How consciousness appeared much earlier in evolutionary history than is commonly assumed, and why all vertebrates and perhaps even some invertebrates are conscious. How is consciousness created? When did it first appear on Earth, and how did it evolve? What constitutes consciousness, and which animals can be said to be sentient? In this book, Todd Feinberg and Jon Mallatt draw on recent scientific findings to answer these questions—and to tackle the most fundamental question about the nature of consciousness: how does (...) the material brain create subjective experience? After assembling a list of the biological and neurobiological features that seem responsible for consciousness, and considering the fossil record of evolution, Feinberg and Mallatt argue that consciousness appeared much earlier in evolutionary history than is commonly assumed. About 520 to 560 million years ago, they explain, the great “Cambrian explosion” of animal diversity produced the first complex brains, which were accompanied by the first appearance of consciousness; simple reflexive behaviors evolved into a unified inner world of subjective experiences. From this they deduce that all vertebrates are and have always been conscious—not just humans and other mammals, but also every fish, reptile, amphibian, and bird. Considering invertebrates, they find that arthropods (including insects and probably crustaceans) and cephalopods (including the octopus) meet many of the criteria for consciousness. The obvious and conventional wisdom–shattering implication is that consciousness evolved simultaneously but independently in the first vertebrates and possibly arthropods more than half a billion years ago. Combining evolutionary, neurobiological, and philosophical approaches allows Feinberg and Mallatt to offer an original solution to the “hard problem” of consciousness. (shrink)

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.”. (shrink)

Current knowledge of the genetic, epigenetic, behavioural and symbolic systems of inheritance requires a revision and extension of the mid-twentieth-century, gene-based, 'Modern Synthesis' version of Darwinian evolutionary theory. We present the case for this by first outlining the history that led to the neo-Darwinian view of evolution. In the second section we describe and compare different types of inheritance, and in the third discuss the implications of a broad view of heredity for various aspects of evolutionary theory. We end with (...) an examination of the philosophical and conceptual ramifications of evolutionary thinking that incorporates multiple inheritance systems. (shrink)

Claims about consciousness in animals are often made in support of their moral standing. Peter Carruthers argues that there is no fact of the matter about animal consciousness and it is of no scientific or ethical significance. Sympathy for an animal can be grounded in its mental states, but should not rely on assumptions about its consciousness.

Aphantasia is a recently discovered disorder characterised by the total incapacity to generate visual forms of mental imagery. This paper proposes that aphantasia raises important theoretical concerns for the ongoing debate in the philosophy and science of consciousness over the nature of dreams. Recent studies of aphantasia and its neurobehavioral correlates reveal that the majority of aphantasics, whilst unable to produce visual imagery while awake, nevertheless retain the capacity to experience rich visual dreams. This finding constitutes a novel explanandum for (...) theories of dreaming. Specifically, I argue that the recent dream reports of aphantasics constitute an empirical challenge to the emerging family of views which claim that dreams are essentially imaginative experiences, constitutively involving the kinds of mental imagery which aphantasics, ex-hypothesi, lack. After presenting this challenge in the context of Jonathan Ichikawa’s recent arguments for this view, I argue that this empirical challenge may be overcome if the imagination theorist abandons Ichikawa’s account of dreaming in favour of a modified version. This involves the claim that dreams are essentially inactive and constitutively involve non voluntary forms of imagination. I conclude with a suggestion for further research which can test the viability of this alternative hypothesis, and move the debate forward. (shrink)

This commentary focuses on the importance of attention skills in the development of universal associative learning, and it explains why the centrality of attention in UAL presents a considerable difficulty for the UAL approach. Attentional abilities are not just developmentally related to UAL but are in fact explanatory of UAL. The main problem is that all the types of attention involved in UAL can be dissociated from consciousness. This means that while attention skills for UAL might be necessary for consciousness, (...) they are not sufficient because they can all occur unconsciously. Thus, the possibility that UAL capacities might not be sufficient for consciousness cannot be eliminated, thereby challenging the key claim of the UAL approach. (shrink)

The issue of the biological origin of consciousness is linked to that of its function. One source of evidence in this regard is the contrast between the types of information that are and are not included within its compass. Consciousness presents us with a stable arena for our actions—the world—but excludes awareness of the multiple sensory and sensorimotor transformations through which the image of that world is extracted from the confounding influence of self-produced motion of multiple receptor arrays mounted on (...) multijointed and swivelling body parts. Likewise excluded are the complex orchestrations of thousands of muscle movements routinely involved in the pursuit of our goals. This suggests that consciousness arose as a solution to problems in the logistics of decision making in mobile animals with centralized brains, and has correspondingly ancient roots. (shrink)

