Imagine your left brain hemisphere as an overzealous press secretary who never says “I don’t know.” Even when caught in a complete nonsense, it will conjure up a theory in an instant that you will come to believe. This mechanism, discovered through patients with split brains, is known as the interpreter. Today, as we increasingly rely on LLMs (Large Language Models), this same internal storyteller is working overtime, attempting to make sense of results that often have little to do with reality.
The Chicken, the Spade, and the Great Confabulation
It all began with patients whose corpus callosum was severed to alleviate severe epilepsy, effectively cutting the main information highway connecting both hemispheres. Michael Gazzaniga and Roger Sperry conducted an experiment that remains a neurobiological “hit” to this day. One patient was shown two images: the left eye saw a snowy landscape, while the right saw a chicken’s claw. When asked to select matching images, his hands pointed to the spade and the chicken.
The problem arose when he was asked, “Why?” The left hemisphere (the one that speaks) only saw the chicken. It had no knowledge of the snow that its right neighbour had seen. Rather than admit ignorance, the brain quickly generated a justification: “The spade is needed to clean the chicken coop.” This was not a lie – it was a confabulation, an automatic filling of knowledge gaps with fabricated yet coherent information. Gazzaniga termed this mechanism the “interpreter.” As Manuel Martín-Loeches writes in his book Why Do We Need Intelligence?, for our brain, a coherent narrative is more important than the truth, as it allows us to feel comfortable. Does this resonate with you?
The Right Hemisphere as a Detector of Nonsense
Although the “interpreter” primarily resides in the left side of our skull, contemporary research indicates that our psyche is a constant battle between two systems. While the left hemisphere strives to construct a coherent story at all costs, the right hemisphere acts as the “anomaly detector.” It is the one that says, “Hey, something’s off here; that spade in the chicken coop is a stretch.”
In a healthy brain, these two forces collaborate. The interpreter makes sense of our impulses and emotions, while the anomaly detector ensures we don’t drift too far into the realm of fantasy. Problems arise when the detector is weakened, and we desperately want something to be true. At that point, our internal team of neurons (remember, the brain is a team effort!) begins to accept explanations that are merely “good enough” to keep our spirits up. Sound familiar?
The Digital Interpreter Meets the Human Storyteller
Here we arrive at the point where the chicken and the spade meet your favourite generative language model. When you engage with an LLM, you are interacting with a system that, in a sense, is a “supercharged” interpreter. A large language model does not know what is true. It simply predicts the next word statistically to sound coherent and logical.
However, the most intriguing developments occur not in the programme’s code, but in your mind. When GenAI “hallucinates” (providing false facts in a convincing manner), our human internal interpreter immediately springs into action. We start interpreting the model’s errors as “deep metaphors,” “a specific sense of humour,” or we search for hidden logic that isn’t there. We anthropomorphise algorithms because our brain despises information gaps. If the chatbot responds oddly, your “interpreter” suggests, “I must have phrased the prompt poorly, and it’s trying to guide me.”
As a result, we use LLMs somewhat like Gazzaniga’s patients with the spade – we fabricate a theory to explain a result that is often purely probabilistic rather than a conscious process. The key to wisely utilising AI is not only refining algorithms but also being aware that within our own heads resides a “know-it-all” who will always find justification for the most absurd notion – just to maintain our comfort. Yours, rather than theirs.
Sources:
Manuel Martín-Loeches, Why Do We Need Intelligence? Why Smart People Make Stupid Decisions, JK Publishing, 2024.
Gazzaniga M. S., The Left Brain Interpreter: The Locus of Human Consciousness, 2000.
Self-conducted study in the Consensus tool, Validity of the Left-Brain Interpreter Concept, [accessed: 12.04.2026].
Gazzaniga M. S., Who's in Charge? Free Will and the Science of the Brain, 2011.
