Neuroethological Perspectives on the Human Brain: From the Expression of Emotions to Intentional Signing and Speech

Abstract

While pondering the theme of this workshop, it occurred to me that most neuroscientists, regardless of whether they work at the molecular, the systemic, or any other level of central nervous system functioning, ultimately want to contribute to our understanding of the human brain. This attempt has produced certain successes at all levels when particular physical or medical questions have been addressed. But if one regards the human brain as the substrate of human behavior, the matter becomes extremely complex. In fact, rapidly accumulating knowledge on the molecular and cellular levels presents an almost hopeless perspective in regard to the possibility of explaining an organism’s behavior even when one deals with so-called simple systems, such as that characterizing worms. Without disregarding the relevance of the bottom-up approach in molecular biology or its many success stories in recent decades, nevertheless, if one’s goal is to explain behavior via brain mechanisms, one’s approach must change to that of a top-down analysis. With this approach, one starts with the behavior of an organism and then proceeds from the analysis of this behavior to an examination of the neural substrates that bring about a specific part of behavior, for example, eating behavior. This approach is taken in neuroethology (which does not exclude molecular methods, where applicable). Behaviors that are specific for a certain species or typical for a genus or a family or an order (such as the primates) are first analyzed, and then the causal relationships between such behaviors and their neural substrates are investigated.