Differential Oscillatory Electroencephalogram Between Attention-Deficit/Hyperactivity Disorder Subtypes and Typically Developing Adolescents

Abstract

Background A neurobiological-based classification of Attention Deficit Hyperactivity Disorder (ADHD) subtypes has thus far remained elusive. The aim of this study was to use oscillatory changes in the electroencephalogram (EEG) related to informative cue processing, motor preparation, and top-down control to investigate neurophysiological differences between typically developing (TD) adolescents, and those diagnosed with predominantly inattentive (IA), or combined (associated with symptoms of inattention, as well as impulsivity/hyperactivity; CB) subtypes of ADHD. Methods EEG was recorded from 57 rigorously screened adolescents (aged 12 to17 years; 23 TD, 17 IA and 17 CB), while they performed a cued flanker task. We examined the oscillatory changes in theta (3–5 Hz), alpha (8–12 Hz) and beta (22–25 Hz) EEG bands following cues that informed participants with which hand they would subsequently be required to respond. Results Relative to TD adolescents the IA group showed significantly less post-cue alpha suppression, suggesting diminished processing of the cue in the visual cortex, whereas the CB group showed significantly less beta suppression at the electrode contralateral to the cued response hand, suggesting poor motor planning. Finally, both ADHD subtypes showed weak functional connectivity between frontal theta and posterior alpha, suggesting common top-down control impairment. Conclusions We found both distinct and common task-related neurophysiological impairments in ADHD subtypes. Our results suggest that task-induced changes in EEG oscillations provide an objective measure, which in conjunction with other sources of information might help distinguish between ADHD subtypes and therefore aid in diagnoses and evaluation of treatment.

Attention and Temporal Expectations Modulate Power, Not Phase, of Ongoing Alpha Oscillations

“…To ensure our results in the current study were consistent with those of previous literature showing attention-modulated suppression of alpha power (Mazaheri, Fassbender, et al, 2014;Mazaheri, van Schouwenburg, et al, 2014;Haegens et al, 2012;Haegens, Handel, et al, 2011;Kerlin et al, 2011;Hanslmayr et al, 2007;Jokisch & Jensen, 2007;Medendorp et al, 2007;Rihs et al, 2007;Sauseng et al, 2005;Thut et al, 2003), here, we did a correction for multiple comparisons. Cue-induced power differences for the alpha peak frequency were examined for every time point between cue and target presentation using a nonparametric randomization test (as described in Maris & Oostenveld, 2007) using alpha power from every participant's peak frequency.…”

Closed-loop brain training: the science of neurofeedback

“…These outcomes highlight two potentially critical issues in neurofeedback treatment of ADHD, patient heterogeneity and neurofeedback protocol efficacy. In relation to the former, new evidence suggests that a mixture of abnormal EEG resting-state signatures characterizes ADHD 97, [115][116][117] . Taskrelated EEG anomalies in individuals with ADHD have also been noted in theta and alpha oscillations 115,118,119 during visual attention 115 and in attenuated SCPs during anticipatory attention 73 .…”

“…In relation to the former, new evidence suggests that a mixture of abnormal EEG resting-state signatures characterizes ADHD 97, [115][116][117] . Taskrelated EEG anomalies in individuals with ADHD have also been noted in theta and alpha oscillations 115,118,119 during visual attention 115 and in attenuated SCPs during anticipatory attention 73 . Indeed, neurofeedback treatment involving the increase in negative SCP amplitude was associated with improved clinical symptoms [120][121][122] .…”

“…By contrast, combined EEG-fMRI studies in healthy subjects have found positive correlations between the functional activity of the DMN and the amplitude of EEG theta-alpha rhythms (4-12 Hz) [131][132][133] . Hence, an excess of task-related theta-alpha rhythms 115,134 , which may be reflective of an abnormally upregulated DMN, might be one candidate mechanism responsible for attentional deficits in ADHD. Interestingly, a recent EEG-fMRI study showed that suppressed alpha-rhythm amplitudes after neurofeedback training predicted reduced mind-wandering and were associated with upregulation of task-positive networks and downregulation of the DMN 18 .…”

Cognitive Flexibility, Theory of Mind, and Hyperactivity/Inattention

“…There is empirical and clinical evidence which indicates that hyperactivity and inattention can represent separate dimensions with different outcomes [55,56]. This opens up a range of alternative scenarios such as the possibility that inattention problems could result in delayed ToM development.…”