Revisiting a 150-year-old conundrum on the role of Broca’s area in language processing: Embracing expected and unexpected results

In the current topic we would like to address a longstanding conundrum in language sciences on the role that Broca’s area plays in language processing. This area was initially viewed as the seat of language production, later it became known as the hub for syntax and more recent proposals view it as a non-critical language region providing domain-general support for language processing. The controversy is partly due to evolving methods that increasingly allow us to get more accurate temporal and spatial information about the role that Broca’s area plays in language and cognition, forcing us to re-evaluate previous findings. Partly obfuscating the results is the lack of consensus regarding the anatomical definition of Broca’s area in the field, with a functional definition often implicitly assumed. Further, another contributing factor to the existing controversy, is the preponderance of positive findings skewing the current set of knowledge in science at large, and researchers being hesitant to report null or controversial results that undermine existing theories. In language sciences, many well-designed studies not showing the expected effect are never published despite a solid methodology and a strong theoretical background. Underreporting of negative and unexpected results introduces bias into the meta-analysis, engendering possibly inaccurate theories and misleading clinical guidance.

The goal of this Research Topic is to contribute to the longstanding debate surrounding the role of Broca’s area in language. We aim to accomplish this by explicitly including null and unexpected alongside expected results from language studies to provide a more comprehensive picture on the specific role (or lack thereof) of Broca’s region (defined as pars opercularis and pars triangularis, or BA 44 & 45) in language processing. Here we aim to provide a forum for sharing and discussing both positive, null, and unexpected findings using varied methods with the aim of forming a comprehensive understanding of the functional contributions of Broca’s area. By shifting the focus away from the significance of the results and instead refocusing it on the quality of the study design and rigor of execution, we as a field can be more knowledgeable of current developments. Embracing null or unexpected results from well-designed studies if interpreted correctly can convey critical information which can help scientists refine language theories and enable them to proactively modify their experiments considering previous null findings, helping the field to move forward faster.

The scope of this Research Topic is to provide a forum for sharing and discussing well-designed studies with both positive and negative findings investigating the functional role of Broca’s area (defined as pars opercularis and pars triangularis, or BA 44 & 45) in language processing. Papers can include different methods of behavioral and brain measurements in diverse populations. The manuscripts solicited in this issue are required to have well-designed tasks, a solid methodology, sufficient power, and adequate statistical models (for example, Bayesian modeling to assess the likelihood of absence of differences), along with clearly anatomically defining Broca’s area. Authors should highlight how the presented findings add to the ongoing debate on the functionality of Broca’s area, advance contemporary models of language processing and how future studies can expand on their work. We welcome submissions that include the following, and strongly encourage submissions related to the latter two bullet points:
• Positive findings (i.e., role of Broca’s area in an expected language ability ascertained)
• Null/negative findings (no relationship between Broca’s area and linguistic processing detected)
• Unexpected findings (i.e., Broca’s area was found to contribute to an unexpected ability).