Brain oscillations, inhibitory control mechanisms and rewarding bias in web addiction. Two opposite young subjects' clusters?

Internet Addiction (IA) is considered a subtype of impulse control disorder, and a behavior related to rewarding system deficits. However whether and how impulse control deficits are related to in rewarding mechanisms is actually unexplored. The present research aims to examine the neural correlates of deficits in inhibitory control and the rewarding mechanisms in IA in a sample of young people. Internet Addiction Inventory (IAT) was applied to a subclinical sample. Secondly, cortical oscillations (frequency bands) and personality trait (Behavioral Inhibition System, BIS; Behavioral Activation System, BAS) were considered to explain IA. Oscillatory brain activity (delta, theta, alpha, beta and gamma) and response times (RTs) were monitored during the performance of a Go/No Go task in response online gambling videos, videogames or neutral stimuli. BAS, BAS-R (BAS-Reward subscale), BIS and IAT predicted the low-frequency band variations, although in an opposite direction: reduced delta and theta and RTs values were found for higher BAS, BAS-R and IAT, in the case of NoGo for gambling and videogames stimuli; in contrast increased delta and theta and RTs values were observed for higher BIS. Two potential different young subjects' clusters were suggested: with low inhibitory impulse control and rewarding bias (higher BAS and IAT); and with impulse hyper-control (higher BIS).