Simona Ginsburg

In our target article, “Learning and the evolution of conscious agents” we outlined an evolutionary approach to consciousness, arguing that the evolution of a form of open-ended, representational, and generative learning (unlimited associative learning, UAL) drove the evolution of consciousness. Our view highlights the dynamics and functions of consciousness, delineates its taxonomic distribution and suggests a framework for exploring its developmental and evolutionary modifications. The approach we offer resonates with biosemioticians’ views, but as the responses to our target article show, our proposal also faces challenges and has led to suggestions that extend, develop and qualify it. Our response to the 14 varied and rich commentaries starts with the recurring and deep question raised by many of them – the relation between life and sentience. We explore this question by introducing and expanding on “vivaciousness”, a term we coined to describe the turbulent, flexible exploration-stabilization processes inherent in the living condition, as well as addressing the related concepts of Umwelt and selfhood. We then consider the question of the adequacy of unlimited associative learning (UAL) as an evolutionary transition marker (ETM) of minimal consciousness (rather than as a marker of a complex form of sentience), and the possible precursors of sentience. The engagement with these broad themes is entangled with a discussion of evolutionary transitions, constitutive emergence and the function/s of consciousness. The suggestions of our commentators, urging us to explore new concepts and new avenues of research within the framework of a richer view of evolution are then discussed. We end by briefly considering what we regard as a conceptual lacuna, which is leading to the indiscriminate use of the term “sentience” and which awaits further investigation.

A new theory about the origins of consciousness that finds learning to be the driving force in the evolutionary transition to basic consciousness. What marked the evolutionary transition from organisms that lacked consciousness to those with consciousness—to minimal subjective experiencing, or, as Aristotle described it, “the sensitive soul”? In this book, Simona Ginsburg and Eva Jablonka propose a new theory about the origin of consciousness that finds learning to be the driving force in the transition to basic consciousness. Using a methodology similar to that used by scientists when they identified the transition from non-life to life, Ginsburg and Jablonka suggest a set of criteria, identify a marker for the transition to minimal consciousness, and explore the far-reaching biological, psychological, and philosophical implications. After presenting the historical, neurobiological, and philosophical foundations of their analysis, Ginsburg and Jablonka propose that the evolutionary marker of basic or minimal consciousness is a complex form of associative learning, which they term unlimited associative learning (UAL). UAL enables an organism to ascribe motivational value to a novel, compound, non-reflex-inducing stimulus or action, and use it as the basis for future learning. Associative learning, Ginsburg and Jablonka argue, drove the Cambrian explosion and its massive diversification of organisms. Finally, Ginsburg and Jablonka propose symbolic language as a similar type of marker for the evolutionary transition to human rationality—to Aristotle's “rational soul.”

Veit suggests that the challenge of coordinating movement in multicellular organisms led to the evolution of a prioritizing value system, which rendered organisms complex enough to be sentient and drove the Cambrian explosion, while the absence of this evaluation system led to the demise of Ediacaran animals. In this commentary we criticize Veit’s terminology and evolutionary proposals, arguing that his terminology and evolutionary scenarios are problematic, and put forward alternative proposals. We suggest that sentience is a system property, and that the evolution of sentience was the outcome of the evolution of open-ended associative learning, which included the coevolution of sensory, motor, memory, and value subsystems. We suggest that these coevolutionary system dynamics were a factor in the Cambrian explosion and contributed to the extinction of the Ediacaran biota.

The scientific study of consciousness or subjective experiencing is a rapidly expanding research program engaging philosophers of mind, psychologists, cognitive scientists, neurobiologists, evolutionary biologists and biosemioticians. Here we outline an evolutionary approach that we have developed over the last two decades, focusing on the evolutionary transition from non-conscious to minimally conscious, subjectively experiencing organisms. We propose that the evolution of subjective experiencing was driven by the evolution of learning and we identify an open-ended, representational, generative and recursive form of associative learning, which we call Unlimited Associative Learning (UAL), as an evolutionary transition marker of minimal consciousness. This evolutionary marker provides evidence that the evolutionary transition to consciousness has gone to completion and allows reverse-engineering from this learning capacity to the system that enables it – making possible the construction of a toy model of UAL. The model allows us to identify some of the key processes and structures that constitute minimal consciousness, points its taxonomic distribution and the ecological context in which it first emerged, highlights its function and suggests a framework for exploring developmental and evolutionary modifications of consciousness. We point to ways of experimentally testing the relationship between UAL and consciousness in human and in non-human animals and discuss the theoretical and ethical implications of our approach. The framework we offer allows the exploration of the evolutionary changes in agency, value systems, selective processes and goals that were involved in the transition to subjective experiencing from a perspective that resonates with the approaches of bio-semioticians.

This is a response to the nine commentaries on our target article “Unlimited Associative Learning: A primer and some predictions”. Our responses are organized by theme rather than by author. We present a minimal functional architecture for Unlimited Associative Learning that aims to tie to together the list of capacities presented in the target article. We explain why we discount higher-order thought theories of consciousness. We respond to the criticism that we have overplayed the importance of learning and underplayed the importance of spatial modelling. We decline the invitation to add a negative marker to our proposed positive marker so as to rule out consciousness in plants, but we nonetheless maintain that there is no positive evidence of consciousness in plants. We close by discussing how UAL relates to development and to its material substrate.

