Walter J. Freeman (1927–2016) was an influential American neuroscientist who developed a unique way of interpreting brain processes, perception, cognition, and intentionality. He was born in 1927 in Washington DC, received an M.D. from Yale University in 1954, and completed a postdoctoral training in neurophysiology at the University of California, Los Angeles, in l959. In the same year he joined the faculty of University of California at Berkeley, which started his unparalleled career there as a professor of neurobiology for 57 years, until his death in his Berkeley home on 24 April 2016.
The main objective of this special issue of JCS is to give a broad overview of Walter Freeman’s research, theories, and results, as it has developed over the more than half a century he was active as a neuroscientist. The focus is on neural processes at different organizational scales, and on the interrelationship between these levels and processes, and their relation to cognition and consciousness.
A number of invited authors, who have all worked closely with Walter Freeman and/or have related their own work to his, are here giving a close-up account of their scientific and personal relation with Freeman. In total, there are fourteen papers of various lengths and scope, written by eighteen authors, coming from different fields of science; from physics and mathematics to neuroscience, psychology, and philosophy — and also from different parts of the world: from Japan and China in the East, from Australia and New Zealand, from various countries in Europe, and, of course, from different parts of the US. The authors have chosen their topics freely, given the overall scope and objectives of this issue, and some of them also reflect on the impact of Freeman’s work, and where it might take science in the future.
The first ‘introductory’ paper is a multi-author contribution by Steven Bressler, Leslie Kay, Robert Kozma, Hans Liljenström, and Giuseppe Vitiello. It summarizes the last 25 years of Freeman’s work, divided into five key areas, from the physiology of sensory processing, to cognitive functions, to modelling of the action–perception cycle, to phase transitions and quantum field theory, and finally to intentionality and consciousness. Most of these topics are expanded upon and dealt with further in the other articles of this issue.
The following thirteen contributions have been grouped, somewhat arbitrarily, under four headings, although most of them deal with Freeman’s neurodynamics and its role for cognition and/or consciousness. Still, the emphasis and style is quite variable in the different papers.
Under the first heading, there is a group of three shorter papers, by Hermann Haken, Harald Atmanspacher, and Bernard Baars, giving personal reflections on their relations with Walter Freeman and his work, stretching over several decades. Haken takes his starting point from his general theory of Synergetics, which in interaction with Freeman developed into a more special theory of brain dynamics. How meaning is created by the brain is central to Freeman’s research, and is related to the idea of pragmatic information, which Atmanspacher developed and discusses in his paper. Baars, in his paper, focuses on Freeman’s work with animals and reflects upon the need for an increasingly humane treatment of animals, as we recognize conscious experience like pain in more and more species. While each of these three papers is rather short, the authors manage to capture essential aspects of Freeman’s work, including his EEG recordings, the neurodynamics, the action–perception cycle, and consciousness. At the same time, they all give a nice glimpse of the personality of Walter Freeman, which we learn about further in the following contributions.
Under the second heading, Physiological Perspectives, the contributions by Leslie Kay, Michael Mannino and Steven Bressler, as well as by James Wright and Paul Bourke are found. These three papers are centred around the physiological experiments carried out by the authors, where Kay and Bressler actually worked in Freeman’s lab, in different periods. Kay gives here a nice historical account of both Freeman’s experimental and theoretical work on the olfactory system, and how that work has carried over to her own research and outlook, where she still often asks herself the question, ‘What did Walter say?’. Kay’s paper ends with several open questions with regard to olfaction, where more knowledge and modern tools in computational neuroscience and neurophysiology should be able to lead to deeper understanding. Mannino and Bressler also refer to the early work of Freeman, but relate his neurodynamics to Scott Kelso’s theory of metastability in coordination dynamics (Kelso being a colleague of the two authors at the Center for Complex Systems, FAU). Bressler, having worked with both Freeman and Kelso, bridges beautifully the theories of the two, where state transitions, attractor dynamics, and circular causality are central. Finally, in this set of papers, Wright and Bourke set out to unify anatomical order and neural dynamics. The key here is synchronous gamma oscillations, which structures cortical networks and provides an ‘anatomy of cognition’. The authors also highlight differences between some of the theoretical work that has been developed based on Freeman’s research, some of which are discussed in this issue, and the challenge to compare and perhaps integrate them.
