A computer program product is provided for improving comprehension in rapid serial visual presentation. The product includes a non-transitory computer readable storage medium having program instructions embodied therewith executable by a computer to cause the computer to perform a method. The method includes determining, by a cognitive load estimator, a cognitive load of a plurality of words included in a rapid serial visual presentation by using at least one metric. The cognitive load is determined on any of a word level and a word sequence level. The method includes calculating, by a word presentation rate calculator, a variable presentation rate for the words based on the cognitive load. The method includes controlling, by a rate controller, a displaying of the words on a display in accordance with the calculated variable presentation rate. The rate controller temporarily reduces the variable presentation rate responsive to the cognitive load being above a threshold.