Split-Brain: What We Know Now and Why This is Important for Understanding Consciousness

Edward H.F. de Haan, Paul M. Corballis, Steven A. Hillyard, Carlo A. Marzi, Anil Seth, Victor A.F. Lamme, Lukas Volz, Mara Fabri, Elizabeth Schechter, Tim Bayne, Michael Corballis, Yair Pinto

Research output: Contribution to journalReview ArticleResearchpeer-review

35 Citations (Scopus)


Recently, the discussion regarding the consequences of cutting the corpus callosum (“split-brain”) has regained momentum (Corballis, Corballis, Berlucchi, & Marzi, Brain, 141(6), e46, 2018; Pinto et al., Brain, 140(5), 1231–1237, 2017a; Pinto, Lamme, & de Haan, Brain, 140(11), e68, 2017; Volz & Gazzaniga, Brain, 140(7), 2051–2060, 2017; Volz, Hillyard, Miller, & Gazzaniga, Brain, 141(3), e15, 2018). This collective review paper aims to summarize the empirical common ground, to delineate the different interpretations, and to identify the remaining questions. In short, callosotomy leads to a broad breakdown of functional integration ranging from perception to attention. However, the breakdown is not absolute as several processes, such as action control, seem to remain unified. Disagreement exists about the responsible mechanisms for this remaining unity. The main issue concerns the first-person perspective of a split-brain patient. Does a split-brain harbor a split consciousness or is consciousness unified? The current consensus is that the body of evidence is insufficient to answer this question, and different suggestions are made with respect to how future studies might address this paucity. In addition, it is suggested that the answers might not be a simple yes or no but that intermediate conceptualizations need to be considered.

Original languageEnglish
Pages (from-to)224-233
Number of pages10
JournalNeuropsychology Review
Issue number2
Publication statusPublished - Jun 2020


  • Consciousness agents
  • Epilepsy
  • Lateralization
  • Split-brain
  • Visual perception

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