Effect of excessive Internet use on the time–frequency characteristic of EEG

We examined the effect of excessive Internet use on the time–frequency characteristic of the electroencephalogram by wavelet transformed and non-negative matrix factorization (NMF). The event-related potentials (ERP) of normal subjects and excessive Internet users were acquired using the oddball paradigm experiment. We applied the wavelet transformed and event-related spectral perturbation to ERP in order to extract the time–frequency values. The F-test statistics of time–frequency values were then decomposed into two components by NMF. Excessive Internet use resulted in a significant decrease in the P300 amplitudes (P < 0.05) and a significant increase in the P300 latency (P < 0.05) in all electrodes. The major effect of excessive Internet use on gamma oscillation occurred at ∼300 ms after stimuli at 40–50 Hz on the parietal central region. Thus, these data suggest that excessive Internet use affects information coding and integration in the brain.