In this chapter, the author goes deeper into the neurolinguistic aspects of simultaneous interpreting. Simultaneous interpreting so as consecutive interpreting are very complex linguistic tasks. These tasks involve linguistic and cognitive activities, but also psychological and neuropsychological functions. The author describes the cerebral activity while interpreting, but she also discusses bilingualism and multilingualism and their effects on the brain. She enters into the functioning of the long-term and short-term memory and discusses some neuropsychological aspects.