# Progress in the Knowledge, Application and Influence of Extremely Low Frequency Signals
## 3 Results and Discussion
### Community Analysis
The effects are greater shortly after the application of the field and its disconnection, importing more changes in exposure levels than its duration. The study of the interaction of ELF fields and living systems, as well as the risk of developing cancer cells has been extensively researched in the last decade, one example being [57]. The bidirectionality of these signals should also be considered. Studies have been established that consider cancer cells such as glioma or different types of cancers to generate ELF waves. In established studies of glioma patients, epileptic seizures are often seen due to the impact of the tumor on the physiology of the brain. This unexpected electrical activity can disrupt the functionality of the healthy neural network in the vicinity of the tumor mass and may contribute to seizures [79]. Breast cancer is one of the most common cancers worldwide, although its pathophysiology is poorly understood. Numerous single-cell electrophysiological studies have been developed, suggesting a link between bioelectricity and cell invasiveness. A pattern of activity with characteristics like those of random telegraph signal (RTS) noise [80] has also been recorded. A similar fact is observed in prostate cancer, one of the most common cancers in the male population, where its basic biological function at the cellular level is not yet fully known. In [81] the measurement and characterization of the electrical activity of PC-3 prostate cancer cell populations is presented, demonstrating for the first time the existence of a significant electrical pattern. This type of recording allows for the establishment of new, highly sensitive, real-time research pathways for the development of new, more-specific, and effective treatment strategies. In the 2000s, reviews appeared that studied the electrophysiological and cognitive effects in humans after exposure to this type of ELF field as well as to radio frequency (RF) waves and the microwave frequency of mobile phones. One of these works is [75, 82], the second in node importance in this community. The conclusions of this document expose the lack of unification of the beneficial or harmful effects against exposure to low intensity ELF electromagnetic waves. The author of this work, [PERSON], published another paper that studied the temporal evolution of physiological and cognitive effects derived from exposure to ELF magnetic fields and ELF-modulated radiofrequency fields. [82] reviews studies using techniques such as electroencephalography, event-related potentials, and positron emission tomography to investigate the effects of the electromagnetic field on human physiology and various measures of performance (cognitive, perceptual, behavioral). It also discusses the possible variables that are often not considered in human bioelectromagnetic studies, such as personality, individual differences, and the specific laterality of the ELF magnetic field and exposure to mobile phones on the brain. This review suggests that brief exposures may induce measurable changes in the electrical activity of the human brain, particularly in the region of alpha frequencies (8-13 Hz) over the posterior regions of the brain. Similar results are presented in [83], a publication that is among the 10 most-important nodes. It studied the effects of ELF sinusoidal magnetic fields (45 Hz) considering the EEG spectral analysis. It was observed that the average frequencies and the peak of the EEG increased in the frontal leads and that most of the changes were due to intermittent exposure, while a continuous exposure produced unimportant changes. The most significant effects are presented in the physiological measures, compared to the effects on performance, and it is possible that the behavioral measures are not sensitive enough to detect changes in brain function. The effect of pulsed-ELF magnetic fields on the electrical activity of the human brain has also been considered [84]. The analysis of the results revealed a significantly higher occipital alpha activity.