Hamilton Institute Seminar

Wednesday, February 12, 2020 - 13:00 to 14:00
Hamilton Institute Seminar Room (317), 3rd Floor Eolas Building

Speaker: ​Dr Constantine Evans, Maynooth University Hamilton Institute

Title: "Pattern recognition in the nucleation kinetics of self-assembly"

Abstract: Phenomena in nature often exhibit computational behavior, with networks of chemical reactions and the growth of crystal structures being two notable examples.  Recent theoretical work has suggested that the nucleation of crystal structures could perform computation as well.  During nucleation, simple, kinetically-unfavorable interactions between components stochastically explore a large state space of possible small assemblies, until some assemblies become large enough that they can act as nuclei for further, kinetically-favorable growth.  The paths to this favorable growth could, in theory, depend not just on the concentrations or properties of individual components in isolation, but also on the patterns and co-localization of components in the many possible nuclei, in a manner similar to neural networks such as Hopfield Associative Memories.

To investigate the natural reality underlying these theoretical findings, we constructed a system of DNA tiles that, depending on an input pattern provided as a 917-dimensional vector of concentrations, will grow different quantities of three different structures, and successfully applied this system to recognize a series of 18 grayscale images.  Our results experimentally demonstrate that the nucleation of crystal structures can naturally perform computation and recognize of patterns in the concentration and interactions of the components involved, showing a new and hitherto-unexplored form of computation in basic molecular processes.