Mary Gates Endowment For Students

Srinidhi Naidu

Mary Gates Research Scholar, Winter 2023


Research Project: Dynamic Large-Scale Population Encoding of Motion in Low-Light Conditions Indicate High Temporal Precision in Star-Light Levels.

Research Project Description: Sensory signal processes– specifically how visual systems perform– function under the limits imposed by physics. One such physical limit comes in the detection of light. Light is divided into discrete amounts of energy called photons. Because of this division, light is inherently variable and operates under such variance sets on the retina. Understanding how a population of cells in the retina work together to detect and encode the motion of moving objects during a given time interval is pertinent to unraveling the internal mechanisms of the retina. This property is fundamental across varying light levels to understand visual adaptation in low-light conditions. So far, the only thing studied in low light is if our system can detect the existence of a flash or dim light, but not deduction of movement and time information. A key tool in studying this is flicker fusion frequency. Flicker fusion is the frequency at which flickering light is perceived as continuous– through studying varying light levels, we can directly study sensitivity to the timing of different frequencies (temporal resolution). Through measurements of the flicker fusion frequency, rod cells have been understood historically as having extremely poor temporal resolution. This suggested that the ability to detect moving objects– which relies on timing information– would be poor at low light levels. Through extracellular electrophysiological experiments conducted using a 512-channel multi-electrode array, we recorded the electrical activity of neural firing from a population of at least 5000-1000 retinal ganglion cells in the primate retina to show that there is high temporal precision in star-light levels due to compensatory mechanisms in the retinal ganglion cells and adjunct circuits.

What have you learned throughout your research/leadership project and experience?

Throughout my research project I’ve learned many experimental and computational skills, but I think the most important thing I’ve learned is how to effectively prioritize my time and manage school, research, and other commitments.

What advice do you have for future Mary Gates Research applicants?

I would advise future Mary Gates applicants to not be afraid to ask for help on your essay from the people in your lab, not just your mentor or PI! Whenever I felt a writer’s block, or was unsure on how to phrase a concept in the scope of my essay, it was helpful to talk through things with members of my lab. Not everyone was familiar with my project, so discussing my essay with them kept me in check to make sure that my essay wasn’t getting too technical or unclear.