Experts have been arguing for a while about whether plants have some level of consciousness or not. For example, if a tree is cut down, does it feel sadness or pain, and can it comprehend any kind of reason for such feelings? A new study which tried to answer that question suggests there’s no such thing as plant consciousness.
According to the study published in the journal Trends in Plant Science, researchers Todd Feinberg and Jon Mallat explored the evolution of plants and plant consciousness. The study adds to and compares other studies that focused the complex structures of animal brains. This study draws on the conclusions from those previous studies.
“Feinberg and Mallatt concluded that only vertebrates, arthropods, and cephalopods possess the threshold brain structure for consciousness. And if there are animals that don’t have consciousness, then you can be pretty confident that plants, which don’t even have neurons—let alone brains—don’t have it either,” Lincoln Taiz of the University of California at Santa Cruz said in a statement.
Scientists have been curious about whether plants can think, learn or consciously choose their actions since plant neurobiology was established as a scientific field in 2006. Taiz was one of the researchers who argued against plant consciousness.
“The biggest danger of anthropomorphizing plants in research is that it undermines the objectivity of the researcher,” Taiz said. “What we’ve seen is that plants and animals evolved very different life strategies. The brain is very expensive organ, and there’s absolutely no advantage to the plant to have a highly developed nervous system.”
Plant neurobiology focuses on drawing parallels between electrical signaling detected in plants and nervous systems in animals. The Feinberg-Mallatt model of consciousness shows the organizational complexity of the brain which is necessary for the ability to make subjective decisions.
The electrical signals in plants are used in two ways. The first includes the distribution of electrically charged molecules that travel through the membranes. The second is used to send messages through the organism. For examples, leaves may curve because of the way ions move through the plant’s water reservoir out of its cells, causing their shape to change.
“I feel a special responsibility to take a public position because I’m a co-author of a plant physiology textbook,” he said. “I know a lot of people in the plant neurobiology community would like to see their field in the textbooks, but so far, there are just too many unanswered questions.”
Taiz and his team hope to continue research on plant consciousness and answer more questions about the neurobiology of plants. They plan to use stricter experiments to test whether plants are conscious or not in different conditions.