A broad range of evidence regarding the functional organization of the vertebrate brain – spanning from comparative neurology to experimental psychology and neurophysiology to clinical data – is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to form (...) a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain – culminating in the cerebral cortex of mammals – came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone. (Published Online May 1 2007) Key Words: action selection; anencephaly; central decision making; consciousness; control architectures; hydranencephaly; macrosystems; motivation; target selection; zona incerta. (shrink)

Birch, Ginsburg, and Jablonka, in an article in this issue of Biology and Philosophy, provided a much-needed condensation of their well-reasoned theory of Unlimited Associative Learning. This theory compellingly identifies the conscious animals and the time when the evolutionary transition to consciousness was completed. The authors convincingly explained their use of UAL as a “transition marker,” identified two more features by which UAL can be recognized, showed how UAL’s learning features relate to consciousness, and how investigating consciousness is analogous to (...) investigating life. My constructive criticisms are that I wish they had taken a stand on which organisms and entities are not conscious, and I feel they made too many predictions by which to test the UAL theory. That is, some of the proposed tests are unnecessary because parts of UAL are already supported by enough evidence, and other proposed tests are so ambitious as to be nearly impossible to complete. Finally, UAL has a major, detailed, sub-hypothesis that says such learning led to stress and to the evolution of mechanisms to cope with this stress; but this idea is speculative and requires the most basic testing to judge whether it could be valid. (shrink)

Birch, Ginsburg, and Jablonka lay out a very convincing case for an important transition marker: unlimited associative learning. Especially welcome are the empirical predictions. I focus here not on the question of how to infer phenomenal consciousness from this behavioral metric, but on possible novel applications of this useful and fundamental framework. Specifically, I highlight two aspects of biology that are often not considered in philosophy of mind approaches that focus on natural species and evolutionary time scales. These are the (...) ability of minds and bodies to change drastically on the time scale of an individual experiencing subject, and bioengineering of novel living forms with no evolutionary history at the organism level. Both of these aspects provide interesting new contexts within which to explore UAL and its implications. (shrink)

In this commentary I expand on the first of Noble’s illusions, the selection metaphor. Building on my work with Simona Ginsburg on the evolution of minimal consciousness, I argue that the existence of some complex sensory and motor patterns in the living world can be accounted for only through the evolution of conscious choice.

The target paper (building on Ginsburg and Jablonka in JTB 381:55–60, 2015, The evolution of the sensitive soul: Learning and the origins of consciousness, MIT Press, USA, 2019) makes a significant and novel claim: that positive cases of non-human consciousness can be identified via the capacity of unlimited associative learning (UAL). In turn, this claim is generated by a novel methodology, which is that of identifying an evolutionary ‘transition marker’, which is claimed to have theoretical and empirical advantages over other (...) approaches. In this commentary I argue that UAL does not function as a successful transition marker (as defined by the authors), and has internal problems of its own. However, I conclude that it is still a very productive anchor for new research on the evolution of consciousness. (shrink)

Birch, Ginsburg, and Jablonka suggest that Unlimited Associative Learning is a “transition marker” in the evolutionary process that produced consciousness, and organizes research by tying together a range of “hallmarks” of consciousness. I argue that the features they recognize as “hallmarks” are indeed important in the evolution of consciousness, but UAL may have a more limited role.

We present Birch and colleagues with a dilemma. On one interpretation, they aim to chart the distribution of a sort of minimal perceptual awareness across the animal kingdom, where that awareness can be fully characterized in third-person psychological terms. On this interpretation, the project is worthy but dull, since it doesn’t touch the question that has excited most people: whether other animals are phenomenally conscious. On an alternative interpretation, in contrast, they hope to resolve this latter question, arguing that phenomenal (...) consciousness is extremely widespread. But if this is their intention, then their argument begs the question. (shrink)

Birch et. al. see their model as incompatible with higher-order-thought (HOT) theories of consciousness, on which a state is conscious if one is in some suitable way aware of that state. They see higher-order (HO) awareness as an “extra ingredient”. But since Birch et al go on to say that “[t]his is not the place for a detailed discussion of HOT theories,” they don’t address why they take HO awareness to be an extra ingredient or why HOT theorists are convinced (...) that it’s needed. In this commentary we argue that higher-order theories are a crucial for understanding consciousness. (shrink)

The higher order approach to consciousness attempts to build a theory of consciousness from the insight that a conscious state is one that the subject is conscious of. There is a well-known objection1 to the higher order approach, a version of which is fatal. Proponents of the higher order approach have realized that the objection is significant. They have dealt with it via what David Rosenthal calls a “retreat” (2005b, p. 179) but that retreat fails to solve the problem.

