The “code-switching issue”: transition from (socio)linguistic to cognitive research

This review investigates the complex dynamics of code-switching (CS), the spontaneous alternation between languages within a conversation, particularly its implications for cognitive processes like executive functions (EFs). Analysing post-2015 studies, it critically assesses 23 experiments. Through stringent criteria and comprehensive search strategies, the review identifies factors influencing CS types and their impact on cognition, highlighting methodological inconsistencies and confounds. It highlights the evolving perspectives on CS, ranging from pragmatic approaches emphasizing communicative functions to structural analyses focusing on linguistic constraints. It underscores the importance of considering factors such as language competence, typological proximity and cognitive processes in understanding CS behaviour. It emphasizes the need for precise CS typology assessment to understand the complex link between CS behaviour and cognitive functioning, bridging linguistic and cognitive domains. This review contributes to clarifying inconsistencies in CS research methodology and findings, aiming to elucidate the factors influencing CS types and their implications for cognition.