In the early days of split-brain research, the anatomy of the corpus callosum, the wide band of nerve fibres connecting the two cerebral hemispheres, was noted as early as the late 18th century by anatomists like Félix Vicq-d’Azyr (1784), but it wasn’t until the mid-20th century that scientists began to explore what happened when that connection was severed, initially through experimental corpus callosotomy to treat severe epilepsy in the 1940s by William P. van Wagenen and colleagues and later by neurosurgeons including Walter Dandy who reported partial sections in 1936. However, these early operations did not yet illuminate the cognitive consequences of disconnection. The modern era of split-brain research began in earnest in the late 1950s and early 1960s when Roger W. Sperry and his colleagues (including Michael S. Gazzaniga and Joseph Bogen) at the California Institute of Technology designed systematic experiments on animals and human patients with severed corpus callosi to test how each hemisphere functions independently, culminating in classic work such as their 1962–1967 studies showing that each hemisphere could perceive and remember information that the other did not access and that the left hemisphere was specialised for language while the right excelled in nonverbal tasks. Sperry was awarded the 1981 Nobel Prize in Physiology or Medicine for these discoveries.

From a Christian theological perspective, this research can be seen as revealing the complexity of God’s creation, where the human brain, “fearfully and wonderfully made” (Psalm 139:14, NIV), has distinct yet integrated parts that together enable the fullness of human experience. Even when physical unity is disrupted, the inherent dignity of the person remains because, in Christian thought, the soul is indivisible and not confined to neural tissue (cf. Matthew 10:28), reminding us that neuroscience and faith need not be in conflict but can together deepen our reverence for the Creator’s work in each individual. Importantly, recognising the lateralisation of function and the adaptability of the brain has practical value for personal wellbeing, helping clinicians tailor therapies for neurological and learning disorders and empowering individuals to understand and work with their cognitive strengths, and for societal health by informing educational practices, neurorehabilitation, and compassionate care for those with neurological conditions, reflecting the Biblical call to love and serve all members of the body of Christ (1 Corinthians 12:12-27).