The third set of papers, under the heading Mathematical and Physical Perspectives, are more theoretical than the previous three papers, but are nevertheless based on work close to Walter Freeman’s experimental results, as well as his theoretical analysis and interpretation. The authors here are Ichiro Tsuda, Robert Kozma and Joshua Davis, and Giuseppe Vitiello. Tsuda, himself a physicist and mathematician, points out that Freeman was not only an excellent neurophysiologist, but also an applied mathematician. He relates Freeman’s work on attractor dynamics to his own theory of chaotic itinerancy, which could explain the phase transition in the olfactory system of an animal in an ‘I don’t know’ state, in the presence of an odorous input. Interestingly, Tsuda’s paper on chaotic itinerancy appeared about the same time (in 1987) as the seminal papers on chaotic neurodynamics by Skarda and Freeman, and that started a long and fruitful relationship between Freeman and Tsuda. Similarly fruitful relationships between Freeman and physicists are exemplified by Kozma and Vitiello, who worked with Freeman during his last couple of decades. Kozma and Davis describe in their paper Freeman’s cinematic theory of cognition, in terms of phase transitions in the cortical neuropil. With a starting point of Freeman’s K-sets and intentional neurodynamics, the authors expand the idea of an action–perception cycle into a ‘cycle of the creation of knowledge and meaning’ (CKM).
For a long time, Freeman was reluctant to consider any role of quantum mechanics for brain function, until he met with Giuseppe Vitiello, who was able to convince him about its usefulness. In the last decade, this interaction increased and the development of a quantum field theory of neurodynamics found its pinnacle in their co-authored paper, which was much discussed and hailed at the Tucson Conference on a Science of Consciousness in 2016, where Walter Freeman would have been active, had it not been for his death a few days before.
The fourth and final set of papers, gathered under the heading Perception, Intentionality, and Consciousness, are perhaps somewhat more philosophical than many of the other papers. The four contributions are authored by Christine Skarda, Paul Rapp and co-workers, Hans Liljenström, and Fanji Gu, respectively. Skarda and Freeman ‘co-inspired’ each other to the idea of chaos in brain dynamics, as well as to that of intentionality, which became so central to Freeman’s work in recent decades. In her paper here, Skarda develops Freeman’s enactive theory on perception, and calls for a re-evaluation of the theory with roots in Buddhist and ancient Greek philosophy. Both Rapp and Liljenström have also done work on chaotic neurodynamics, and, together with Gu, they have been involved in the series of meetings on cognitive neurodynamics which Freeman inspired his mainly Chinese and Japanese colleagues to develop in the early twenty-first century. This series of meetings was also accompanied by the establishment of a journal on the same topic, where the issue of relating neurodynamics to cognition and consciousness is central. In their paper, Rapp and colleagues point towards a clinical need to understand the physiological basis of consciousness, and present four philosophical models in response to the problem. Liljenström focuses his paper on intentionality, based on Freeman’s writings and dialogues on the topic, and shows how it can be seen as a driving force in individual life and evolution, also relating it to downward causation and free will. In the final paper of this set and of the entire special issue, Gu discusses several open questions regarding the problem of consciousness. In particular, he relates to Freeman neurodynamics, and hypothesizes that consciousness could best be understood in terms of a neurodynamic global workspace.
Some of the central problems of contemporary neuroscience are considered in the articles in this special issue, which will hopefully bring further insights and inspire new questions and ideas in the spirit of Walter Freeman, who was pioneering the field of neurodynamics and its relation to cognition and consciousness. The contributions in this issue address different aspects of Freeman’s research and philosophy, and also different perspectives on consciousness, which are often not so deeply rooted in experimental evidence and neuroscience theory as those linked to Freeman neurodynamics. This volume can thus be seen both as a legacy of Walter Freeman, as a neuroscientist, a mathematician, and a philosopher, but also pointing at profound problems related to brain and mind, which science just has begun to grapple with.
Stockholm, December 2017