Zero is fascinating. Often perceived as an absence, it nevertheless reveals an unexpected complexity. How does the human brain react to this abstract idea?
Researchers have discovered that specific neurons in the brain treat zero as a full-fledged number. But what exactly happens inside our head?
Experiments conducted on neurosurgery patients have measured neural activity in response to numeric stimuli. The results show that zero, far from being just a simple absence, activates specific regions of the brain.
The patients were exposed to both symbolic representations of zero (with the Arabic numeral "0") and non-symbolic ones (an empty set of dots). On a neuronal level, responses varied depending on whether zero was presented as a digit or an empty set. Some nerve cells reacted only to symbolic zero, others only to its non-symbolic version. This indicates a difference in processing depending on the form in which it is perceived.
Thus, zero is integrated into the brain's number line, but with subtle nuances. Indeed, dedicated neurons signal not only zero but also neighboring numbers like "1," although more weakly.
The slowness in recognizing zero suggests a particular cognitive complexity. This process seems to require greater neural resources than other numbers, likely due to the abstract nature of zero and the brain's challenge in interpreting the absence of quantity as a numerical value.
These findings open up perspectives on how our brain structures mathematical concepts. They could also explain the difficulties some children or adults have in mastering this very special number.
Why does the brain react differently to symbolic and non-symbolic zero?
The brain perceives zero in two main forms: symbolic (digit "0") and non-symbolic (empty set). This distinction is crucial because each form activates different neurons. The neurons that respond to symbolic zero treat the digit as information already coded within our usual cognitive systems.
In contrast, non-symbolic zero, like an empty set of dots, requires more neural resources. The brain takes longer to process this visual absence because it must interpret a concrete emptiness and integrate it into the line of countable quantities. This distinction reveals the abstract nature of the concept of zero.
Neuroscientists explain this phenomenon by the lack of sensory experience linked to "nothing." The brain, designed to respond to tangible stimuli, must conceive of an "empty quantity" as a numerical value, which demands a high level of cognitive abstraction.
How is the concept of zero integrated into human history and cognitive development?
Zero is a relatively recent concept in human history. It emerged about two millennia ago, long after the first natural integers. Its introduction marked a turning point in mathematics and philosophy, enabling significant advancements such as algebra and differential calculus.
On a cognitive level, children generally only understand zero from the age of six. This process requires significant neurological development. The child must not only perceive that zero is less than one, but also understand that zero is an abstract concept representing the absence of quantity.
The development of zero in the human mind is complex. It reflects the mind's capacity to conceptualize abstract notions that have no direct equivalent in sensory experience.
Author of the article: Cédric DEPOND