The brain uses a mental language to represent and organize complex ideas and concepts. This mental language is thought to be distinct from natural languages like English or Spanish, and it is believed to be the medium through which we think and process information. According to the LOTH, the structure and content of this mental language are shaped by the structure and content of the natural languages that we learn, but it is not identical to any one natural language. Instead, it is thought to be a universal language that is used by all humans to represent and process complex ideas. Link: https://plato.stanford.edu/entries/language-thought/