In 2008, researchers created human three-dimensional neural tissue – known as the pioneering work of “brain organoids.” In recent years, some researchers have transplanted human brain organoids into animal brains for applicational purposes. With these experiments have come many ethical concerns. It is thus an urgent task to clarify what is ethically permissible and impermissible in brain organoid research. This paper seeks (1) to sort out the ethical issues related to brain organoid research and application and (2) to propose future (...) directions for additional ethical consideration and policy debates in the field. Toward (1), this paper first outlines the current state of brain organoid research, and then briefly responds to previously raised related ethical concerns. Looking next at anticipated scientific developments in brain organoid research, we will discuss (i) ethical issues related to in vitro brain organoids, (ii) ethical issues raised when brain organoids form complexes or have relationships with other entities, and (iii) ethical issues of research ethics and governance. Finally, in pursuit of (2), we propose research policies that are mindful of the ethics of brain organoid research and application and also suggest the need for an international framework for research and application of brain organoids. (shrink)

The problem of phenomenal unity consists in providing a phenomenological characterization of the difference between phenomenally unified and disunified conscious experiences. Potential solutions to PPU are faced with an important challenge. I show that this challenge can be conceived as a phenomenological dual to what is known as Bradley’s regress. This perspective facilitates progress on PPU by finding duals to possible solutions to Bradley’s regress and makes it intelligible why many characterize phenomenal unity in terms of the existence of a (...) single global conscious state. I call this latter view the “single state conception”. SSC is superficially attractive, because it seems to provide a solution to the phenomenological dual to Bradley’s regress, but should still be rejected, because it does not solve PPU; instead, it creates more problems; these problems can be avoided by alternative conceptions of phenomenal unity. (shrink)

: This paper argues for a distinction between possession of a unified consciousness and possession of a single stream of consciousness. Although the distinction has widespread applicability in discussions of the structure of consciousness and of pathologies of conscious experience, I will illustrate its importance primarily using the debate about consciousness in split-brain subjects, suggesting that those who have argued that split-brain subjects have two streams of consciousness apiece and those who have argued that they have a unified consciousness may (...) both be right. (shrink)

According to the Phenomenal Unity Thesis (“PUT”) – most prominently defended by Tim Bayne and David Chalmers – necessarily, any set of phenomenal states of a subject at a time is phenomenally unified. The standard formulation of this thesis is unacceptably vague because it does not specify what it is to be a subject. In this paper, I first consider possible meanings for ‘subject’ as used in PUT and argue that every plausible candidate definition renders the thesis trivially true. I (...) consider and reject Tim Bayne’s proposal that ‘subject’ means ‘human being’. Then I argue, contra Bayne and Chalmers, that PUT is not incompatible with any major theory of consciousness, and contra Michael Tye, that split-brain patients do not provide evidence against PUT. I close by considering some nontrivial alternatives to PUT. (shrink)

Many experimental findings with split-brain subjects intuitively suggest that each such subject has two minds. The conceptual and empirical basis of this duality intuition has never been fully articulated. This article fills that gap, by offering a reconstruction of early neuropsychological literature on the split-brain phenomenon. According to that work, the hemispheres operate independently of each other insofar as they interact via the mediation of effection and transduction—via behavior and sensation, essentially. This is how your mind and my mind interact (...) with each other, however, giving rise to the intuition that a split-brain subject has two minds. (shrink)