Descartes’ error”: evidences for the role of brain regions and their connections in introspective thoughts and self-identity

Abstract

Introduction: René Descartes was a French philosopher, considered the father of rationalism and one of the most important thinkers in history. Based on his methodical doubts’ technique, the author concluded that he exists as a thinking thing, that if “I think, therefore I am”. He establishes that he had no more doubts that he really existed as thought and as a body, however, he could not think that thought and body were two equal substances, since they had certain different properties, therefore, the author came to believe that mind and body were distinct substances. Since the 17th century, advances in neuroscience have helped to clarify which brain regions are involved in introspective and self-referential thinking. Methods: We reviewed through searches in PubMed, MEDLINE, SciELO and Scopus the brain regions involved in the self-referential and introspective thinking. Results: Recent studies show that self-referential and introspective thinking are located mainly in regions related especially to the Default Mode Network, mainly located in the frontal regions. Especially the “autobiographical self” shows greater activity in memory-related regions (hippocampus and posterior cingulate cortices), medial prefrontal cortex, and insula cortices, but the establishment of the “self” as the individual’s relationship to the world around it, uses regions related to exteroception, such as secondary and tertiary sensitive areas. For self-referenced thinking, there is greater engagement of the medial frontal cortex regions, more specifically in Brodmann’s area 10, and this structure is also related to the DMN. Conclusion: The advancement of neuroscience has allowed demonstrating that mental processes and thoughts happen as consequences of certain brain connections and processes. Thus, we ask poetic license to the great philosopher to say “the brain connections exist, therefore we think”.