Jerusalem, 3 November, 2026 (TPS-IL) — Tel Aviv University researchers have found that plants can experience a form of “optical illusion” when sensing light and determining which direction to grow.
The study found that plants combine light signals detected by receptors distributed along their stems, using nonlinear biological processing rather than simply growing toward the strongest light source.
In experiments, sunflower seedlings exposed to multiple blue-light sources sometimes grew toward a weaker source after two stronger, opposing lights canceled each other’s influence. The researchers developed a mathematical model that successfully predicted the seedlings’ growth direction under different lighting conditions.
The model also predicts slight distortions in the direction plants perceive as receiving more light, although these could not yet be measured directly.
The findings were published in PNAS.