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Brain and the Brainless: Euglena, Perception and Brainwaves

Euglena are algae with photosensory spots. We exposed euglena to various light conditions under a microscope and measured their response. We then extrapolated to human perception before the summer ended.


Joseph Parziale, Yeuming Li, Megan Vetter


Luis Perez Cuesta

Project Period:

2018 Summer



Previous research on the photosynthetic algae Euglena gracilis has shown that Euglena can sense and respond to blue light, and does not seem to sense red or yellow light, due to the properties of its red eyespot. Euglena has only been known to show positive phototaxis when the intensity of blue light is within a critical intensity. To show the effect of blue light on Euglena, both positively and negatively, we used multiple different methods of exposing them to light. We found a strongly negative phototactic response under high-intensity beams of light, such as those from laser pointers or circuit LEDs above 20% brightness. There seemed to be a positive phototactic response when the brightness of the blue LED was lowered to 2%.

This page was originally developed by BioBus Summer 2021 Jr. Scientist William Rhee.

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