Affiliations: Indiana University South Bend, IN, USA | University of South Carolina, Columbia, SC, USA
Note: [] Corresponding author: Dennis Rodriguez, Department of
Psychology, Indiana University South Bend, 1700 Mishawaka Avenue, South Bend,
IN 46634, USA. Tel.: +1 574 520 4396; Fax: +1 574 520 4538; E-mail:
[email protected]
Abstract: Previous research investigating attention and impulse control in
individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) has largely
ignored the symptomatic differences among the three subtypes of ADHD:
ADHD-Inattentive Type, ADHD-Hyperactive/Impulsive Type, and ADHD-Combined Type.
The present study examined attention and impulse control by focusing on these
subtypes. Based on their self-reported symptoms of ADHD, participants belonged
to one of four groups: ADHD-Inattentive, ADHD-Hyperactive/Impulsive,
ADHD-Combined, and control. Cortical activity was recorded from participants
during performance of a Go/NoGo task. The event-related potentials (ERP)
measured at frontal and posterior sites discriminated between the control group
and participants with symptoms of ADHD. The control group consistently
exhibited a higher P3 amplitude than all the ADHD groups. The main difference
occurred at the frontal site, indicating that individuals with ADHD symptoms
have deficits in the anterior attentional system, which mediates signal
detection. Behavioral measures of signal sensitivity revealed that the
ADHD-Inattentive and the ADHD-Hyperactive/Impulsive groups had more difficulty
with the attention-demanding Go/NoGo respond-to-target task, while behavioral
measures of response bias indicated that the ADHD-Hyperactive/Impulsive and the
ADHD-Combined groups responded more liberally in the inhibition-demanding
Go/NoGo suppress-to-target task.
