Cuttlefish can remember what, where, and when specific events happened – right up to their last few days of life, researchers have found. The results, published this week in the journal Proceedings of the Royal Society B, are the first evidence of an animal whose memory of specific events does not deteriorate with age.
Researchers from the University of Cambridge, U.K., the Marine Biological Laboratory (MBL), Woods Hole, Mass., and the University of Caen, France, conducted memory tests with 24 common cuttlefish, Sepia officinalis. Half of them were 10-12 months old – not-quite adult, and the other half were 22-24 months old – equivalent to humans in their 90s.
“Cuttlefish can remember what they ate, where and when, and use this to guide their feeding decisions in the future. What’s surprising is that they don’t lose this ability with age, despite showing other signs of ageing such as loss of muscle function and appetite,” said first author Alexandra Schnell of the University of Cambridge’s Department of Psychology, who conducted the experiments at the Marine Biological Laboratory in collaboration with MBL Senior Scientist Roger Hanlon.
As humans age, they gradually lose the ability to remember experiences that happened at particular times and places – for example, what we had for dinner last Tuesday. This is termed episodic memory, and its decline is thought to be due to deterioration of a part of the brain called the hippocampus.