Title : Plant sound perception as a window into plant cognition
Abstract:
A growing handful of empirical studies suggests that plants are capable of perceiving ecologically relevant sounds, including the sounds of pollinators, water, and herbivores. The evidence points to adaptive plant behaviors in response to these sounds. Specifically, the studies demonstrated that Oenothera drummondii enhanced the sweetness of their floral nectar within a few minutes of exposure to airborne recordings of a honeybee, that pea seedlings directed the growth of their roots towards the sound of water, and that Arabidopsis thaliana and tobacco plants increased concentrations of their chemical herbivory defenses in response to caterpillar chewing vibrations transmitted to their leaves. While these studies imply that plants are sensitive to sound, what exactly they tell us about the cognitive capability of plants is highly debatable. Are the plant behaviors observed in these studies indicative of cognitive capacity or are they merely environmentally triggered, epigenetic responses? Throughout the sciences and the humanities, it is typical to conceive of plants as biological automatons triggered to perform adaptive responses in the presence of salient environmental features. However, in capturing traits often associated with cognition, such as flexibility, anticipation, and goal-directedness, I argue that sound perception research may be a window into the cognitive abilities of plants. Moreover, I suggest researchers adopt a cognitive framework when designing plant sound perception experiments in order to maximize the potential, derivable insights into plant cognition. Designing plant experiments with a cognitive framework does not require a priori commitment to plant cognition, but it allows for the hypothesis of plant cognition and, thereby, for the potential of observing cognitive behaviors that may otherwise bypass detection.
