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. (shrink)

In this chapter, it is argued that the Mind-Body Powers model of neural correlates of consciousness provides a metaphysical framework that yields the theoretical possibility of empirically detecting consciousness. Since the model is informed by an Aristotelian-Thomistic hylomorphic ontology rather than a physicalist ontology, it provides a philosophical foundation for the science of consciousness that is an alternative to physicalism. Our claim is not that the Mind-Body Powers model provides the only alternative, but rather that it provides a sufficient framework (...) for empirically detecting and scientifically studying consciousness. Elsewhere, the integrated information theory’s prediction about the neural correlate of being conscious has been used to illustrate how the Mind-Body Powers model grounds the possibility of empirically detecting consciousness (see M. Owen, 2021, ch. 8). The theory’s prediction was used as one plausible example of a hypothesis about the nature and location of the neural correlate that can be combined with the model. However, there is no settled conclusion about which neurobiological theory of consciousness accurately identifies the neural mechanisms corresponding to being conscious (NAS, 2021, p. 39; Sattin et al., 2021; Seth, 2017; Seth & Bayne, 2022). Therefore, this work will employ another plausible neurobiological prediction provided by the Temporal Circuit Hypothesis. The hypothesis is combined with the Mind-Body Powers model to demonstrate that empirically detecting consciousness is metaphysically plausible wholly apart from a physicalist framework. (shrink)

Studies have shown that some covertly conscious brain-injured patients, who are behaviorally unresponsive, can reply to simple questions via neuronal responses. Given the possibility of such neuronal responses, Andrew Peterson et al. have argued that there is warrant for some covertly conscious patients being included in low-stakes medical decisions using neuronal responses, which could protect and enhance their autonomy. The justification for giving credence to alleged neuronal responses must be analyzed from various perspectives, including neurology, bioethics, law, and as we (...) suggest, philosophy of mind. In this article, we analyze the warrant for giving credence to neuronal responses from two different views in philosophy of mind. We consider how nonreductive physicalism’s causal exclusion problem elicits doubt about interpreting neural activity as indicating a conscious response. By contrast, such an interpretation is supported by the mind-body powers model of neural correlates of consciousness inspired by hylomorphism. (shrink)

Sietske A.L. van Till and Eline M. Bunnik (2024) have recently expressed a concern about science miscommunication regarding human brain organoids. They worry that the mereological fallacy is often being committed when the possibility of brain organoid psychological capacities such as consciousness and intelligence are considered, especially by bioethicists discussing the moral status of human brain organoids. Focusing specifically on one psychological capacity, namely consciousness, this article begins with a brief introduction to van Till and Bunnik’s concern about the mereological (...) fallacy as it relates to brain organoids. It is then shown that whether the mereological fallacy is being committed depends on commitments in philosophy of mind about how consciousness relates to the brain and its neural mechanisms. This is demonstrated by appealing to two different example views about the ontology of consciousness embraced by J.J.C. Smart’s type identity theory and a version of hylomorphism. The article ends with a discussion of how neurobiological theories of consciousness can be intertwined with ontological commitments about consciousness that have significant implications for HBOs. An awareness of this can yield a philosophically informed application of neurobiological theories to the topic of whether HBOs could be conscious. (shrink)

Information processing that subserves conscious cognitive functions is thought to involve recurrent signaling through feedforward and feedback loops among hierarchically arranged functional regions of the cerebral cortex. In the current issue of Consciousness and Cognition, Lee et al. report that loss of consciousness, as produced by a bolus injection of the general anesthetic propofol to human volunteers, was accompanied by a decrease in wide-band EEG feedback connectivity from frontal cortex to parietal cortex, confirming a prediction from previous experimental studies. Interestingly, (...) frontoparietal feedback connectivity did not fully recover after the anesthetic effect wore off and the subjects first opened their eyes in response to a verbal command. Possible interpretations of the results and their implications with respect to the neural correlates of consciousness and unconsciousness are discussed. (shrink)

Whether consciousness is unidimensional with states defined along a single scale or it consists of multiple fundamental dimensions has been debated. Clinical assessment of consciousness distinguishes the content of consciousness (awareness) and the level of consciousness (wakefulness or arousal), which conflates firstperson phenomenal properties with third-person observable properties. The state of consciousness is more appropriately defined in terms of subjective level and content which are interdependent. On this account, the state of consciousness is exclusively defined by the experienced mental content, (...) i.e.awareness, whereas behaviour and cognition are overt expressions of the state. Wakefulness and arousal are predisposing factors for specific forms of conscious experience. Nevertheless, a unidimensional representation of consciousness fails to account for the variety of qualitatively different experiences in both normal and altered states of consciousness. To overcome this problem, cognitive and abstract multidimensional models of consciousness have been proposed, but such dimensions are interdependent and lack axiomatic support. A novel multidimensional characterization of consciousness based on the brain's macroscale functional geometry provides an alternative, empirically grounded model whose dimensions are defined by neurofunctional rather than behavioural attributes. The state of consciousness is then represented as a point in this functional multidimensional space. (shrink)