Matteo Grasso

The problem of animal consciousness has profound implications on our concept of nature and of our place in the natural world. In philosophy of mind and cognitive neuroscience the problem of animal consciousness raises two main questions (Velmans, 2007): the distribution question (“are there conscious animals beside humans?”) and the phenomenological question (“what is it like to be a non-human animal?”). In order to answer these questions, many approaches take into account similarities and dissimilarities in animal and human behavior, e.g. the use of language or tools and mirror self-recognition (Allen and Bekoff, 2007), however behavioral arguments don’t seem to be conclusive (Baars, 2005). Cognitive neuroscience is providing comparative data on structural and functional similarities, respectively called “homologies” and “analogies”. Many experimental results suggest that the thalamocortical system is essential for consciousness (Edelman and Tononi, 2000; Tononi, 2008). The argument from homology states that the general structure of thalamocortical system remained the same in the last 100-200 million years, for it is neuroanatomically similar in all the present and past mammals and it didn’t change much during phylogeny (Allen and Bekoff, 2007). The argument from analogy states that the key functional processes correlated with consciousness in humans are still present in all other mammals and many other animals (Baars, 2005). These processes are information integration through effective cortical connectivity (Massimini et al., 2005; Rosanova et al., 2012) and elaboration of information at a global level (Dehaene and Changeux, 2011). On this basis, the Cambridge Declaration on Consciousness states that all mammals, birds, and many other animals (such as octopuses) possess the neurological substrates of consciousness (Low et al., 2012). Conscious experience is private (Chalmers, 1995; Nagel, 1974) therefore the answer to the phenomenological question may be impossible. Nevertheless, cognitive neuroscience may provide an answer to the distribution question, showing that conscious experience is not limited to humans since it is a major biological adaptation going back millions of years.

Sleep and dreaming are important daily phenomena that are receiving growing attention from both the scientific and the philosophical communities. The increasingly popular predictive brain framework within cognitive science aims to give a full account of all aspects of cognition. The aim of this paper is to critically assess the theoretical advantages of Predictive Processing (PP, as proposed by Clark 2013, Clark 2016; and Hohwy 2013) in defining sleep and dreaming. After a brief introduction, we overview the state of the art at the intersection between dream research and PP (with particular reference to Hobson and Friston 2012; Hobson et al. 2014). In the following sections we focus on two theoretically promising aspects of the research program. First, we consider the explanations of phenomenal consciousness during sleep (i.e. dreaming) and how it arises from the neural work of the brain. PP provides a good picture of the peculiarity of dreaming but it can’t fully address the problem of how consciousness comes to be in the first place. We propose that Integrated Information Theory (IIT) (Oizumi et al. 2014; Tononi et al. 2016) is a good candidate for this role and we will show its advantages and points of contact with PP. After introducing IIT, we deal with the evolutionary function of sleeping and dreaming. We illustrate that PP fits with contemporary researches on the important adaptive function of sleep and we discuss why IIT can account for sleep mentation (i.e. dreaming) in evolutionary terms (Albantakis et al. 2014). In the final section, we discuss two future avenues for dream research that can fruitfully adopt the perspective offered by PP: (a) the role of bodily predictions in the constitution of the sleeping brain activity and the dreaming experience, and (b) the precise role of the difference stages of sleep (REM (Rapid eye movement), NREM (Non-rapid eye movement) in the constitution and refinement of the predictive machinery.

Objective correlates—behavioral, functional, and neural—provide essential tools for the scientific study of consciousness. But reliance on these correlates should not lead to the ‘fallacy of misplaced objectivity’: the assumption that only objective properties should and can be accounted for objectively through science. Instead, what needs to be explained scientifically is what experience is intrinsically— its subjective properties—not just what we can do with it extrinsically. And it must be explained; otherwise the way experience feels would turn out to be magical rather than physical. We argue that it is possible to account for subjective properties objectively once we move beyond cognitive functions and realize what experience is and how it is structured. Drawing on integrated information theory, we show how an objective science of the subjective can account, in strictly physical terms, for both the essential properties of every experience and the specific properties that make particular experiences feel the way they do.

The problem of free will is deeply linked with the causal relevance of mental events. The causal exclusion argument claims that, in order to be causally relevant, mental events must be identical to physical events. However, Gibb has recently criticized it, suggesting that mental events are causally relevant as double preventers. For Gibb, mental events enable physical effects to take place by preventing other mental events from preventing a behaviour to take place. The role of mental double preventers is hence similar to what Libet names free won’t, namely the ability to veto an action initiated unconsciously by the brain. In this paper I will propose an argument against Gibb’s account, the causal irrelevance argument, showing that Gibb’s proposal does not overcome the objection of systematic overdetermination of causal relevance, because mental double preventers systematically overdetermine physical double preventers, and therefore mental events are causally irrelevant.

The metaphysics of powers (Shoemaker, 1980; Mumford, 2004; Marmodoro, 2009; Heil, 2012 among many others) is a promising conceptual framework that has been successfully put to use in many philosophical and scientific domains, but surprisingly its potential applications in the contemporary philosophy of mind are still under-investigated. This thematic issue aims to show that power ontology has implications concerning major questions in the contemporary philosophy of mind, such as: what is the metaphysical relationship between consciousness and the physical? Are phenomenal properties reducible to physical properties, fundamental, or emergent? How are we to explain notions such as belief, agency, and free will?

