In apes and humans, the prefrontal cortex is the seat of higher-order cognition, allowing us to reason about the world around us. Insect brains are much simpler and lack anything resembling a prefrontal cortex, yet a new study finds that honeybees can learn to differentiate between objects based on their relation to one another, such as “same or different” and “above or below.”
Researchers at the University of Toulouse in France and their colleagues trained bees to enter a Y-shaped maze and travel down one of the arms to receive a reward. At the entrance to the maze, the bees were shown a simple image, such as a circle with black and white vertical stripes. At the fork, each possible path was marked with its own simple image: one path displayed the same vertical stripes, and the other path displayed horizontal stripes. Some bees were rewarded if they crawled down the arm of the maze that was marked with the same stripe pattern as the entrance; others learned to enter the arm that was marked with a different pattern.
After the bees had learned whether “same” or “different” marked the right path, the researchers changed things up—they presented the bees with a colored swatch at the opening to the maze instead of a stripe pattern. At the fork, one path was marked with the same color as the entrance, and the other path was marked with a different color—and the insects continued to choose the correct path, demonstrating that their understanding of same and different carried over to the new stimuli. Similar setups showed the bees could also master the concepts of above versus below and left versus right.
The findings offer insight into the evolution of intelligence. The bees' success suggests that this type of abstract cognition far predates the evolution of the large mammalian brain, according to Aurore Avarguès-Weber, a neuroscientist at Toulouse and co-author of the study published in October 2013 in Proceedings of the Royal Society B. Avarguès-Weber and co-author and colleague Martin Giurfa hypothesize that sociability and navigation skills may give rise to concept learning, which means the ability to think abstractly very likely exists in yet other species with nervous systems entirely unlike our own.