Clare Hewitt
Behaviour to Remember
If you’ve ever encountered a Mimosa pudica (translated as sensitive plant), you might have touched or shaken its leaves to see them transform, folding inwards in response. In 2011, ecologist Dr Monica Gagliano conducted an experiment to explore whether the Mimosa pudica’s tendency to droop when perceiving threat was an instinctual reflex or if the plant could, “truly learn from new experiences and flexibly alter her behaviour.” (page 59 from her book Thus Spoke the Plant). Gagliano thought that to do so would indicate the plant’s presence of memory and ability to learn. She performed 15 centimetre controlled drops on the plants in a variety of scenarios. As expected, when initially dropped, the plants responded by closing their leaves. However, after four to six drops, each plant stopped folding and continued this way for a total of 60 drops. They had learned there was no apparent threat and it was unnecessary to reduce their capacity to forage for light. Importantly, when Gagliano repeated the experiment three days later, each plant kept their leaves open from the first drop onwards.
3
Controlled drop system for habituation training of Mimosa pudica plants (Gagliano)
As human beings, we commonly associate memory with brain-wide processes of encoding, storage and retrieval. Gagliano views it differently, stating: “Because memories are born of and come into existence within and through relationships of all kinds...I saw memory as a feature of a truly ecological, dynamic process of relationships, where meanings emerge to shape the production of behaviours that, in turn, shape new interactions for new meanings to emerge.” (page 67, Thus Spoke the Plant).
