Change rule of brain alpha wave synchronization under different depths of cognitive processing(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第6期
- Page:
- 737-742
- Research Field:
- 医学信号处理与医学仪器
- Publishing date:
Info
- Title:
- Change rule of brain alpha wave synchronization under different depths of cognitive processing
- Author(s):
- DENG Xuan; QIN Yurong; MA Yongxia
- School of Computer, Electronics and Information, Guangxi University, Nanning 530004, China
- Keywords:
- Keywords: depth of cognitive processing steady-state visual evoked potential alpha wave synchronization normalized Shannon entropy
- PACS:
- R318；R338.8
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.06.015
- Abstract:
- Abstract: Visual graphics that can reflect different depths of cognitive processing are used as the stimuli, and normalized Shannon entropy is used as an index for effectively evaluating the phase synchronization of the alpha wave of steady-state visual evoked potentials (SSVEP) and the simulation signals. The correct rate of visual image recognition is taken as the cognitive accuracy. Based on the stimulation frequency of 7-15 Hz and different stimulation intensities (strong, medium and weak, which corresponds to 100%, 50% and 0% of the maximum brightness of the screen, respectively), the relationship between the depth of cognitive processing and SSVEP alpha wave phase synchronization is studied. Within the scope of this study, whether the stimulation intensity is strong, medium or weak, the degree of alpha wave synchronization corresponding to deep cognition is the highest, followed by that corresponding to moderate cognition, and the degree of alpha wave synchronization corresponding to shallow cognition is the smallest. When the stimulation intensity is constant, the degree of alpha wave synchronization at 3 different depths of cognitive processing reaches the highest at the brain spontaneous alpha wave frequency (Individual Alpha Frequency, IAF, around 10 Hz). As the absolute value of the difference between stimulation frequency and IAF increases, the degree of synchronization gradually decreases, showing the law of Arnolds tongue change in the nonlinear synchronization theory. Under the low and medium stimulation intensities, when the stimulation intensity is constant, the cognitive accuracy shows the law of Arnolds tongue changing with the increasing of the absolute value of the difference between stimulation frequency and IAF (the center frequency is IAF). In addition, at medium stimulation intensity, a higher cognitive accuracy is also occurred at 13 Hz. However, when the stimulation intensity exceeded a certain threshold, there is a significant downward trend in cognitive accuracy, suggesting that too high visual intensity will affect the cognitive accuracy. The results of this study provide new ideas for studying the potential mechanism of cognitive activity and the diagnosis and treatment of brain cognitive dysfunction.
Last Update: 2021-06-29