Academics at The University of Western Australia have discovered that our visual system can estimate number, just as it can guess size or speed. And they believe we see number in the same way we see colour and shape, and that other species, even bees, can do so too.
These findings, by Emeritus Professor John Ross and Dr David Burr (visiting from Florence), appear in their article, "A Visual Sense of Number", to be published in the prestigious, high-impact international science journal, Current Biology, next week (March 25).
Until now, our capacity for understanding numbers has been seen as a cultural invention unique to humans, dependent upon language, Prof Ross said.
"But the ability to distinguish between different numbers of objects, regardless of what the objects are or how they are arranged, has now been proven to exist in infants before they can speak and in many other species, including bees," he said.
"Another recent discovery is that our brains and that of other species seem to be wired to handle numbers. Particular nerve cells in the brain report the presence of a particular number of objects, so that the brain knows how many objects an observer is looking at.
"The latest guess, based on all the recent evidence, is that a primitive number system is present early in life in many species and is the base on which our symbolic systems for representing and manipulating numerical quantities are built. In other words, it is the base for nothing less than mathematics, science and technology."
Ross and Burr's discovery is that the basic building blocks of numerical abilities and arithmetic have their roots in a basic perceptual process.
"We can literally see number, just as we see colour and shape. This would explain why we share the capacity to handle numbers with many other species. Our visual system has much in common with the visual systems of many other species because we have all evolved in slow stages from common ancestors," Prof Ross said.
"Our experiments have identified something - a new visual property - that is of great importance not only to visual science, but also to the emerging field of mathematical cognition."