant, they need to be reported in such detail in this table.

line 565: The Costa et al. (2006) paper is a review and does not focus on EF specifically. For work using. for example, the ANT with children, see Poarch & Van Hell (2012.

Minor textual issues:-

line 10: individual –> individuals

line 10: treat –> treats

Author Response

Please see attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The manuscript has greatly improved. The authors responded to all my comments. I have only one final comment: 

 

In their rebuttal letter, the authors explain why they do not use a continuum (because of the multilingual instead of bilingual participants). Yet, in the abstract they state “both when dichotomizing multilingualism and assessing it on a continuum”. This is confusing. Same on page 11: “As the EEFQ has not been previously used to investigate the bilingual cognitive advantage, using a categorical method, in addition to a continuous approach, allows the present findings to be more easily compared to the previous literature, which has largely used a categorical variable (see 429

Adesope et al., 2010; Lowe et al., 2021).” And in the first paragraph of the discussion: “Additionally, by adopting an approach that treats bilingualism on a continuum, it was expected that participants with greater non-dominant language exposure would show higher response inhibition, attentional flexibility, and regulation.”

 

Author Response

We apologize for any confusion. We use both a dichotomous and continuous approach to assess whether greater non-dominant language exposure is associated with executive functioning.

In the Language Group Differences section (page 11), we applied the dichotomous approach by splitting the sample into two groups: monolinguals and multilinguals. We defined the language exposure requirements for these groups on page 7. Using a series of ANCOVAs we compared the executive functioning between the monolingual and multilingual groups.

In the Language Exposure Effect section (renamed Language Exposure on a Continuum, page 13), we applied the continuous approach. Here, we included the entire sample in a series of linear regressions that assessed how non-dominant language exposure (ranging from 0% to 54.45%, as specified in Table 1) predicts each executive function.

We changed the title of section 3.3 to “Language Exposure on a Continuum” and added an additional sentence to clarify that a continuous approach was used here (line 510).