William Ronald Schafer FRS (born August 29, 1964) is a neuroscientist and geneticist who has made important contributions to understanding the molecular and neural basis of behaviour.

He has made significant discoveries on the functional properties of ionotropic receptors in sensory transduction and on the roles of gap junctions and extrasynaptic modulation in neuronal microcircuits.

More recently, he has applied theoretical ideas from network science and control theory to investigate the structure and function of simple neuronal connectomes, with the goal of understanding conserved computational principles in larger brains.

They first used an automated tracking microscope to record C. elegans behaviour over many hours and measure the timing of egg-laying; these experiments showed that worms fluctuate between behavioral states controlled by serotonin.

[13] More sophisticated worm trackers were later used to generate high-content phenotypic data for other behaviors such as locomotion;[14][15][16] this approach has proven very useful for precisely measuring and classifying effects of genes on the nervous system.