Plant Psychology: Touch Me Not Please!
When Prof. Leslee taught us about the concept of Habituation and Sensitization, the first thing came to my mind was the Mimosa Pudica (a.k.a Touch Me Not Plant!). But unfortunately, these concepts were discussed only on the basis of animal learning perspective. So I thought to put my thoughts here and explore a bit of the world of plant psychology.
Plant psychology was found to understand the possibility of learning without a nervous system or neural nets and to see whether the animal learning paradigms can be generalized to plant kingdom as well. Mimosa pudica seems most suitable for such plant learning experiments as it can respond almost instantaneously towards any external stimulus. I think habituation and sensitization are pretty well suited for plant learning as they are fundamental behavior aspects of non-associative learning albeit not so interesting as showing a plant pulling a lever for water.
For a second you might think does plant really needs learning? All they do is simply stand at one place for their whole life while animals need to constantly learn and adapt to their environment as they need to move to survive. But animals or not all life need a means to survive and protect themselves from harmful predators and plants are not an exception. The curling of the effect of Mimosa pudica is an evolutionary behavior that is highly ingrained in their genes as it might have helped them survive. But this survival comes at a cost as curling reduces their ability to produce food via photosynthesis by around 40% which could be a do or die situation for them! This requires learning to recognize different stimuli under varying environments and experiments have shown that touch-me-not indeed learns to do so [Gagliano et al].
As a kid, ‘Lajwanti’ (another name for the same plant) had fascinated me for days whenever I used to play in my garden. The way it curled its leaves differently every time and the moment it unfurled them after observing it for so long was so damn satisfying. It was the only plant I had seen at that time which could respond to my actions and that too in a way which closely resembled my introvert personality. Perhaps that was the reason why this particular memory was invoked in the first place!