Plants are not conscious, whether you can ‘sedate’ them or not

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Plants are not conscious, whether you can ‘sedate’ them or not

About two weeks ago, the New York Times ran a story on a scientific paper about how anesthetics stopped motion in plants with a provocative headline for readers and scientists: “Sedate a Plant, and It Seems to Lose Consciousness. Is It Conscious?” The article considers the idea at length, talking about “signs of plant intelligence” and comparisons with animals. But the answer, unreservedly, is “no.” The question of plant consciousness, intelligence, or cognition, has excited and exasperated scientists for more than a century. The very first suggestion of conscious plants was raised by the acclaimed Indian physicist and biologist, J.C. Bose , who first demonstrated in the early 20th century that plants moved in response to various stimuli. Bose is more famously known for his pioneering work on the modern radio, but in a series of experiments reported in his book, Response in the Living and Non-Living , he performed very similar research to what the Times described. In 1902, Bose treated a radish with chloroform and recorded how the plant stopped responding to physical vibrations in a manner analogous to animal nerve cells. He presented these and other results as proof of a “parallelism” between plant and animal “nervous” systems , and later even claimed that plants could “feel pain.” In the 2017 paper recently described in the press, scientists reported, in much more detail, a similar depression in the movements of the Venus fly-trap and the touch-me-not plant ( Mimosa pudica ) upon exposure to diethyl ether and lidocaine, two varieties of anesthetic. While the scientific paper, published in the Annals of Botany last December, claimed that the purpose of the experiment was to study how anesthetics work on cellular mechanisms, media reports concentrated on “plant consciousness” and alleged similarities between plants and humans. Conscious or not In fact, Stefano Manusco and František Baluška, the lead scientists behind the 2017 paper, are famous in botany circles for espousing the idea of “ plant intelligence .” In a 2006 article in the journal Trends in Plant Sciences, they and other colleagues announced a new field of inquiry called “plant neurobiology.” That article was controversial, prompting a sharply written rebuttal by 36 renowned plant biologists, who suggested the field was “founded on superficial analogies and questionable extrapolations” – strong words for an academic debate. Scientifically and methodologically speaking, I cannot find much to fault with either Bose’s work or the recent paper. But the majority of plant scientists would, I think, agree that to draw any conclusion about “consciousness” from this experiment, as the Times would have us do, is tricky at best. The Times was all but alone among top-tier outlets in framing this paper as a question of plant “consciousness.” Ars Technica kept to the simple facts of cells and anesthesia, and Scientific American clearly ended its story , “No one is saying that plants are conscious.” The Times, for its part, only quoted one scientist – Baluška – without presenting any outside or dissenting voices. It […]