The Complexity in Bilingual Code-Switching Research: A Systematic Review
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsComments for author File: 
Comments.pdf
Author Response
Reviewer 1:
Main comments: - Lines 445-447. The author(s) make the following statement: “In contrast, languages that are more distant from each other (e.g., English and Japanese) might lead to different optimization strategies, possibly with less code-switching but potentially more borrowing of specialized terms.” I am not sure this is the case. Is there literature or previous research that supports this statement?
Response: We rewrote this section in order to clarify the claims regarding the potential consequences of a larger language distance between languages on code-switching. This is now reflected in lines 451 to 456.
Minor comments: [Pertaining to grammar, capitalization, and formatting]
Response: Throughout the manuscript we have highlighted the minor details the reviewer pointed out to us. We thank the reviewer for their close reading of our manuscript and detailed feedback.
Reviewer 2 Report
Comments and Suggestions for AuthorsDear authors,
Find my comments and suggestions in the attached document.
Kindest regards.
Comments for author File: Comments.pdf
I have also made some comments on English. Some details like full stops missing, a standard for code-switching (sometimes hyphenated, sometimes not), and capital letters. I have marked most of them, but you should review all the code-switching cases. In general the English quality is very good.
Author Response
Reviewer 2:
“If it were 20 possible for a child or boy to live in two languages…” The idea of child or boy is weird, leave boy out, a child already involves boys and girls.
Response: Since this is a direct quote we abstain from making any modifications to keep it true to the source. For some context, in the 1800's “boy” could also refer to someone of any age as long as they were unmarried and still living in the family home, although typically the term was used to denote youth. We believe Laurie was implying that anyone who wasn't a full adult would be harmed by bilingualism.
In the manuscript, you used both, hyphenated and without a hyphen. I recommend keeping a standard, and honestly, I have always seen it hyphenated.
Response: Throughout the manuscript, as shown in highlighted text, code-switching is now hyphenated.
Throughout the literature this construct is referenced by a variety of 268 names (e.g., language switching, language mixing, or code-mixing) (Rodriguez-Fornells 269 et al., 2012). This is not so, there are many linguistics who differentiate between code-mixing, the mixing of two or more languages in a sentence, and code-switching, mixing two or more languages in the speech, for different reasons, to clarify, for instance. This is not exactly what code-mixing means. This is the definition you used in lines 307-311. But I have never seen cases in which code-switching is called code-mixing (the other way round, yes).
Response: We added a recommended citation to address the way in which the two terms code-switching and code-mixing have been used in the literature. (Starting at line 271)
Lines 271 to 274: Some studies focused on the frequency of code-switches, while others considered the different types of code-switches bilingual users engage in. Others account for the interactional contexts in which code-switching is present, and some utilize questions assessing various combinations of the three. Without any examples of the different types of code-switching, the sentence is vague. I recommend adding a theoretical framework explaining these concepts, without it, some readers cannot understand what you exactly mean by them. Later in the text you give these examples (line 313 on). However, the reader has been in contact with these terms since Table 1.
Response: The response and text added from the point above provides some context for variations in code-switching. Additionally, a more extensive delineation of the various forms of code-switching can be found in the sections immediately following line 280.
Style: "I need to finish my trabajo (work) by tomorrow." Here the foreign word should be italicized. "I was reading a fascinating book, y de repente, me di cuenta que casi eran las tres de la mañana (and suddenly I realized it was almost three AM)." Here the foreign words are not italicized and the translation, which does not necessarily need to be italicized.
Response: We italicized the foreign word and de-italicized the translation. This is now highlighted and changed in lines 321-323.
"Ayer fuí al mercado to buy 322 some frutas, but they were demasiado expensive. (I went to the market yesterday to buy some fruits but they were way too expensive)". I would contextualize a bit, for instance, this sentence would be okay in Miami, but it would sound weird in Spain, where bilinguals never densely mix English and Spanish, but we might densely mix Gallego and Spanish /Catalan and Spanish.
Response: We thank the reviewer for this suggestion. The contextual nature of the various forms of code-switching is a major point of the paper. The purpose of these sentences here is to simply give the reader an example of what these code-switches look like. We expand on the sociolinguistic influences on code-switching in the discussion.
Lines 371-373: Similar to broader cognitive work examining task switching, these studies (Beatty-Martínez et al., 2020; Jylkkä et al., 2020) focused on measures in terms of switch or mixing costs. In bilingualism work, both switching and 373 mixing costs refer to the cognitive costs associated with switching between two languages. Because the terms are not well established beforehand and authors use different terms, this manuscript is confusing at times. I insist on having the theoretical framework explaining all these terms and how they are being applied here. You might have to change some terms to adapt to your manuscript, as authors may use different terms to mean the same thing.
