From the Mental State of Noise to the New Frontiers of Cognition

Subsumed under the category of noise, in the context of Fischer Black’s paper on models for trading in the financial markets, is a range of uncertainties pertaining to economic forecasting, uncertainties about future tastes and developments in technology in this instance, or about irrational expectations. However, in terms of economic models alone, the profundity of Fischer Black’s insight goes well beyond the mere question of their efficiency. What he raises is a fundamental epistemological principle pertaining to all theory: noise is what afflicts our ability to test theories. We owe Fischer Black this stark truth of epistemological, ethical, and, dare I say, metaphysical consequence: because of noise, we are “forced to act largely in the dark” (529). Steven Sands and John Ratey’s article of the same year, “The Concept of Noise,” which we are happy to be able to republish here, can cautiously be credited with having first spelled out the cognitive dimension of the predicament to which Fischer Black points as noise. In this article, Sands, then Clinical Instructor in Psychology at Harvard Medical School, and Ratey, Assistant Professor of Psychiatry at the same institution, propose the “mental state of noise” as a key concept transversal to the nosology or classification of psychiatric illnesses: