Article

Event-Related fMRI of Inhibitory Control in the Predominantly Inattentive and Combined Subtypes of ADHD

Department of Psychiatry, Mount Sinai School of Medicine, New York, New York 10029, USA.
Journal of neuroimaging: official journal of the American Society of Neuroimaging (Impact Factor: 1.73). 08/2009; 19(3):205-12. DOI: 10.1111/j.1552-6569.2008.00289.x
Source: PubMed

ABSTRACT

To examine the neurophysiological basis for the pronounced differences in hyperactivity and impulsiveness that distinguish the predominantly inattentive type of attention-deficit/hyperactivity disorder (ADHD-PI) from the combined type of the disorder (ADHD-C).
Event-related brain responses to a go/no-go test of inhibitory control were measured with functional magnetic resonance imaging (fMRI) in 11 children with ADHD-C and 9 children with ADHD-PI, aged 7 to 13 years, who were matched for age, sex, and intelligence.
There were no significant group differences in task performance. Children with ADHD-C and ADHD-PI activated overlapping regions of right inferior frontal gyrus, right superior temporal lobe, and left inferior parietal lobe during inhibitory control. However, the magnitude of the activation in the temporal and parietal regions, as well as in the bilateral middle frontal gyrus, was greater in children with ADHD-PI than those with ADHD-C. Conversely, children with ADHD-C activated bilateral medial occipital lobe to a greater extent than children with ADHD-PI.
The results provide preliminary evidence that phenotypic differences between the ADHD-C and ADHD-PI subtypes are associated with differential activation of regions that have previously been implicated in the pathophysiology of ADHD and are thought to mediate executive and attentional processes.

    • "A fast event-related design with a predictable intertrial interval was employed to maximally tax sustained attention and avoid beneficial effects of jitter on performance (Wodka et al., 2009; Ryan et al., 2010; Lee et al., 2012). Similar non-jittered designs have been used in previous studies of attention fluctuations (Smith et al., 2006; Suskauer et al., 2008; Chikazoe et al., 2009; Solanto et al., 2009; Christoff et al., 2009; Esterman et al., 2013, 2014). A univariate analysis comparing activity evoked by error vs. correct trials further supported the validity of this design (see Supplementary Material). "
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    ABSTRACT: Although fluctuations in sustained attention are ubiquitous, most psychological experiments treat them as noise, averaging performance over many trials. The current study uses multi-voxel pattern analysis (MVPA) to decode whether, on each trial of a cognitive task, participants are in an optimal or suboptimal attentional state. During fMRI, participants performed n-back tasks, composed of central face images overlaid on distractor scenes, with low, perceptual, and working memory load. Instructions were to respond to novel faces and withhold response to rare repeats. To index attentional state, reaction time variability was calculated at each correct response. Participants' 50% least variable trials were labeled optimal, or "in the zone," and their 50% most erratic trials were labeled suboptimal, or "out of the zone." Support vector machine classifiers trained on activity in the default mode network (DMN), dorsal attention network (DAN), and task-relevant fusiform face area (FFA) distinguished in-the-zone and out-of-the-zone trials in all tasks. Consistent with evidence that distractors are processed when central task load is low, parahippocampal place area (PPA) classifiers were only successful in the low load task. Classification in anatomical regions across the brain revealed widespread coding of attentional state. In contrast to these robust pattern analyses, univariate signal in DMN, DAN, FFA, and PPA did not distinguish states, suggesting a nuanced relationship to sustained attention. In sum, MVPA can be used to decode trial-by-trial attentional state throughout much of cortex, helping to characterize how attention network fluctuations correlate with performance variability. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Mar 2015 · NeuroImage
    • "A fast event-related design with a predictable intertrial interval was employed to maximally tax sustained attention and avoid beneficial effects of jitter on performance (Wodka et al., 2009; Ryan et al., 2010; Lee et al., 2012). Similar non-jittered designs have been used in previous studies of attention fluctuations (Smith et al., 2006; Suskauer et al., 2008; Chikazoe et al., 2009; Solanto et al., 2009; Christoff et al., 2009; Esterman et al., 2013, 2014). A univariate analysis comparing activity evoked by error vs. correct trials further supported the validity of this design (see Supplementary Material). "

    No preview · Article · Aug 2014 · Journal of Vision
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    • "Response inhibition as measured by go/no-go tasks has emerged as one of the principal paradigms for studying ADHD (Aron and Poldrack, 2005). Using this task, it has been clearly demonstrated that children (Beauregard and Levesque, 2006; Derefinko et al., 2008; Durston et al., 2003; Inoue et al., 2012; Ma et al., 2012; Monden et al., 2012; Siniatchkin et al., 2012; Smith et al., 2006; Solanto et al., 2009; Vaidya et al., 1998), adolescents (Schulz et al., 2004; Tamm et al., 2004) and adults (Dibbets et al., 2009; Karch et al., 2010; Mulligan et al., 2011; Sebastian et al., 2012; Vasic et al., in press) with ADHD have response inhibition deficits. An extensive review of functional neuroimaging in healthy adults indicates that widespread regions of the frontal cortex, especially the right inferior frontal gyrus (IFG), are associated with response inhibition (Aron and Poldrack, 2005). "
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    ABSTRACT: An objective biomarker is a compelling need for the early diagnosis of attention deficit hyperactivity disorder (ADHD), as well as for the monitoring of pharmacological treatment effectiveness. The advent of fNIRS, which is relatively robust to the body movements of ADHD children, raised the possibility of introducing functional neuroimaging diagnosis in younger ADHD children. Using fNIRS, we monitored the oxy-hemoglobin signal changes of 16 ADHD children (6 to 13 years old) performing a go/no-go task before and 1.5 h after MPH or placebo administration, in a randomized, double-blind, placebo-controlled, crossover design. 16 age-and gender-matched normal controls without MPH administration were also monitored. Relative to control sub-jects, unmedicated ADHD children exhibited reduced activation in the right inferior frontal gyrus (IFG) and middle frontal gyrus (MFG) during go/no-go tasks. The reduced right IFG/MFG activation was acutely nor-malized after MPH administration, but not after placebo administration. The MPH-induced right IFG/MFG activation was significantly larger than the placebo-induced activation. Post-scan exclusion rate was 0% among 16 right-handed ADHD children with IQ > 70. We revealed that the right IFG/MFG activation could serve as a neuro-functional biomarker for monitoring the acute effects of methylphenidate in ADHD children. fNIRS-based examinations were applicable to ADHD children as young as 6 years old, and thus would con-tribute to early clinical diagnosis and treatment of ADHD children.
    Full-text · Dataset · Sep 2013
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