Study title

This data collection entails a range of data collected from monolingual and bi/multilingual adult participants living in and around Birmingham, United Kingdom. This includes questionnaire data (mainly from the Language and Social Background questionnaire), EEG data collected during the execution of cognitive control tasks (Flanker task, Simon task, Colour-Shape switching task, Number-letter task) and structural MRI brain scans. For the majority of participants all type of data is available.The number of children learning a second language at school in the UK has dramatically decreased in the past 10 years, even though learning a second language has many benefits. It broadens understanding of different cultures, improves literacy and employability, and importantly, may also be good for the brain. Being bilingual appears to have a positive effect on a collection of high level cognitive abilities, often referred to as executive functions such as response inhibition and task switching. Speaking another language might also slow down cognitive decline by delaying the onset of dementia. The reason for these effects is thought to be the constant inhibition of one language when speaking the other and frequent language switches. Moreover, it is known that poor executive functions are linked to social problems including antisocial behaviour or addiction. Improving executive functions via language learning might potentially lessen such problems. Despite a growing and large body of evidence in favour of executive advantages, some studies have not been able to replicate the findings. One often suggested explanation for these inconsistencies is the heterogeneity of the bilingual population. Bilingual speakers differ with respect to when they started to learn their second language, how fluently they speak it and how often they use each language. All these factors have been found to be independently related to executive function abilities, but no study to date has systematically...