Just Noticeable

This project traces how nineteenth-century Fechnerian psychophysics, an approach to measuring the point at which a difference in stimuli was ‘just noticeable’, was adapted into the sensorial sciences in the U.S. and Europe during the early to mid-twentieth century. These techniques have since been incorporated into the study and management of the quality of air, water, and foods, with the ‘just noticeable’ threshold coming to stand in as an estimate of acceptability in the absence of toxicological data. This project uses the methods and approach of history of technology, environmental history, and food studies. I will examine the tools, techniques, and laboratory spaces where sensing of the just noticeable became codified as a physical form of labor dedicated to making perceptible information scientifically knowable, and traces how the idea of ‘just noticeable’ has come to shape responses to environmental contamination.