Bilingual education has witnessed a major shift towards mixing two languages in the classroom. However, adequate methods taking into account the needs of today’s highly multicultural world require scientific testing. Translanguaging is a method of learning in which students produce an output of their learning in a language different to that of instruction. So far, insights into the potential benefits of this method have been exclusively qualitative. The aim of this thesis was to quantify the benefits of translanguaging for new knowledge acquisition. In the main experiment (Chapter 4) I have found neuroscientific evidence for facilitated access to existing semantic representations for items used in learning mediated by translanguaging as compared to control items presented in a monolingual learning context. Participants were tested using a picture-picture priming paradigm after a learning phase involving either English or a code-switch between English and Welsh simultaneous with a switch between reading and speaking. Beyond the expected effect of semantic relatedness on the mean N400 amplitude, well known to index semantic processing effort (Kutas and Hillyard, 1980), a striking main effect of translanguaging on the same N400 was found, suggesting that relevant semantic representations had become selectively more accessible in long-term memory. Moreover, this effect could still be measured 2 to 4 weeks later without participant training. In chapters 5 and 6, I have set out to test the two components of translanguaging separately in order to determine the contribution to the overall effect of code-switching on one hand and comprehension-to-production on another. Chapter 5 focuses on the automaticity of semantic priming and the potential impact of code-switching on the N400 in Welsh-English bilinguals. Chapter 6 focuses on the effects of the comprehension-to-production switch on the N400 in Basque-Spanish bilinguals.