There is no agreement on whether any invertebrates are conscious and no agreement on a methodology that could settle the issue. How can the debate move forward? I distinguish three broad types of approach: theory-heavy, theory-neutral and theory-light. Theory-heavy and theory-neutral approaches face serious problems, motivating a middle path: the theory-light approach. At the core of the theory-light approach is a minimal commitment about the relation between phenomenal consciousness and cognition that is compatible with many specific theories of consciousness: the (...) hypothesis that phenomenally conscious perception of a stimulus facilitates, relative to unconscious perception, a cluster of cognitive abilities in relation to that stimulus. This “facilitation hypothesis” can productively guide inquiry into invertebrate consciousness. What is needed? At this stage, not more theory, and not more undirected data gathering. What is needed is a systematic search for consciousness-linked cognitive abilities, their relationships to each other, and their sensitivity to masking. (shrink)

The Evolution of the Sensitive Soul is a landmark attempt to make progress on the problem of animal consciousness. Ginsburg and Jablonka propose a general cognitive marker of the presence of consciousness: Unlimited Associative Learning. They use this marker to defend a generous view about the distribution of consciousness in the natural world, on which a capacity for conscious experience is common to all vertebrates, many arthropods and some cephalopod molluscs. They use this inferred distribution to defend a view about (...) the evolution of consciousness, on which it has evolved at least three times, first evolved at around the time of the Cambrian explosion, and was in fact the driving force behind that explosion. In this essay review, I reflect critically on the book’s central idea: the proposal that Unlimited Associative Learning provides a general marker of consciousness. (shrink)

How is it that thoroughly physical material beings such as ourselves can think, dream, feel, create and understand ideas, theories and concepts? How does mere matter give rise to all these non-material mental states, including consciousness itself? An answer to this central question of our existence is emerging at the busy intersection of neuroscience, psychology, artificial intelligence, and robotics.In this groundbreaking work, philosopher and cognitive scientist Andy Clark explores exciting new theories from these fields that reveal minds like ours to (...) be prediction machines - devices that have evolved to anticipate the incoming streams of sensory stimulation before they arrive. These predictions then initiate actions that structure our worlds and alter the very things we need to engage and predict. Clark takes us on a journey in discovering the circular causal flows and the self-structuring of the environment that define "the predictive brain." What emerges is a bold, new, cutting-edge vision that reveals the brain as our driving force in the daily surf through the waves of sensory stimulation. (shrink)

How can phenomenal consciousness exist as an integral part of a physical universe? How can the technicolour phenomenology of our inner lives be created out of the complex neural activities of our brains? Many have despaired of finding answers to these questions; and many have claimed that human consciousness is inherently mysterious. Peter Carruthers argues, on the contrary, that the subjective feel of our experience is fully explicable in naturalistic terms. Drawing on a variety of interdisciplinary resources, he develops and (...) defends a novel account in terms of higher-order thought. He shows that this can explain away some of the more extravagant claims made about phenomenal consciousness, while substantively explaining the key subjectivity of our experience. Written with characteristic clarity and directness, and surveying a wide range of extant theories, this book is essential reading for all those within philosophy and psychology interested in the problem of consciousness. (shrink)

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. (shrink)

Humans have been shown capable of performing many cognitive tasks using information of which they are not consciously aware. This raises questions about what role consciousness actually plays in cognition. Here, we explored whether participants can learn cue-target contingencies in an attentional learning task when the cues were presented below the level of conscious awareness, and how this differs from learning about conscious cues. Participants’ manual (Experiment 1) and saccadic (Experiment 2) response speeds were influenced by both conscious and unconscious (...) cues. However, participants were only able to adapt to reversals of the cue-target contingencies (Experiment 1) or changes in the reliability of the cues (Experiment 2) when consciously aware of the cues. Therefore, although visual cues can be processed unconsciously, learning about cues over a few trials requires conscious awareness of them. Finally, we discuss implications for cognitive theories of consciousness. (shrink)

Carruthers (2000; 2005) provides a general defence of reductive representationalism about phenomenal consciousness while critiquing first-order theories of the sort proposed by Baars (1988), Tye (1995), Dennett (2001), and others (thereby motivating a form of higher-order account). The present paper defends first-order theories against that attack.