Subscribe now

Life

The radical new experiments that hint at plant consciousness

It’s a wild idea, but recent experiments suggest plants may have the ability to learn and make decisions. Are the claims true and if so, what does it mean for our understanding of consciousness and the human mind?

By Natalie Lawrence

24 August 2022

New Scientist. Science news and long reads from expert journalists, covering developments in science, technology, health and the environment on the website and the magazine.

Antonio Sortino

MANY people have seen the way a Mimosa pudica plant, also called the touch-me-not, folds its leaves when they are touched. Fewer know that if you put one into a sealed chamber with a dose of anaesthetic, it will eventually stop doing this, as though it has been knocked out or put to sleep.

The anaesthetic needn’t be special. Diethyl ether, an old-school general anaesthetic, works well. Lidocaine, a local anaesthetic favoured by dentists, is also effective when applied at the roots. What’s more, if you attach electrodes to the surface of the leaves at the same time, you will see that the waves of electrical activity that usually spread through the plant’s tissues are suppressed. These effects aren’t confined to Mimosa pudicaall plants are probably susceptible to anaesthesia, it is just that the effects are more dramatic in fast movers like Mimosa plants and Venus flytraps.

Paco Calvo at the University of Murcia in Spain has done this trick several times in front of audiences. It never fails to surprise onlookers, prompting them to ask the very questions he himself is trying to answer. If plants can be “put to sleep”, does this mean they exist in a state of awareness that is shut off by anaesthetics? Might we consider this state to be a kind of sentience, a subjective internal experience? If so, do plants have some form of consciousness? These are controversial ideas, but Calvo and a small group of plant behaviour researchers take them seriously. Their findings so far, though tentative, could disrupt our understanding of consciousness – not to mention our attitudes towards plants.

Plants…

Sign up to our weekly newsletter

Receive a weekly dose of discovery in your inbox! We'll also keep you up to date with New Scientist events and special offers.

Sign up

To continue reading, subscribe today with our introductory offers

View introductory offers

No commitment, cancel anytime*

Offer ends 2nd of July 2024.

*Cancel anytime within 14 days of payment to receive a refund on unserved issues.

Inclusive of applicable taxes (VAT)

or

Existing subscribers

Sign in to your account