Talking therapy: A commentary on "Revisiting the left convexity hypothesis: changes in the mental apparatus after left dorso-medial prefrontal damage” by Salas & Yuen

Salas and Yuen’s reappraisal of Kaplan-Solms and Solms’ [2000. Clinical studies in neuro-psychoanalysis. Introduction to a depth neuropsychology. London, UK: Karnac Books] classic text revisits the left convexity hypothesis, further developing our understanding of mental changes associated with damage to the left dorso-medial prefrontal region. Language, including inner speech, is an important general factor in models of human behavior after brain damage, irrespective of whether a particular model’s primary focus is on biological, psychological, environmental, or other factors. The “currency” of psychological therapy is primarily language-based. For this reason, further refining our understanding of mental changes, including inner speech after brain injury, is of course very important. But there is also a more philosophical question pertaining to the whole endeavor of research and the production of knowledge. Why do we develop theories, do research? Research has many “currencies,” some very explicit, such as citations, impact factors, and so forth. And then, there is also the almost implicit crucial currency, perhaps mirroring inner speech, of translation, or the potential for our research to inform the work we do with our patients. Language, and in particular patients’ inner speech, is fundamental to psychotherapeutic work with brain-injured patients. It is here where Salas and Yuen’s paper may possibly prove to make the most important contribution.