# Epilogue: Intermittent Synchronization in Context Throughout this book, we have emphasized a universal principle concerning the creation of function in human systems at all levels of analysis, from brains to societies. To perform a function, a subset of elements in a system become progressively synchronized to form a functional unit that becomes disassembled upon completion of the function or in response to unsuccessful performance of the function. In this sense, the larger system is not a dynamical system that performs a task, but rather represents an ensemble of elements from which a subset is integrated by synchronization to form a functional unit. On each occasion, a somewhat different configuration of elements is likely to be engaged in an ad ho manner to create the working dynamical system to perform a function. The particular configuration of elements is dependent to some degree on the momentary context in which the system is being created. It is also the case that each assembly of elements is affected by previous assemblies. Because the architecture of the working system is not stable, the dynamical properties of the system vary across functions. Human and social systems thus cannot be described as having an invariant stable structure with well-defined deterministic properties. Synchronization, then, is not an end-state but rather a part of a larger process involving the progressive assembly, disassembly, and reassembly of elements. If synchronization was complete and constant, as if it were the goal of human experience, the system in question would fail to function in a dynamic environment defined in terms of ever-changing task demands, challenges, and affordances. ## Human Complexity Revisited The intermittent synchronization perspective has important consequences for the nature of complexity in human experience. This is perhaps easiest to appreciate with respect to the functioning of the mind. The human brain and its manifestation as mind are arguably the most complex structures in the universe. One manifestation of this complexity is the ever-changing nature of the stream of consciousness, as described by James, Burkhardt, Bowers, and Skrupskelis (1890). He noted that although mental process has an underlying structure, the flow of thought never repeats itself in exactly the same fashion from one occasion to the next. In the intermittent synchronization scenario, the stream of thought on any occasion represents a unique configuration of a subset of elements from the larger cognitive structure. And since mind is an open system, the configuration of mental elements depends not only the previous state of the mind, but also is influenced by momentary and often subtle factors. Even the most repeated experiences are never truly identical. A person may awaken at the same time and in the same bed on consecutive days and observe a tree outside the bedroom window. Although all the elements may be identical from Day 1 to Day 2, the experience of looking at the tree may be different on Day 2 because of the other experiences the person has had since Day 1. So although the flow of thought is bounded, the exact pattern may never repeat itself, changing instead in a manner that defies precise prediction. In a similar vein, when two individuals discuss a problem while taking a walk, accidental elements in the environment (e.g., perception of a cloud) may become integrated in the stream of thought, slightly altering the specific assembly of thoughts relevant to the problem. This may have the effect of inducing novelty and facilitating a potential creative solution. From the perspective of the human mind as an open system, the effect of random incoming information goes beyond serving as a source of unpredictable and potentially disruptive noise to influence the architecture of the working system. Even in the absence of external influences, the flow of thought may be unpredictable, yet functional, because of the accidental nature of internal influ-ences, from momentary sensations to the activation of long-term memories. Hence, randomness, whether due to stochastic processes, internal dynamics, or unpredictable effects of context, may influence the process of assembling the functional units rather than simply adding noise to the working of an already assembled system. In this perspective the dynamics of mind is deeply unpredictable. The unpredictability is more basic than unpredictability of chaotic systems caused by sensitivity to initial conditions (Lorenz, 1963). In chaotic dynamical systems any imprecision of the measurement of the initial conditions, or infinitesimally small influence (so called butterfly effect) results in large differences after some time, leading to the inability to predict the state of the system. Although in chaotic systems the state of the system in a specific time moment is unpredictable, the temporal evolution of the system follows established trajectories. Because functional units may be assembled in different configurations each time they are created they dynamical properties .i.e their temporal trajectories may be potentially quite different. Now knowing in advance in what configuration the functional unit will be assembled, it may be impossible to predict the trajectory of the system. In this sense, the rules describing the functioning of the human mind are not stable. Rather, such rules evolve and change following the ever-changing nature of the mind's working architecture. The mind thus is not a stable entity, but rather is constantly being re-created to produce functions in response to external challenges, goals and plans, or simply mind-wandering (e.g., Baird et al., 2012). The simultaneous expression of uniqueness and an underlying structure exists as well at other levels of human experience. In a close relationship, the partners have a well-defined set of roles, daily routines, and rituals. Despite the structure provided by these roles, routines, and rituals, the precise features