Neural circuitry underlying sustained attention in healthy adolescents and in ADHD symptomatology

Abstract

Moment-to-moment reaction time variability on tasks of attention, often quantified by intra-individual response variability (IRV), provides a good indication of the degree to which an individual is vulnerable to lapses in sustained attention. Increased IRV is a hallmark of several disorders of attention, including Attention-Deficit/Hyperactivity Disorder (ADHD). Here, task-based fMRI was used to provide the first examination of how average brain activation and functional connectivity patterns in adolescents are related to individual differences in sustained attention as measured by IRV. We computed IRV in a large sample of adolescents (n = 758) across 'Go' trials of a Stop Signal Task (SST). A data-driven, multi-step analysis approach was used to identify networks associated with low IRV (i.e., good sustained attention) and high IRV (i.e., poorer sustained attention). Low IRV was associated with greater functional segregation (i.e., stronger negative connectivity) amongst an array of brain networks, particularly between cerebellum and motor, cerebellum and prefrontal, and occipital and motor networks. In contrast, high IRV was associated with stronger positive connectivity within the motor network bilaterally and between motor and parietal, prefrontal, and limbic networks. Consistent with these observations, a separate sample of adolescents exhibiting elevated ADHD symptoms had increased fMRI activation and stronger positive connectivity within the same motor network denoting poorer sustained attention, compared to a matched asymptomatic control sample. With respect to the functional connectivity signature of low IRV, there were no statistically significant differences in networks denoting good sustained attention between the ADHD symptom group and asymptomatic control group. We propose that sustained attentional processes are facilitated by an array of neural networks working together, and provide an empirical account of how the functional role of the cerebellum extends to cognition in adolescents. This work highlights the involvement of motor cortex in the integrity of sustained attention, and suggests that atypically strong connectivity within motor networks characterizes poor attentional capacity in both typically developing and ADHD symptomatic adolescents.

A Combination of Impulsivity Subdomains Predict Alcohol Intoxication Frequency

“…We considered IRV an impulsivity‐related measure, as it was embedded in an impulsivity‐specific task (for a discussion, see Sharma et al., ). Furthermore, IRV has been implicated in motor and prefrontal brain regions that are typically associated with cognitive control (O'Halloran et al., ). Sharma and colleagues () who, in a hypothetical demonstration of results that might be obtained if a battery of impulsivity measures was administered jointly along with alcohol use, indicated that tasks assaying inattention alone would not significantly predict problematic alcohol use, but would when combined with other impulsive measures.…”

“…A measure of cognitive impulsivity examining sustained attention, the intraindividual coefficient of variation (IRV; standard deviation of reaction times divided by mean reaction time), was calculated from the go trials of the SST for each participant (O'Halloran et al., ).…”

Inhibitory‐control event‐related potentials correlate with individual differences in alcohol use

“…Full SST task details are contained in the Supplementary Information (task‐based measures) file. A measure of cognitive impulsivity quantifying sustained attention, the intraindividual coefficient of variation (IRV; standard deviation of reaction times divided by mean reaction time), was calculated from the correct Go trials of the SST for each participant [see previous study for details].…”

“…Although different aspects of alcohol use (eg, intoxication and consumption frequency) have been previously linked to different aspects of impulsivity, it is not clear how measures of hazardous consumption are related to various impulsivity domains. Previous studies examining the relationship between impulsivity‐related ERPs and alcohol focused on number of drinks consumed (see previous studies).…”

Functional connectivity predicts changes in attention over minutes, days, and months

“…In contrast to the discussions on dynamics, there is growing consensus that models based on individuals' unique patterns of static functional brain connectivity can predict individual differences in abilities including fluid intelligence Greene et al, 2018), working memory (Avery et al;Galeano Weber et al, 2017;Yamashita et al, 2018), and attention (Kessler et al, 2016;O'Halloran et al, 2018;Poole et al, 2016;Rosenberg et al, 2017;. The most extensively validated connectome-based predictive model (CPM), the sustained attention CPM (Rosenberg et al, 2016a), has generalized across six independent data sets and participant populations to predict individuals' overall sustained attention function from data collected during rest and five different tasks (Fountain-Zaragoza et al, 2019;Jangraw et al, 2018;Rosenberg et al, 2016aRosenberg et al, , 2016bRosenberg et al, , 2018a.…”