A Study of Habituation Behavior and Pavlovian Conditioning in the 'Mimosa pudica' Plant

Modern study of complex plant behavior rarely utilizes the psychological frameworks that are common in animal research. Behaviorism is an ideal logical framework in constructing an ecocentric foundation of plant behavior because of its objective treatment of behavioral patterns without dependence upon responsible mechanism. Biologists have recently applied Behavioral paradigms to plant learning experiments and found preliminary success, but have also been met with skepticism stemming from incomplete and improper behavioral procedures and human interference and error. This thesis constructed a novel procedural framework and experimental apparatus featuring automated stimulus implementation and rigorous data collection by which Mimosa pudica plant subjects could be left for weeks at a time without human contact. A photo-analysis algorithm that was blind to experimental conditions measured stimulus responses in order to unambiguously demonstrate behavioral trends in data. Experiment 1 established a habituation protocol to an air flow stimulus and found plants to show a monotonic decrease in magnitude of response over 30d of data collection (but required additional controls to fully establish habituation). Experiment 2 implemented a repeated associative contingency between changes in air flow and vibration stimuli and found a systematic difference in unconditioned response magnitude across experimental and control groups over 28d, thereby establishing preliminary, though still unclear, evidence for Pavlovian conditioning in M. pudica plants. Highly regulated environmental conditions, mechanically automated stimuli, and algorithmic response measurement and comparison reduced the possibility for human error and maximized procedural effectiveness in order to create ideal conditions for observations of plant learning.