of the partners' interaction are never exactly the same from one occasion to the next. Even when enacting the same script (e.g., preparing a dinner and doing so with the same level of affect and motivation, the partners' verbal and nonverbal communication will be unique on each occasion. Different words will be used and assembled into different sentences, for example. So although a close relationship can become highly routine, there is flexibility and variety in the specific manner in which the partners interact. The implications of the intermittent synchronisation perspective for the ever-evolving nature of functional units is apparent as well at the level of human groups. As discussed in the chapter on group-level synchronisation, different subsets of individuals synchronise to perform different group functions. Even in a group that has a stable and formal structure, different subsets of individuals are likely to be called upon to perform a group task. And even if the same subset of individuals is formed to complete a task, the relations among them may well vary in accordance with task demands. ## Human Flexibility Versus Rigidity The ever-changing nature of mental and social systems does not imply that people always function in a flexible manner. This is readily apparent at the level of the mind. Research has shown that at both the level of the brain and the mind, routine actions that are repeated have the potential to become automatic. Indeed, a very common distinction in both mind and action is that between controlled and automatic processes. Controlled processes involve conscious attention, are flexible, relatively slow, and serial in nature. Brain imaging techniques have shown that the neural circuits underlying controlled processes involve selective activation of multiple brain regions resulting in the formation of complex functional units with a strong potential for uniqueness. This provides for high flexibility and uniqueness of the process, which is experienced as consciousness (Tononi & Edelman, 1998). In contrast, automatic processes do not require conscious attention, cannot be controlled at will, and are inflexible and rigid (e.g., Bargh & Chartrand, 1999; Shiffrin & Schneider, 1977). As the task becomes increasingly automatic, synchronisation becomes limited to the neural circuits responsible for performing the required function (i.e., task). The rigid nature of the functional units underlying automatic processes is responsible for routine and thus predictable dynamics. Social relationships can also lose their flexibility and become rigid. In a close relationship, this is tantamount to highly scripted interactions that play out without conscious reflection, even to the point of repeating the same word choices and syntax. The repetitive nature of such relationships is not necessarily devoid of affect and intensity, but nonetheless rarely promotes to the richness of partner's interaction or the resolution of issues in the relationship. In groups, meanwhile, the roles defining interaction and function may become highly inflexible, preventing the generation of novel activities or the embracing on new possibilities. Groups that effectively perform their functions are characterised by richer and changing patterns of connections among group members, and more complex and non-repetitive dynamics. In support of this reasoning, Losada (1999) has demonstrated that low-performing groups are characterised by a small number of connections among group members and simple dynamics. High-performing groups, in contrast, are characterised by a high number of connections and rich, complex patterns of dynamics. In highly effective corporations, for example, the managing team constantly reconfigures itself to meet the demands of tasks and challenges. ## Summing Up and Looking Ahead Our aim in this book was to present how structure, dynamics, and function are related across otherwise distinct domains of psychological and social reality. In this endeavour, we have reached into very different lines of research in neuroscience, cognitive psychology, social psychology, and other social sciences. Although distinct in very important ways, these domains of inquiry share a basic principle responsible for the emergence of function. Thus, intermittent synchronisation of elements in the performance of functions can be demonstrated in the workings of the brain, the mind, personal action, social relationships, and groups. This general perspective has previously found expression in different ways in specific areas of theory and research. Indeed, the notion of functional units can be traced to the early 20th century, as expressed in Gestalt psychology. The strictest empirical verification of intermittent synchronisation in the formation of functional units has been achieved in recent years in the study of neuroscience. However, it took the development of advanced tools and methods (e.g., network science, coupled dynamical systems, and advances in computer simulation, visualisation, and data analytic methods) to go from metaphor to the possibility of empirical confirmation of this perspective with respect to interpersonal and group dynamics. This development, however, should be looked upon a work in progress. At present, the precision of the intermittent synchronisation varies considerably across disciplines. Observations that are taken for granted and almost trivial in one area (e.g., brain function) may be radically novel in the context of other areas (e.g., societal processes). Accordingly, the precision manifest in different chapters of this book varies, reflecting the current state of science in the respective areas discussed in these chapters. With the growing appreciation of the role of synchronisation in brains, minds, groups, organisations, and societies, separate discoveries are likely to be integrated into a more unified understanding of human and social functioning. We hope that this book has provided a step toward this goal.