What was once just believed to be a trait in humans is now being thought to be widespread throughout the entire animal kingdom: creating false memories. Researchers at Queen Mary University in London have shown for the first time that insects can also create false memories.
The same is likely true for mice. During a 2013 study, scientists at MIT induced false memories of trauma in mice, and the following year, they used light to manipulate mice brains to turn bad memories into good ones.
Using a classic Pavlovian experiment, co-authors Kathryn Hunt and Lars Chittka determined that bumblebees sometimes combine the details of past memories to form new ones, Christian Science Monitor reported. The findings were published today in Current Biology.
“I suspect the phenomenon may be widespread in the animal kingdom,” Dr. Chittka said in a written statement to the Monitor.
To start, Chittka and Dr. Hunt trained the bee subjects to expect a reward if they visited two artificial flowers – one solid yellow, the other black-and-white rings. The order didn’t matter, as long as the bees visited both flowers. In subsequent tests, they would present a choice of the original two flower types, plus one new one. The third type was a combination of the first two, with yellow-and-white rings. At first the bees consistently went to the original two flowers, the ones that offered a reward.
Things then shifted. One to three days after training, the bees became confused and started incorrectly choosing the yellow-and-white flower up to half of the time. They seemed to associate that pattern with a reward, despite having never seen it before. The bumbles ended up combining the memories of two previous stimuli to generate a new, false memory.
“Bees might, on occasion, form merged memories of flower patterns visited in the past,” Chittka said. “Should a bee unexpectedly encounter real flowers that match these false memories, they might experience a kind of deja-vu and visit these flowers expecting a rich reward.”
“In bees, for example, the ability to learn more than one flower type is certainly useful,” Chittka added, “as is the ability to extract commonalities of multiple flower patterns. But this very ability might come at the cost of bees merging memories from multiple sequential experiences.”
Chittka has studied bumblebee’s memory for two decades. Bees can be raised and kept in a lab setting, making them ideal long-term test subjects.
“They are [also] exceptionally clever animals that can memorize the colors, patterns, and scents of multiple flower species – as well as navigate efficiently over long distances,” Chittka said.