Brain Mechanism and Intervention of Executive-control Dysfunction Among Substance Dependents

The adhesive electrodes were placed at F3 and F4 positions of the 64-bit EEG caps of the 10-20 system, corresponding to bilateral prefrontal lobes respectively. Before the intervention, the individual alpha frequency (IAF) of the subjects was measured according to the average peak value of α waves at dorsolateral prefrontal cortex in the closed state. Then an alternating current at θ frequency (θ = IAF - 5Hz) was applied to each subject based on its IAF value. The amplitude of stimulation was increased with a step of 20μA starting from 0. When the subjects had a slight prickling sensation or optical illusion, the stimulation current was decreased with a step of 20μA until the sensation disappeared. The current value at this time was used as the stimulation current of the subjects.

The adhesive electrodes were placed at F3 and F4 positions of the 64-bit EEG caps of the 10-20 system, corresponding to bilateral prefrontal lobes respectively. The actual stimulation waveform was just implemented in the first 60 s (or more longer) and then faded out.