**4. Surgical resection strategy**

The intraoperative mapping technique involves selecting the tasks in relation to preoperative assessment, the operative tools, the neurophysiologic parameters and the consequent strategy, i.e., the way we combine them in a clinical situation. Taken together, these costly and time consuming procedures point to the importance of methods and surgical strategy.

One substantial limitation to clinical comparative inference is that multiple cortical or subcortical sites are manipulated during an operation making it impossible to relate one event to the manipulation of one site. In other words, when forced to face a number of methodological issues, it is likely that surgical strategy will improve. Choices regarding positioning, surgical technique, tumor definition, clinical and intraoperative information, functional studies, intraoperative tools, all together will favor a good result. In contrast, consideration of only one or a few functional variables may be confounding. This is why research studies should be validated in the clinical setting, taking into account additional variables critical for this purpose (Sawaya et al., 1998). Furthermore, the challenge of AS and cognitive mapping is the working team, i.e., to what extent individual proficiency can contribute to a clinical purpose when working in a group.
