Existing psychophysiological measures (eg, fMRI, EEG, MEG) are impractical for a large scale behavioral study (N> 1000) due to their exorbitant data acquisition costs. Psychological tests (eg, Emotional Stroop task), which rely on response time and performance accuracy measures, are economical but are too coarse to inform dynamic continuous interactions among perceptual, cognitive, and affective processes. By augmenting standard cognitive tests with choice-reaching measures, the problems inherent in psychological tests can be resolved. Recent revolutionary research in cognitive science has shown that choice-reaching involves a dynamic integration of motivation, action and cognition. This complex interaction of motivation, action and cognition can be examined by analyzing the movement of the computer cursor pixel by pixel every few milliseconds. Open source software and R data analysis library “mousetrap” help researchers to collect mouse-cursor trajectory data relatively easily. With continued interest and innovation, the mouse cursor trajectory method is likely to become a standard procedure for psychological tests, especially for the study investigating individual differences underlying cognitive, affective, and perceptual processing.