The attribution of sentience or consciousness to plants is currently a topic of debate among biologists and philosophers. The claim that plants are conscious is based on three arguments: (i) plants, like all living organisms, are sentient (biopsychism); (ii) there is a strong analogy between the phloem transport system of plants and the nervous system of animals; and (iii) plants are the cognitive equals of sentient animals. On the basis of a model of consciousness that spells out criteria for assigning sentience to a living organism and presents a diagnostic evolutionary marker of consciousness, we argue that these arguments are flawed and discuss some of the ethical issues they raise.

Over the past two decades, Ginsburg and Jablonka have developed a novel approach to studying the evolutionary origins of consciousness: the Unlimited Associative Learning framework. The central idea is that there is a distinctive type of learning that can serve as a transition marker for the evolutionary transition from non-conscious to conscious life. The goal of this paper is to stimulate discussion of the framework by providing a primer on its key claims and a clear statement of its main empirical predictions.

We suggest a teleological approach to subjective experiencing or phenomenal consciousness. Like living, subjective experiencing is a teleology-constituting mode of being, which is made up of coupled, functional processes. We explicate our notion of a 'teleological mode of being' and distinguish between three different modes: a living (non-sentient) mode of being, a sentient mode of being, and a rational-symbolic (human) mode of being, which correspond to the three levels of soul suggested by Aristotle. These evolved teleological modes of being are characterized by the possession of distinct, hierarchically nested goals and value systems. We argue that the functions of parts and processes within living systems have to be situated within the appropriate teleological frame of reference. Our evolutionary and comparative approach to the mode of being of subjectively experiencing animals clarifies why functions are best attributed to the parts that constitute sentience. Our proposal resolves the problem of attributing functions to phenomenal consciousness, resonates with basic teleological intuitions and distinctions, and corresponds to the modern broad understanding of selection and evolution.

Heyes argues that human metacognitive strategies (“cognitive gadgets” or “mills”) are the products of cultural evolution based on domain‐general cognition with few simple biases. Although like Heyes, we believe that the evolution of domain‐general cognitive processes played a crucial role in the evolution of human cognition, we argue that Heyes' distinction between mills and grist is too sharp, that associative learning evolved gradually to become more complex and hierarchical, something that is not captured by the system 1/system 2 distinction, and that human cognitive plasticity required the genetic accommodation of gadget‐specific processes that led to more plasticity‐enhancing human‐specific biases.

We suggest an approach to studying consciousness that focuses on its evolutionary origins. The proposed framework is inspired by the study of the transition from inanimate matter to life, which proved extremely useful for understanding what 'life' entails. We follow the theoretical and methodological scheme put forward by Tibor Ganti, who suggested a marker for the transition to life -- an evolved feature that is sufficient for ascribing dynamic persistence to a minimal living system and that can serve as a point of departure for reconstructing it. We apply this approach to consciousness and suggest an overt behavioural trait -- unlimited associative learning -- as a candidate transition marker. We show that the enabling system of UAL instantiates the set of properties that are considered jointly sufficient for minimal consciousness, and discuss the experimental predictions and the implications of our approach for the taxonomic distribution of consciousness in the animal world.

There are many different notions of information in logic, epistemology, psychology, biology and cognitive science, which are employed differently in each discipline, often with little overlap. Since our interest here is in biological processes and organisms, we develop a taxonomy of functional information that extends the standard cue/signal distinction. Three general, main claims are advanced here. This new taxonomy can be useful in describing learning and communication. It avoids some problems that the natural/non-natural information distinction faces. Functional information is​ ​produced through exploration and stabilisation processes.

This is the first of two papers in which we propose an evolutionary route for the transition from sensory processing to unlimited experiencing, or basic consciousness. We argue that although an evolutionary analysis does not provide a formal definition and set of sufficient conditions for consciousness, it can identify crucial factors and suggest what evolutionary changes enabled the transition. We believe that the raw material from which feelings were molded by natural selection was a global sensory state that we call overall sensation, which is a by-product of the incessant activity of the highly interconnected nervous systems that characterize all neural animals. We argue that global sensory states generated limited experiencing once they became coupled to the simplest kinds of nervous-system-mediated learning, a coupling that occurred in the most ancient taxa of neural animals, which were similar to present-day cnidarians and ctenophores. In such animals, limited experiencing involves a small number of persistent global sensory states. These sensory states, however, do not have a function and do not act as motivational states. As we argue in the next paper, with the evolution of associative learning they evolved into systems that gave animals basic consciousness

We discuss the evolutionary transition from animals with limited experiencing to animals with unlimited experiencing and basic consciousness. This transition was, we suggest, intimately linked with the evolution of associative learning and with flexible reward systems based on, and modifiable by, learning. During associative learning, new pathways relating stimuli and effects are formed within a highly integrated and continuously active nervous system. We argue that the memory traces left by such new stimulus-effect relations form dynamic, flexible, and varied global sensory states, which we call categorizing sensory states . These CSSs acquired a function: they came to act as internal “evaluators” and led to positive and negative reinforcement of new behavior. They are therefore the simplest, distinct, first-person motivational states that an animal can have. They constitute what we call basic consciousness, and are the hallmark of animals that can experience. Since associative learning has been found in many invertebrate taxa that first appeared during the Cambrian era, we propose that the processes underlying basic consciousness are phylogenetically ancient, and that their emergence may have fueled the Cambrian explosion