# A Wireless EEG System for Neurofeedback Training
## 7 Conclusions  
The EEG acquisition system maintained significant savings due to its development of the presented low-cost modular board amplifiers. The proposed design allowed easy adaptation to various NF-EEG task applications, being scalable in regard to spatial and temporal resolutions. In this application designed for children in an outdoor environment, the need for an autonomous wireless system, research, and recording capability for NF information processing was evident. In the school-based setting of the children's study, this system was small and portable with low power consumption for long-term operation. The EEG system had sufficient computing ability for online data transfer, processing, supported streaming, and event detection modes during various complex tasks.  
The stimulated qEEG z-NF brain self-regulation of determinative brain regions has also been shown at the behavioral level to be more effective than NF regulation of a single brain area. An outcome of combined qEEG z-NF-VT training was functional brain reorganization and emerging neuoplasticity [2; 36; 53]. Through specific visual tasks (VTs), the qEEG z-NF alpha-theta network better affected other frequency networks related to the reading and transferred the learned effect to improvements in cognitive and reading abilities by strengthening weakly connected brain areas. Stimulating the dyslexia-unaffected remote brain areas in the ventral route by training can facilitate the affected regions in the dorsal route and hemispheric laterality.  
The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/app13010096/s1](https://www.mdpi.com/article/10.3390/app13010096/s1)]([https://www.mdpi.com/article/10.3390/app13010096/s1](https://www.mdpi.com/article/10.3390/app13010096/s1)), Table S1: Psychological results, \"References [54; 55; 56; 57; 58; 59; 60; 61] are cited in the Supplementary Materials\". Table S2: Behavioral results. Supplementary Materials: Visual training tasks, \"Reference [33] is cited in the Supplementary Materials\".  
Conceptualization, methodology, and supervision, J.D.; device design, [PERSON] ([PERSON]); software and visualization, T.T. ([PERSON]) and T.T. ([PERSON]); validation, [PERSON] ([PERSON]), J.D. and T.T. ([PERSON]); formal analysis, [PERSON] ([PERSON]); investigation and resources, J.D. and T.T. ([PERSON]); writing--preparation, review, and editing, J.D. and T.T. ([PERSON]). All authors have read and agreed to the published version of the manuscript.  
National Science Fund of the Ministry of Education and Science, grant number DN05/14-2016 and Ph.D. grant 2020/2023 funded the research. Ph.D. grant 2022/2023 funded the APC.  
This study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the Institute of Neurobiology, the Institute for Population and Human Studies, BAS (protocol code N\({}^{\circ}\) 02-41/12.07.2019) on 12 July 2019, the State Logopedic Center, and the Ministry of Education and Science (approval N\({}^{\circ}\) 09-69/14.03.2017) on 28 March 2017.  
Informed Consent Statement: Informed consent was obtained from all subjects in the study.  
The data are not publicly available due to the restrictions applied to the availability of the data.  
The authors declare no conflict of interest.
1. (U1, U2) AFEs: the ADS129x comprised eight programmable gain amplifiers (PGAs) with low noise and analog-to-digital converters (ADCs) with high-resolution, auxiliary single-ended differential input modes, a temperature sensor, an ADC delta-sigma modulator, test signals, built-in right leg drive (RLD) amplifiers, lead-off detection, Wilson central terminal (WCT) amplifiers, and built-in reference voltage;
2. (U3) Microcontroller PIC18F2420 (on-chip VCO system frequency range 16-40 MHz; F max = 16.36 MHz/V);
3. (U4) Transmitter-receiver part NRF24L01: the FIFO data stored the transmitted (TX FIFO) or received payloads ready for shutdown (RX FIFO). Both modes (PTX and PRX) allowed the FIFOs access.