Considering Motor Excitability During Action Preparation in Gambling Disorder: A Transcranial Magnetic Stimulation Study

Abstract

A lack of inhibitory control appears to contribute to the development and maintenance of addictive disorders. Among the mechanisms thought to assist inhibitory control, an increasing focus has been drawn on the so-called preparatory suppression, which refers to the drastic suppression observed in the motor system during action preparation. Interestingly, deficient preparatory suppression has been reported in alcohol use disorders. However, it is currently unknown whether this deficit also concerns behavioral, substance-free, addictions, and thus whether it might represent a vulnerability factor common to both substance and behavioral addictive disorders. To address this question, neural measures of preparatory suppression were obtained in gambling disorder patients (GDPs) and matched healthy control subjects. To do so, single-pulse transcranial magnetic stimulation was applied over the left and the right motor cortex to elicit motor-evoked potentials (MEPs) in both hands when participants were performing a choice reaction time task. In addition, choice and rapid response impulsivity were evaluated in all participants, using self-report measures and neuropsychological tasks. Consistent with a large body of literature, the MEP data revealed that the activity of the motor system was drastically reduced during action preparation in healthy subjects. Surprisingly, though, a similar MEP suppression was observed in GDPs, indicating that those subjects do not globally suffer from a deficit in preparatory suppression. By contrast, choice impulsivity was higher in GDPs than healthy subjects, and a higher rapid response impulsivity was found in the more severe forms of GD. Altogether, those results demonstrated that although some aspects of inhibitory control are impaired in GDPs, these alterations do not seem to concern preparatory suppression. Yet, the profile of individuals suffering of a GD is very heterogeneous, with only part of them presenting an impulsive disposition, such as in patients with alcohol use disorders. Hence, a lack of preparatory suppression may be only shared by this sub-type of addicts, an interesting issue for future investigation.

Augmented tendency to act and altered impulse control in alcohol use disorders

“…First, chronic alcohol consumption has important neurotoxic effects, with the most pronounced damage reported in regions underpinning impulse control, such as the frontal lobes and the basal ganglia ( Chanraud et al, 2007 , Fritz et al, 2019 ), and the degree of brain atrophy correlates with the amount of alcohol previously consumed ( Rolland et al, 2020 ). Moreover, we have shown that a weaker MEP suppression during action preparation was associated with a lower cortical thickness in medial frontal regions ( Quoilin et al, 2021 ), while patients suffering from a behavioral, substance-free, addiction, had a normal pattern of MEP suppression ( Quoilin et al, 2020 ). Finally, here, HDs reported a considerably lower alcohol consumption than SAUDs, which could explain the lack of visible impairment in the strength of inhibitory influences.…”

“…Participants performed an instructed-delay choice RT task, which was implemented with Matlab 7.5 (Mathworks, Natick, Massachusetts, USA) using the Psychophysics Toolbox extensions ( Brainard, 1997 , Pelli, 1997 ). It consisted in a computer-generated “rolling ball” game previously used in other studies, requiring participants to virtually shoot a ball displayed on the computer screen by abducting their left or right index finger ( Grandjean et al, 2019 , Quoilin et al, 2020 , Vassiliadis et al, 2018 ).…”

“…EMG data were collected for 3200 ms on each trial, starting always 200 ms before the TMS pulse. Trials with any background EMG activity (root mean square computed in the 200 ms windows preceding the TMS pulse) exceeding 2.5 SD above the mean were removed; this was made for each muscle to prevent contamination of the MEP measurements by significant fluctuations in background EMG ( Grandjean et al, 2019 , Quoilin et al, 2020 ). Trials in which subjects made an error were also discarded.…”

Corticospinal suppression underlying intact movement preparation fades in late Parkinson’s disease

“…After having undergone all pre-cited evaluations and questionnaires, for the main part of the experiment, participants were installed in a quiet and dimly-lit room, in front of a computer screen positioned about 60 cm in front of them, with both forearms resting on a table in a semiflexed position. Participants performed an instructed-delay choice RT task involving left or right index finger responses, which was implemented by means of Matlab 7.5 (The Mathworks, Natick, MA, USA) using the Psychophysics Toolbox extensions [67,68] were placed palms down on a homemade response device (one for each hand) allowing to detect any horizontal movement of the index fingers [29,30,69]. Each response device was composed of one horizontal outer and one vertical inner metal plate (Fig.…”

The motive for the action of online gambling as an additional livelihood during social restrictions due to the Covid-19 pandemic

“…Many teenagers or adults play gambling because they are experimenting or curious about the game because of the many advertisements circulating on the internet and various social media platforms. These advertisements will persuade or compel them to play online gambling with the lure to get money instantly and quickly just by playing games only (Quoilin et al 2020). The persuasion of the advertisement will affect the public if the public cannot digest and be careful so that it affects the people's actions to carry out the gambling game.…”