Will better psychiatric treatments emerge from top‐down or bottom‐up neuroscientific studies of affect?

Cacioppo et al 1 discuss how the emerging social neuroscience perspective may promote understanding and treatment of psychiatric disorders. They argue that all these disorders are embedded within social structures that strongly influence our thoughts and feelings. This is true. Still, it remains ambiguous how top-down enculturated perspectives to human minds will yield fundamental insights to psychiatric therapeutics beyond what psychiatry has already achieved. Aside from debatable attractions of modern brain imaging, embraced finally by psychological sciences, how might social neuroscience provide new psychiatrically useful perspectives that are not already reasonably well developed in biological psychiatry? Certainly it is wonderful that social psychology is finally studying the brain, with many unique contributions, such as illumination of brain substrates of empathy (e.g., 2). Still, an enormous challenge for human social neuroscience is to provide new therapeutics. Another is for social and affective neurosciences to coordinate their efforts, especially better integration of top-down social and bottom-up neuroevolutionary perspectives. Such work remains rare. I was delighted that Cacioppo was among the first to adopt my 1998 text Affective Neuroscience: The Foundations of Human and Animal Emotions 3 for classroom use. That vision served as one springboard for his advocacy of “social neuroscience”, which followed historically upon “social psychophysiology” initiatives 4. But it would be useful to more fully harmonize top-down, human focused approaches with bottom-up cross-species affective neuroscience ones. Integration of knowledge bases is essential to minimize the likelihood of related approaches talking past each other, and promoting splintering that was common in 20th century psychology. How shall we integrate diverse neuroscience approaches to yield new psychiatric insights? Clearly, investigators of human and animal emotions need to seek unified research strategies, with neuroevolutionary issues being a centerpiece, while not emulating many flaws of modern evolutionary psychology, with speculations about the evolution of human cortico-cognitive tendencies, that remained unintegrated with cross-mammalian affective processes 5. Likewise, many issues that concern human social neuroscience are emergents of social learning, that remain tethered to cross-mammalian affective underpinnings. Unfortunately human social neuroscience has no substantive access to such issues without invasive brain research. How is this dilemma to be solved? I believe this question is critical for the impact that human social neuroscience can have on fundamental psychiatric issues. Novel psychiatric treatments cannot be found without a constitutive biopsychological understanding of core affective processes. This issue will require fuller cross-species integration, especially from neurosciences that are heavily invested in fundamental mammalian social emotional/motivational processes. Animal brain research is essential for clear visions of evolved origins of the human mind, since it provides access to primary-process brain-affective mechanisms upon which consciousness itself is still grounded 3,6. Top-down human approaches simply cannot achieve that with comparable scientific rigor. On the other hand, it may be wise to envision the socially-constructed cognitive subtleties of the human mind, that arose from the rapid evolutionary expansion of human neocortex, upon which learning, rather than evolutionary modularization, “stamps” the diverse functional specializations 7. Thus, to advance psychiatric thought, a key issue for human social and cognitive neurosciences should be (without resurrecting an outdated nature-nurture debate): to what extent are the adult neocortical functions of human beings due to evolutionary selection as opposed to social construction? The subcortical instinctual functions of mammalian brains are clearly inherited. The local regional circuitry of neocortical columns is also certainly constrained by strong evolutionary underpinnings, as are many of the looping intracortical connections, but this does not mean that either prescribes functions as opposed to offering potentialities (depending on subcortical inputs). Clearly, most neocortical functions are developmentally rather than evolutionarily programmed 7. This has profound implications for the fecundity of a human-oriented social neuroscience that has little access to fundamental issues. All mammals are close evolutionary relatives with regard to subcortical affect and motivation networks and their vast mind-supporting, consciousness-creating neural networks and chemistries. Although abundant genetic polymorphisms code brain chemistries – from transmitters to receptors to all the intermediate neuronal housekeeping processes – the bottom line is simple: we humans are not special in the types and neurogeographical distributions of our genetically selected brain circuits and their neural chemistries, an understanding of which will lead the way to new psychiatric therapeutics. For human social neuroscience to have substantial impact on human psychiatric therapeutics, it needs insights from affective neuroscience approaches that can access the actual neural mechanisms of the affective mind. For instance, the fundamental psychological-pain mechanisms that mediate separation-distress in mammals are clearly self-similar 3, potentially allowing us better medical treatments of depression than behavioral and cognitive approaches of the past have provided (e.g., 8-11). So, when we speak about human loneliness and social bonding, our understanding of the underlying raw affects may be illuminated more by animal studies than by human ones 12,13, a key strategic issue social neuroscience would be wise to consider. I look forward to a human social neuroscience that becomes fully integrated with the affective neurosciences that have long dealt with issues of psychiatric interest. We now need better two-way communication among the human and animal neurosciences. Our own efforts to link cross-species affective neuroscience findings to fundamental human psychiatric issues can be found in Panksepp 3 and Panksepp and Biven 14.