“Remembrance of things past is not necessarily the remembrance of things as they were.”

Marcel Proust

The split-brain experiments, a series of studies that began in the 1950s and 1960s, have provided profound insights into the human mind and its quest for coherence. These experiments involved patients who had undergone corpus callosotomy, a surgical procedure to sever the corpus callosum, effectively splitting the brain into two separate hemispheres. This was done to alleviate severe epilepsy, but it also offered a unique opportunity to study how each hemisphere functions independently.

The findings were fascinating. When the connection between the two hemispheres was severed, each side of the brain began to operate with a mind of its own, so to speak. For instance, when different images were presented to each hemisphere, the patient would only be able to verbalize what was seen by the left hemisphere, which controls speech. However, the right hemisphere, unable to express itself verbally, would still demonstrate understanding through actions^[i].

One of the most intriguing aspects of these experiments was how the mind strives to maintain a sense of continuity. When presented with conflicting information, the brain would concoct stories or reasons to bridge the gap between what was known and what was perceived, showcasing the brain’s inherent need for consistency and order. For example, in one experiment the right hemisphere was presented with a picture with an instruction to perform a task, which the left hemisphere could not see (by presenting it to the left eye). The individual’s left hand (controlled by the right hemisphere) would then indeed perform a task but when when it was asked why the action was performed, the left hemisphere (controlling speech) would concoct a made-up reason for the action, despite not having seen the initial instruction. You read that right: their brain actually made something up! This phenomenon highlights the incredible adaptability and narrative-creating capabilities of our minds.

The split-brain experiments serve as a profound reminder of the subjective nature of our experiences: we do not merely perceive reality as it is, but rather, we experience it through the stories we tell ourselves. Our brains are wired to seek patterns, fill gaps, and create narratives that make sense of the world around us. Our perception of reality is a personal tapestry, woven from the threads of our individual experiences, beliefs, and interpretations.

It’s a humbling thought that what we consider our reality is, in fact, a deeply personal story that our minds construct. As we navigate through life, it’s worth remembering that our truths are often less about the world as it objectively exists, and more about how we piece together the fragments of our experiences into a coherent whole. This understanding can foster empathy and compassion, as we recognize that others live within their own stories, just as vivid and real as our own. Furthermore, it teaches us a valuable lesson that we are not our history.

^[i] Roger Sperry’s Split Brain Experiments (1959–1968) | Embryo Project Encyclopedia (asu.edu)