In the realm of Human-Computer Interaction, cognitive load (CL) plays a crucial role in determining user satisfaction, product acquisition, and user retention. We are introducing a new type of interface - Infinite Interfaces (II), that dynamically adapts to user inputs and, therefore, offers personalized and efficient user experiences. However, the novelty of such interfaces may lead to increased cognitive effort, as most users are accustomed to traditional predetermined interfaces. This study seeks to evaluate the CL associated with II using two approaches: subjective user ratings, which are simple and accessible, and EEG technology, providing an objective measure. The research aims to compare CL in II versus traditional interfaces, using both methods to identify any similarities or differences in the results. Results indicate that while novel interfaces like II initially induce higher CL, they offer long-term potential for improving user efficiency in complex tasks.