While neuropsychological deficits in both “hot” and “cool” executive functions (EFs) have been documented among individuals with attention-deficit/hyperactivity disorder (ADHD), these EF deficits are not universal across all individuals with this diagnosis. One potential moderator of executive dysfunction may be the presence of comorbid oppositional defiant disorder (ODD). This study examined the association between “hot” and “cool” EFs and comorbid ODD in children with ADHD. Thirty-three children with ADHD and comorbid ODD (ADHD+ODD), 67 with ADHD without ODD (ADHD-ODD), and 30 typically developing controls participated. Children were 7–12 years of age. “Cool” EFs were assessed with a spatial span task and a card sorting test. “Hot” EFs were assessed using a delay discounting task and a gambling task. ADHD-ODD and ADHD+ODD groups performed more poorly on “cool” EF tasks than controls, but did not differ from each other. Furthermore, the number of ADHD symptoms, but not ODD symptoms, was associated with “cool” EF scores. The three groups did not differ on “hot” EF tasks and the number of ADHD or ODD symptoms was unrelated to “hot” EF scores. In sum, children with ADHD presented with “cool” EF deficits which appear to be unrelated to ODD comorbidity. However, “hot” EF deficits were not present among children with ADHD, irrespective of comorbid ODD status. (JINS, 2015, 21, 584–595)

Linkages between neuropsychological functioning (i.e., response inhibition, processing speed, reaction time variability) and word reading have been documented among children with attention-deficit/hyperactivity disorder (ADHD) and children with Reading Disorders. However, associations between neuropsychological functioning and other aspects of reading (i.e., fluency, comprehension) have not been well-documented among children with comorbid ADHD and Reading Disorder. Children with ADHD and poor word reading (i.e., ≤25th percentile) completed a stop signal task (SST) and tests of word reading, reading fluency, and reading comprehension. Multivariate multiple regression was conducted predicting the reading skills from SST variables [i.e., mean reaction time (MRT), reaction time standard deviation (SDRT), and stop signal reaction time (SSRT)]. SDRT predicted word reading, reading fluency, and reading comprehension. MRT and SSRT were not associated with any reading skill. After including word reading in models predicting reading fluency and reading comprehension, the effects of SDRT were minimized. Reaction time variability (i.e., SDRT) reflects impairments in information processing and failure to maintain executive control. The pattern of results from this study suggest SDRT exerts its effects on reading fluency and reading comprehension through its effect on word reading (i.e., decoding) and that this relation may be related to observed deficits in higher-level elements of reading. (JINS, 2014, 20, 1–10)

Post-error slowing (i.e., slowing of a response on correct trials following an error) is thought to reflect adaptive behavior that may be impaired in Attention-Deficit/Hyperactivity Disorder (ADHD). The current study examined post-error slowing in children with ADHD and typically developing controls on two cognitive tasks. Fifty-one ADHD-Combined type, 53 ADHD-Inattentive type, and 47 controls completed a Choice Discrimination and Stop Signal Task with incentive and event rate manipulations. Linear mixed models were used to examine reaction times surrounding errors (trial-by-trial). Pre-error speeding and pre- to post-error slowing occurred on both tasks. Impaired post-error slowing was only present on the Choice Discrimination Task for the ADHD-Inattentive type. Post-error slowing is impaired in children with ADHD-Inattentive type, but not ADHD-Combined type, on a simple attention task. These findings highlight the importance of considering task demands and ADHD subtype when examining post-error slowing and also provide a novel approach to quantifying post-error slowing. (JINS, 2012, 18, 612–617)

A microanalysis of task events in a common go/no-go task was completed to examine how task events impact individual reaction times. Predictors of long reaction times were analyzed to better understand increased intra-individual variability (IIV) among children with ADHD compared with normal controls. Sixty-five children with ADHD and 65 normal controls matched on gender, ethnicity, and age completed a go/no-go task. Children across both groups were slower before and after omission errors than all other trials. They were also slower on the trial before successfully inhibiting their response to no-go trials. Children with ADHD exhibited a pronounced slowing on trials prior to omission errors and trials prior to successful inhibitions compared with the normal control group. Pre-error slowing in children with ADHD may represent the beginning stages of attentional disengagement that subsequently results in the absence of responding (i.e., errors of omission or successful inhibition). While these event-related increases in reaction time explain some of the increased IIV observed in children with ADHD, the removal of these trials did not remove the pronounced between-group differences in IIV, suggesting that additional unmeasured processes are contributing to IIV in children with ADHD. (JINS, 2010, 16, 138–147.)