## 2 Materials and Methods
### Cognitive Performance
#### 2.5.2 Methodological Challenges and Inconsistent Findings in Research  
[PERSON] et al. analyzed 41 studies examining the impact of RF-EMF radiation on cognitive functioning in human beings [29]. They found that the lack of standardized methods in bio-electromagnetic research may have contributed to the high variety of findings [29]. These methodological issues include differences in samples and population size, experimental design, and exposure conditions. The authors also claimed that a reliable tool for assessing changes and fluctuations in cognitive functions due to RF-EMF exposure is yet to be developed. In the future, studies should concentrate on identifying a consistent exposure protocol and sensitive tasks to measure the implications of RF-EMF on cognitive performance, particularly in kids. Furthermore, it is crucial to explore the long-term consequences of RF-EMF exposure on human brain activity. [PERSON] et al. conducted another controlled exposure experiment to investigate the effects of signals similar to those from UMTS base stations on generalized cognitive function in healthy people with and without self-reported RF-EMF sensitivity [22]. The study employed a randomized, double-blind crossover design, exposing participants to 45-minute weekly sessions at 0, 1, or 10 V/m electric field strength. The results indicated no substantial association between exposure levels and well-being or perceived field strength in both groups. Additionally, the authors observed only two marginal effects on cognitive performance at 10 V/m, and peak spatial absorption was significantly lower in brain tissue than while using a cell phone. Overall, under the specified exposure levels, the study found no indication of a deterministic link between RF-EMF and detrimental cognitive effects. [PERSON] et al. conducted experiments to examine the implications of EMF generated by mobile phones on human cognitive performance [33]. The authors concluded that being exposed to signals of the GSM type did not lead to any harmful effects on health, and some studies even suggested that it may improve cognitive performance in adults and children [33]. [PERSON] et al. reviewed recent studies that examined the possible impact of RF-EMF released from cell phones on human cognitive abilities [30]. While previous research suggested no significant short-term impact on cognitive function, newer studies revealed potential detrimental effects correlated with mobile phone EMF exposure. These effects include an increase in cortical excitability in certain brain regions, which may lead to a faster reaction time. However, there are inconsistencies in the findings, and the impacts of longer-term EMF exposure released by mobile phones on brain function remain unclear. The authors conclude that more prominent research findings are required to fully understand the functional implications of the observed results of MP EMF exposure on human cognitive capacities. [PERSON] et al. carried out a study to examine the implications of MP exposure on human cognitive performance in teens over a year [34]. The authors found that an increase in exposure to SMS and voice calls was correlated with fluctuations in cognitive response time, but only in participants who had lower usage at the beginning of the study, indicating that these fluctuations may be the result of statistical regression to the mean rather than cell phone radiation. The Stroop color-word test did not reveal any associations with mobile phone exposure. In a study, [PERSON] et al. examined how the electromagnetic radiation from a typical GSM phone at 890 MHz affected people's cognitive abilities. The motivation of the study was to identify the relationship between exposure to a particular brain region and the cognitive processes connected to that region [35]. The findings demonstrated that exposure toward the left side of the brain led to a delayed left-hand reaction time in three of the four cognitive tasks, with just one of the tests being highly significant.