According to conventional wisdom, the split-brain syndrome puts paid to the thesis that consciousness is necessarily unified. The aim of this paper is to challenge that view. I argue both that disunity models of the split-brain are highly problematic, and that there is much to recommend a model of the split-brain—the switch model—according to which split-brain patients retain a fully unified consciousness at all times. Although the task of examining the unity of consciousness through the lens of the split-brain syndrome (...) is not a new one—such projects date back to Nagel’s seminal paper on the topic—the time is ripe for a re-evaluation of the issues. (shrink)

Many contemporary bioethicists claim that the possession of certain psychological properties is sufficient for having full moral status. I will call this thepsychological approach to full moral status. In this paper, I argue that there is a significant tension between the psychological approach and a widely held model of Dissociative Identity Disorder (DID, formerly Multiple Personality Disorder). According to this model, the individual personalities or alters that belong to someone with DID possess those properties that proponents of the psychological approach (...) claim suffice for full moral status. If this account of DID is true, then the psychological approach to full moral status seems to entail that the two standard therapies for treating DID might, on occasion, be seriously immoral, for they may well involve the (involuntary) elimination of an entity with full moral status. This result should give proponents of the psychological approach pause, for most people find the claim that current treatments of DID are ethically suspect highly counter-intuitive. (shrink)

opinionated review of some of the recent work on the phenomenal unity of consciousness.

We observe that approaches to intersubjectivity, involving mirror neurons and involving emulation and prediction, have eclipsed discussion of those same mechanisms for achieving coordination between the two hemispheres of the human brain. We explore some of the implications of the suggestion that the mutual modelling of the two situated hemispheres is a productive place to start in understanding the phylogenetic and ontogenetic development of cognition and of intersubjectivity.

This paper concerns the role that reference to subjects of experience can play in individuating streams of consciousness, and the relationship between the subjective and the objective structure of consciousness. A critique of Tim Bayne’s recent book indicates certain crucial choices that works on the unity of consciousness must make. If one identifies the subject of experience with something whose consciousness is necessarily unified, then one cannot offer an account of the objective structure of consciousness. Alternatively, identifying the subject of (...) experience with an animal means forgoing the conceptual connection between being a subject of experience and having a single phenomenal perspective. (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)