In addition to recording response time, the program also records whether a response was correct or incorrect. To assure that research participants master the number-color code before generating data, the program sets a performance criterion that must be achieved on practice trials. Once the criterion is met they can proceed to the experiment. Return to Top Procedure Research participants elect the number of trials they conduct but they must complete at least 72 trials for the data to be admissible for inclusion in the PsychExps database. Each trial begins with a pulsating plus sign that serves to establish a focal point on the computer screen.
Research participants press a key when they are ready for a word to be presented.
Following the key press, there is a random delay from 1 to 3 seconds before the word appears. When words appear, they are written vertically on the screen. The central axis of the word is designed to be approximately 3 o of visual angle to the right or left of the fixation point on lateral presentations, though the actual visual angle will vary depending on monitor size and the distance of research participants from the monitor. On central presentations, the word axis is at 0 o relative to the fixation point. Display times are fixed at 150 msec to assure that laterally presented words are experienced in a single visual hemifield.