Normalisation of frontal theta activity following methylphenidate treatment in adult attention-deficit/hyperactivity disorder

The system‐neurophysiological basis for how methylphenidate modulates perceptual–attentional conflicts during auditory processing

“…Conflicts can occur between perceptual and attentional processes at multiple levels, for example, between competing sensory sources and sensory feature-based attention or executive attention that is important for maintaining task contexts, stimulus-response rules or response selections. As MPH acts as a mixed dopamine/norepinephrine transporter blocker, thus increasing synaptic dopamine (norepinephrine) levels (Faraone, 2018;Skirrow et al, 2015;Volkow et al, 1999), the data suggest that increased dopamine/norepinephrine levels enhance the resolution of perceptual-attentional conflicts. Compared to placebo, as anticipated the administration of MPH enhanced task performance, specifically in the most demanding FL conflict trials.…”

“…The shift in latency also underlies the differences in the magnitude of drug effects in the FL conflict condition compared to all other experimental conditions, which are associated with source activation differences in the left inferior parietal lobe (BA40) and left superior parietal lobe (BA7). As MPH acts as a mixed dopamine/norepinephrine transporter blocker (Skirrow et al, 2015;Volkow et al, 1999), modulations of the dopaminergic system and the norepinephrine system may underlie these effects in parietal regions. The source localization findings can be interpreted as such that MPH accelerates cognitive-neurophysiological processes associated with BA40 as well as BA7 and therefore enhances the resolution of perceptual-attentional conflicts or the use of sensory information during response selection processes.…”

“…Compared to placebo, as anticipated the administration of MPH enhanced task performance, specifically in the most demanding FL conflict trials. As MPH acts as a mixed dopamine/norepinephrine transporter blocker, thus increasing synaptic dopamine (norepinephrine) levels (Faraone, 2018;Skirrow et al, 2015;Volkow et al, 1999), the data suggest that increased dopamine/norepinephrine levels enhance the resolution of perceptual-attentional conflicts. However, drug effects on conflict resolution were only evident in FL when the low intensity (less salient), but behaviorally relevant stimulus was presented to the LE.…”

“…On the basis of these findings it is consistent that BA40 and BA7 were found to be associated with differences in the magnitude of drug effects during the resolution of perceptual-attentional conflicts. As MPH acts as a mixed dopamine/norepinephrine transporter blocker (Skirrow et al, 2015;Volkow et al, 1999), modulations of the dopaminergic system and the norepinephrine system may underlie these effects in parietal regions.…”

“…Methylphenidate (MPH) is a well-suited compound for this goal, because it acts as a mixed dopamine/norepinephrine transporter blocker, thus increasing dopamine and norepinephrine levels (Faraone, 2018;Skirrow et al, 2015;Volkow et al, 1999). We employed an intensity-modulated, focused-attention dichotic listening paradigm (Passow et al, 2014;Westerhausen et al, 2009), in which perceptual saliency of stimuli and the attentional focus were manipulated independently to investigate the interaction between auditory perception and attention.…”