An Examination of EEG Frequency Components Related to Speech Imagery and Its Identification

2019 ◽  
Vol 139 (5) ◽  
pp. 588-595
Author(s):  
Akihiko Tsukahara ◽  
Masayuki Yamada ◽  
Keita Tanaka ◽  
Yoshinori Uchikawa
Psychiatry ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 39-45
Author(s):  
E. V. Damyanovich ◽  
E. V. Iznak ◽  
I. V. Oleichik ◽  
A. F. Iznak

Background: the study of clinical and neurophysiological aspects of non-suicidal self-injurious behavior (NSSI), as one of the forms and risk factors for suicidal behavior in adolescents, including those suffering from mental disorders, is an urgent medical and social scientific task. Objective: To identify the features of EEG in depressive adolescent females with NSSI compared with EEG of age norm. Patients and methods: the study included 60 female patients aged 16–25 years with NSSI in the structure of endogenous depressive conditions, and 20 healthy subjects of the same gender and age. Clinical, psychopathological, psychometric, neurophysiological and statistical methods were used. Topographic EEG mapping revealed differences in the background EEG quantitative parameters of two studied groups. Results and discussion: spectral power values of alpha-2 (9–11 Hz) and alpha-1 (8–9 Hz) EEG frequency components in occipital-parietal and temporal leads, of theta-2 activity (6–8 Hz) in central-parietal leads, as well as of delta activity (2–4 Hz) in frontal and anterior temporal leads were higher in the left hemisphere, reflected increased activation of the right hemisphere. Generalized bilaterally synchronous alpha-theta bursts were registered regularly in EEG of NSSI patients, as well. Conclusions: the spatial distribution of EEG frequency components in depressive patients with NSSI indicates relatively decreased functional state of the cortex, especially of the left hemisphere and of its anterior regions, responsible for voluntary control of activity, with higher level of activation of temporal regions of the right hemisphere, associated with formation of negative emotions, and increased excitability of brain limbic-diencephalic structures, that may underlie poor controlled impulsive behavior.


Author(s):  
Olga Korzgyk ◽  
Alevtyna Morenko

A test group consisting of 113 right-hand healthy women from the ages of 19 to 21 was divided into two groups according to the average magnitude of their individual modal α- frequency – groups with high and low values of individual modal α- frequency. The ideal time of a simple sensorimotor reaction and choice-point behavior as well as speed capabilities of nervous processes during the tapping test, and measures of the coherence of EEG frequency components individually determined for each testee in quiescent intervals and while performing alternative movements by the right hand fingers were evaluated. Women with high modal α-frequency had better speed capabilities of nervous processes. Women with a high IαF had a less time of simple and complex reactions. The increase of coherence coefficients was seen throughout the EEG frequency spectrum in women performing alternate movements by fingers. Alternate movements of fingers performed by women with low α-frequency are provided by even higher frequency coherence of the EEG components in frontal, anterior temporal and central areas and by much lower frequency in the posterior temporal and parietal-occipital cortex areas compared to testees with high α-frequency.


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