In this article, we explore the impact of presentation rate on the extraction of hierarchical structure by manipulating the duration of the Response-to-Stimulus Interval (RSI) in a Serial Reaction Time (SRT) task. Multiple hypotheses have been put forward in the literature to account for the influence of RSI duration on sequence learning in the SRT task (Frensch & Miner, 1994; Huang et al., 2017; Willingham et al., 1997). However, this question has never been addressed from the perspective of hierarchical structure extraction. We found that RSI duration affected hierarchical elaboration in a non-linear way, with participants building higher hierarchical structures with an RSI of 250 ms compared to RSIs of 1000 ms and 100 ms. This finding suggests the presence of an optimal temporal window for sequence learning in the SRT task. This U-shaped effect cannot be accounted for by any of the existing hypotheses on the influence of RSI duration on sequence learning in the SRT task. We hypothesized that this effect results from the tension between the cognitive system's limited encoding capacity and the amount of information per unit of time delivered to the system.