Prior behavioral experiments across a variety of tasks have typically shown that the go/no-go procedure produces not only shorter response times and/or fewer errors than the two-choice procedure, but also yields a higher sensitivity to experimental manipulations. To uncover the time course of information processing in the go/no-go versus the two-choice procedures during visual word recognition, we examined the impact of a lexical factor (word frequency) in a lexical-decision task by tracking event-related potential (ERP) waves. If the differences across response procedures influence relatively early lexical processing stages, we would expect word frequency to induce differences across tasks in the early epochs of the ERP. Alternatively, if the differences across response procedures only occur at a postaccess response selection stage, we would only expect differences across procedures in late time windows of the ERP. Results showed that the word-frequency effect occurred earlier (starting around 200 ms poststimuli) in the go/no-go than in the two-choice response procedure. These results support the view of a largely flexible cognitive network in which a subtle manipulation of the response procedure can affect early components of processing.