| Transcranial alternating current stimulation(t ACS)is a non-invasive method of brain stimulation that modulates oscillatory neural activity in the cortical region beneath the electrodes.Analyzing the beneficial effects of electrical stimulation through behavioral data collected from electrical stimulation of the human brain is currently a research hotspot in this direction.Starting from transcranial alternating current stimulation,combined with different behavioral paradigms and data analysis,this paper explores the behavioral changes and EEG changes of healthy adults after electrical stimulation.(1)The results of previous studies have shown that t ACS on the primary motor cortex(M1)can enhance motor learning and memory during motor learning tasks.However,there are few studies on the impact of motor learning and consolidation.The article investigated the effect of t ACS applied to M1 on motor learning skills and consolidation.A group of healthy young adults performed a serial reaction time task(SRTT)with the right hand before and after t ACS.Each subject received sham,β-band(20 Hz-t ACS)and γ-band(70 Hz-t ACS)stimulation.The effects of stimulation on the learning and consolidation of general motor skills(GMS)and sequence-specific skills(SS)were investigated.The experimental results showed that both β-t ACS and γ-t ACS produced effective improvement in the consolidation of GMS and SS.And in γ-t ACS,the consolidation of both skills improved significantly compared with sham stimulation..(2)Working memory(WM)is crucial for intelligent cognitive function,and synchronization in the frontal-parietal network has been considered as a potential neural mechanism.To provide causal evidence for this hypothesis,the research applied θ-t ACS to the fronto-parietal region in the n-back task.Eighteen subjects(nine women)received frontal stimulation,parietal stimulation,and sham stimulation in random order.While being stimulated,subjects completed a working memory span task and an n-back task with varying executive demands(two levels: low and high,grouped according to baseline span values).The experiments showed that left DLPFC stimulation had a beneficial effect on WM performance.By analyzing the experimental data,it was found that compared with sham stimulation,t ACS stimulation of the left DLPFC improved the reaction time and accuracy under the same stimulation.Several experiments have shown that a single session of anodal electrical stimulation on the left parietal lobe contributes to the improvement of WM performance.However,this was not a universal finding,nor was there a significant difference in behavioral task reaction time between the parietal group and the control group in this study.(3)On the basis of the previous section,the EEG signals during resting state and performing behavioral tasks were collected,analysis of power peaks in frequency bands δ、θ、α、 β and γ.The experimental results show that the power spectral density of the δ、θ and α bands decreases statistically significantly from pre-task to post-task,while the other two bands increase.This indicated a significant change in EEG amplitude during the task compared to the pre-stimulus EEG data.After that,some electrodes in the region of interest were selected for further analysis,and the results showed that there was an interaction effect between the frequency band and the two task states in each frequency band.The amplitudes vary from site to site.The experimental results also showed that individuals with lower resting theta power exhibited a greater percentage increase in evoked power during task performance than subjects with higher resting theta power. |
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