Öz
DOI: 10.26650/electrica.2018.99730
According
to clinical symptoms, attention deficit and hyperactivity disorder (ADHD) is
categorized into three groups: the predominantly inattentive subtype (ADHD-I),
the predominantly hyperactive-impulsive subtype (ADHD-HI), and the combined
subtype (ADHD-C). Recent advances in neuroimaging have demonstrated new
approaches for assessing the ADHD subtypes with underlying pathophysiology.
This study aims to examine the hemodynamic response and reaction time (RT) in
healthy children and the ADHD subtypes as measured by functional near-infrared
spectroscopy (fNIRS) during an auditory oddball attention task. The sample was
made up of 40 children divided into four groups: control group (n=14), ADHD-I
group (n=9), ADHD-HI group (n=6), and ADHD-C group (n=11). The target responses
were identified and were grand-averaged for each participant. Right prefrontal
cortex hemodynamic responses and groups performances on RT were compared
between subtypes and between controls and subtypes. Functional near-infrared
spectroscopy indicated that while control subjects exhibited higher activation
than all ADHD subtypes, the ADHD subtypes did not differ from one another.
Relative to control subjects, a longer RT was observed in all ADHD subtypes.
The ADHD-I group showed significantly longer RTs compared to the ADHD-HI and
ADHD-C groups. This study can bring a new perspective to the continuing
controversy about ADHD subtypes, and the findings may help in the evaluation of
fNIRS, RT, and RT variability studies in ADHD.