Integrated information theory attempts to account for both the quantitative and the phenomenal aspects of consciousness, and in taking consciousness as fundamental and widespread it bears similarities to panpsychist Russellian monism. In this paper I compare IIT's and RM's response to the conceivability argument, and their metaphysical account of conscious experience. I start by claiming that RM neutralizes the conceivability argument, but that by virtue of its commitment to categoricalism it doesn't exclude fickle qualia scenarios. I argue that IIT's core notion of intrinsic cause-effect power makes it incompatible with categoricalist versions of RM and, to the contrary, is best understood as entailing pandispositionalism, the view for which all properties are powers. I show that, thus construed, IIT can cope with both the conceivability and with the fickle qualia arguments, offers a promising way to account for the content of experience, and hence is preferable to categoricalist RM.

Causal reductionism is the widespread assumption that there is no room for additional causes once we have accounted for all elementary mechanisms within a system. Due to its intuitive appeal, causal reductionism is prevalent in neuroscience: once all neurons have been caused to fire or not to fire, it seems that causally there is nothing left to be accounted for. Here, we argue that these reductionist intuitions are based on an implicit, unexamined notion of causation that conflates causation with prediction. By means of a simple model organism, we demonstrate that causal reductionism cannot provide a complete and coherent account of ‘what caused what’. To that end, we outline an explicit, operational approach to analyzing causal structures.

The target article misrepresents the foundations of integrated information theory and ignores many essential publications. It, thus, falls to this lead commentary to outline the axioms and postulates of IIT and correct major misconceptions. The commentary also explains why IIT starts from phenomenology and why it predicts that only select physical substrates can support consciousness. Finally, it highlights that IIT's account of experience – a cause–effect structure quantified by integrated information – has nothing to do with “information transfer.”

Organoids and specifically human cerebral organoids (HCOs) are one of the most relevant novelties in the field of biomedical research. Grown either from embryonic or induced pluripotent stem cells, HCOs can be used as in vitro three-dimensional models, mimicking the developmental process and organization of the developing human brain. Based on that, and despite their current limitations, it cannot be assumed that they will never at any stage of development manifest some rudimentary form of consciousness. In the absence of behavioral indicators of consciousness, the theoretical neurobiology of consciousness being applied to unresponsive brain-injured patients can be considered with respect to HCOs. In clinical neurology, it is difficult to discern a capacity for consciousness in unresponsive brain-injured patients who provide no behavioral indicators of consciousness. In such scenarios, a validated neurobiological theory of consciousness, which tells us what the neural mechanisms of consciousness are, could be used to identify a capacity for consciousness. Like the unresponsive patients that provide a diagnostic difficulty for neurologists, HCOs provide no behavioral indicators of consciousness. Therefore, this article discusses how three prominent neurobiological theories of consciousness apply to human cerebral organoids. From the perspective of the Temporal Circuit Hypothesis, the Global Neuronal Workspace Theory, and the Integrated Information Theory, we discuss what neuronal structures and functions might indicate that cerebral organoids have a neurobiological capacity to be conscious.

The single day conference “Ontology, Mind and Free Will. A Workshop in Memory of E.J. Lowe (1950-2014)” took place at the Department of Humanities of the University of Macerata on March, 3 rd 2014. It included as speakers Sophie Gibb (Durham University), Mario De Caro (Roma Tre University) and Michele Paolini Paoletti (University of Macerata). This event was thought by the organizers in order to honor the British philosopher Ethan Jonathan Lowe, who suddenly passed away last January with infinite regret of the scientific community. The discussion of some of his major research topics, such as mental causation, free will and essence, was therefore meant as the right homage to one of the most influential philosophers who animated and deepened the debate of the last thirty years. Regarding the singular reviews of this report, Matteo Grasso took care of Sophie Gibb’s and Mario De Caro’s talks, while Mattia Sorgon reviewed Michele Paolini Paoletti’s.

Are colors features of objects “out there in the world” or are they features of our inner experience and only “in our head?” Color perception has been the focus of extensive philosophical and scientific debate. In this paper we discuss the limitations of the view that Chalmers’ (2006) has characterized as Primitivism, and we develop Marmodoro’s (2006) Constitutionalism further, to provide a metaphysical account of color perception in terms of causal powers. The result is Power-based Constitutionalism, the view that colors are (multi-track and multi-stage) powers of objects, whose (full) manifestations depend on the mutual manifestation of relevant powers of perceivers and the perceived objects being co-realized in mutual interaction. After a presentation of the tenets of Power-based Constitutionalism, we evaluate its strengths in contrast to two other recent power-based accounts: John Heil’s (2003, 2012) powerful qualities view and Max Kistler’s (2017) multi-track view.

This paper presents Integrated Information Theory (IIT) 4.0. IIT aims to account for the properties of experience in physical (operational) terms. It identifies the essential properties of experience (axioms), infers the necessary and sufficient properties that its substrate must satisfy (postulates), and expresses them in mathematical terms. In principle, the postulates can be applied to any system of units in a state to determine whether it is conscious, to what degree, and in what way. IIT offers a parsimonious explanation of empirical evidence, makes testable predictions, and permits inferences and extrapolations. IIT 4.0 incorporates several developments of the past ten years, including a more accurate translation of axioms into postulates and mathematical expressions, the introduction of a unique measure of intrinsic information that is consistent with the postulates, and an explicit assessment of causal relations. By fully unfolding a system's irreducible cause-effect power, the distinctions and relations specified by a substrate can account for the quality of experience.