Response: We thank the reviewer for asking us to clarify these terms. We added text to clarify that switching costs and mixing costs specifically apply to the costs in an experimental paradigm. We also added the word block to emphasize the nature of this terminology specifically referring to the costs associated with experimental manipulation.
A switch cost is the specific cost of changing languages on a given trial, while mixing cost is the general cost associated with being in a context where 378 such changes can occur. For instance, a bilingual person might be asked to name pictures in only one language (single-language block) and then to name pictures by switching between two languages (mixed-language block) If the person is slower or makes more errors 381 in the mixed-language block, this could be attributed to the "mixing cost". Han et al. (2022)… Could you provide another example to explain the switch cost as well?
Response: We added an explanation for “switch cost” to help readers differentiate it from “mixing-cost”.
Line 397 ”… to mitigate the significant cognitive demands and performance impairments typically observed in controlled scenarios involving language switching and mixing.” Here again, you differentiate language switching and mixing, although previously you said that code-mixing was a synonym of codes-witching. Stick to one single definition.
Response: Clarified the use of terminology to refer to switching between languages instead of “language-switching or code-mixing”.
Line 652-654: They interpreted this to mean that at least in Montréal, bilingualism functions as a salient social identifier that signals group membership and cultivates the development of stronger ties to other bilinguals in their social network.” More connections like this one could be made for other examples.
Response: We thank the reviewer for this suggestion! We added another connection as requested on another study that utilized network approaches.
Reviewer 3 Report
Comments and Suggestions for AuthorsThis systematic review delves into the operationalization of bilingualism in studies investigating the correlation between bilingual code-switching experience and cognition. Guided by PRISMA principles, the analysis encompasses thirty-two studies, specifically targeting adult non-clinical samples. The review sheds light on the various aspects considered in measuring bilingualism and code-switching experience. The authors advocate for a broader approach, urging the incorporation of sociocultural factors and more sophisticated analytical modeling in bilingualism research to propel the field forward. Overall, this review stands as a welcomed addition to the existing literature, contributing to a deeper understanding of the complex relationship between bilingualism, bilingual code-switching experience, and cognition.
I would like to propose a suggestion that, in my opinion, could enhance the discussion and overall significance of the review. It is unclear whether the analysis amalgamated studies involving code-switching within the utterance (for ex. intra-clausal code-switching) with experimental studies where participants are instructed to switch languages upon encountering a cue, thereby inhibiting the use of the other language (usually referred to as language switching). A point worth contemplating is whether studies on language switching can offer valuable insights into the understanding of code-switching (see Gullberg et al. 2009). Given the focus on complexity in bilingual code-switching research, I believe this aspect deserves thoughtful reflection and inclusion in the discussion.
Additionally, please check the reference section for completeness as some references are missing from the reference list (e.g. Laurie 1890, Peal and Lamberts 1962).
References:
Gullberg, M., Indefrey, P., & Muysken, P. (2009). Research techniques for the study of code-switching. In The Cambridge handbook on linguistic code-switching (pp. 21-39). Cambridge University Press.
Author Response
Reviewer 3 Comments:
I would like to propose a suggestion that, in my opinion, could enhance the discussion and overall significance of the review. It is unclear whether the analysis amalgamated studies involving code-switching within the utterance (for ex. intra-clausal code-switching) with experimental studies where participants are instructed to switch languages upon encountering a cue, thereby inhibiting the use of the other language (usually referred to as language switching). A point worth contemplating is whether studies on language switching can offer valuable insights into the understanding of code-switching (see Gullberg et al. 2009). Given the focus on complexity in bilingual code-switching research, I believe this aspect deserves thoughtful reflection and inclusion in the discussion.
Response: We thank the reviewer for this suggestion. In conceptualizing our review we discussed this very question at length. For our systematic review, our main point of interest was to investigate the ways in which researchers were operationalizing naturalistic code-switching. This goal when enforced by the article selection criteria in the PRISMA methodology meant that any studies that experimentally manipulated code-switching but did not attempt to operationalize how bilinguals use their languages in their daily lives were not within the scope of our review. In our discussion we highlight the growing concern among researchers (Beatty-Martínez et al., 2018; Blanco-Elorrieta & Pylkkänen, 2018) that switch costs present in traditional experimental code-switching tasks might reflect task specific difficulties and not the intended language-switching abilities. Since we agree with the reviewer that there is a benefit to increased experimental control we also highlight studies in and outside of our review that are creating experimental tasks that more closely resemble the circumstances in which people switch between languages in their daily lives.
