Pharmaco-MEG evidence for attention related hyper-connectivity between auditory and prefrontal cortices in ADHD.
The ability to attend to particular stimuli while ignoring others is crucial in goal-directed activities and has been linked with prefrontal cortical regions, including the dorsolateral prefrontal cortex (DLPFC). Both hyper- and hypo-activation in the DLPFC has been reported in patients with attention-deficit/hyperactivity disorder (ADHD) during many different cognitive tasks, but the network-level effects of such aberrant activity remain largely unknown. Using magnetoencephalography (MEG), we examined functional connectivity between regions of the DLPFC and the modality-specific auditory cortices during an auditory attention task in medicated and un-medicated adults with ADHD, and those without ADHD. Participants completed an attention task in two separate sessions (medicated/un-medicated), and each session consisted of two blocks (attend and no-attend). All MEG data were coregistered to structural MRI, corrected for head motion, and projected into source space. Subsequently, we computed the phase coherence (i.e., functional connectivity) between DLPFC regions and the auditory cortices. We found that un-medicated adults with ADHD exhibited greater phase coherence in the beta (14-30Hz) and gamma frequency (30-56Hz) range in attend and no-attend conditions compared to controls. Stimulant medication attenuated these differences, but did not fully eliminate them. These results suggest that aberrant bottom-up processing may engulf executive resources in ADHD.
Department of Psychology, University of Nebraska, Omaha, NE, USA; Center for Magnetoencephalography (MEG), University of Nebraska Medical Center, Omaha, NE, USA.
Elizabeth
E
Heinrichs-Graham
Department of Psychiatry, Bryan Health Medical Center, Lincoln, NE, USA; Department of Psychiatry, University of Nebraska Medical Center, Omaha, NE, USA.
John D
JD
Franzen
Center for Magnetoencephalography (MEG), University of Nebraska Medical Center, Omaha, NE, USA.
Nichole L
NL
Knott
Department of Radiology, University of Nebraska Medical Center, Omaha, NE, USA.
Matthew L
ML
White
Department of Psychiatry, University of Nebraska Medical Center, Omaha, NE, USA; Mental Health Unit, Lincoln Correctional Center, Nebraska Department of Correctional Services, Lincoln, NE, USA.
Martin W
MW
Wetzel
Center for Magnetoencephalography (MEG), University of Nebraska Medical Center, Omaha, NE, USA; Department of Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA; Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA. Electronic address: Tony.W.Wilson@gmail.com.
Tony W
TW
Wilson
D000328:Adult; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D001303:Auditory Cortex / Q000503:physiopathology*; D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000503:physiopathology*
D000697:Central Nervous System Stimulants
Beta; Cortex; DLPFC; Gamma; Magnetoencephalography; Stimulants