Abstract

This paper offers a functional reframing of split-brain phenomena – but not one developed for that purpose. The framework described here was originally constructed to explain core features of brain function: perception, imagination, planning, internal modeling, and subjective access. Only once the model was complete did it become clear that it also accounted – with striking precision – for the puzzling dissociations observed after callosotomy. That unplanned alignment lends weight to the structure itself. To frame this model, we treat the brain as a functional whole – what we call the brain at large – understood as a global cybernetic system responsible for goal formation, environmental modeling, and behavioral control. Within this system, we identify a specialized subsystem: the proxy transfer device (PTD), a lateralized expressive mechanism whose activity is reused internally (a process called looping) to enable reportable awareness. This functional distinction between the PTD and the broader brain at large proves critical for resolving long-standing puzzles in split-brain research and clarifying the architecture of conscious experience. Beyond reinterpreting past data, the framework points toward a new line of research: identifying the difference between looped and unlooped responses. It proposes that what we call “consciousness” corresponds, functionally, to internal looping – a learned reuse of the expressive pathway that gives the brain a new internal resource that is highly effective for many purposes. On this view, split-brain phenomena are no longer peripheral puzzles or strange edge cases; rather, through the lens of the framework, they shed light on central facets of the brain’s operation. (Working Paper – updated February 2, 2026 – the only changes being the inclusion of the last three paragraphs of Section 4, explaining how recent findings also fit within the BAL-looping account.)