Humans whose corpus callosum has been surgically severed – “split-brain” humans – have received the lion’s share of attention in unity of consciousness research. Two dominant views have emerged: one-stream views according to which split-brain consciousness is wholly unified, and two-streams views according to which split-brain consciousness is wholly disunified. A third option involving violations of the transitivity of co-consciousness, the partially unified stream view, has seemed to theorists…
Read moreHumans whose corpus callosum has been surgically severed – “split-brain” humans – have received the lion’s share of attention in unity of consciousness research. Two dominant views have emerged: one-stream views according to which split-brain consciousness is wholly unified, and two-streams views according to which split-brain consciousness is wholly disunified. A third option involving violations of the transitivity of co-consciousness, the partially unified stream view, has seemed to theorists conceptually problematic and empirically unsettled. This paper offers a new argument for the partially unified stream view based on a different population of humans whose corpus callosum never developed in the first place – congenitally acallosal humans. It proposes a “fine-grained” account of the structure of acallosal consciousness on which highly determinate contents, but not broad psychological capacities, are disunified.
