Electrocortical indices of selective attention predict adolescent executive functioning

Development of auditory scene analysis: a mini-review

Most auditory environments contain multiple sound waves that are mixed before reaching the ears. In such situations, listeners must disentangle individual sounds from the mixture, performing the auditory scene analysis. Analyzing complex auditory scenes relies on listeners ability to segregate acoustic events into different streams, and to selectively attend to the stream of interest. Both segregation and selective attention are known to be challenging for adults with normal hearing, and seem to be even more difficult for children. Here, we review the recent literature on the development of auditory scene analysis, presenting behavioral and neurophysiological results. In short, cognitive and neural mechanisms supporting stream segregation are functional from birth but keep developing until adolescence. Similarly, from 6 months of age, infants can orient their attention toward a target in the presence of distractors. However, selective auditory attention in the presence of interfering streams only reaches maturity in late childhood at the earliest. Methodological limitations are discussed, and a new paradigm is proposed to clarify the relationship between auditory scene analysis and speech perception in noise throughout development.

What Has Been Learned from Using EEG Methods in Research of ADHD?

Electrophysiological recording methods, including electroencephalography (EEG) and magnetoencephalography (MEG), have an unparalleled capacity to provide insights into the timing and frequency (spectral) composition of rapidly changing neural activity associated with various cognitive processes. The current chapter provides an overview of EEG studies examining alterations in brain activity in ADHD, measured both at rest and during cognitive tasks. While EEG resting state studies of ADHD indicate no universal alterations in the disorder, event-related studies reveal consistent deficits in attentional and inhibitory control and consequently inform the proposed cognitive models of ADHD. Similar to other neuroimaging measures, EEG research indicates alterations in multiple neural circuits and cognitive functions. EEG methods - supported by the constant refinement of analytic strategies - have the potential to contribute to improved diagnostics and interventions for ADHD, underlining their clinical utility.

Modeling electrophysiological measures of decision-making and performance monitoring in neurotypical children engaging in a speeded flanker task

This study aims to use structural equation modeling (SEM) to investigate the role of error processing in behavioral adaptation in children by testing relationships between error-related and stimulus-related event-related potentials (ERPs) obtained from two sessions of a speeded Eriksen flanker task. First, path models of averaged ERP components and mean response times (N1 → P2 → N2 → P3 → RTs) while controlling for trait effects, age, and sex, on each was examined separately for correct and incorrect trials from each session. While the model demonstrated acceptable fit statistics, the four models yielded diverse results. Next, path models for correct and incorrect trials were tested using latent variables defined by factoring together respective measures of ERP component amplitudes from each session. Comparison of correct and incorrect models revealed significant differences in the relationships between the successive measures of neural processing after controlling for trait effects. Moreover, latent variable models controlling for both trait and session-specific state variables yielded excellent model fit while models without session-specific state variables did not. In the final model, the error-related neural activity (i.e., the ERN and Pe) from incorrect trials was found to significantly relate to the stream of neural processes contributing to trials with the correct behavior. Importantly, the relationship between RT and error detection in the final model signifies a brain-and-behavior feedback loop. These findings provided empirical evidence that supports the adaptive orienting theory of error processing by demonstrating how the neural signals of error processing influence behavioral adaptations that facilitate correct behavioral performance.

Test-Retest Reliability of Electroencephalographic Measures of Performance Monitoring in Children and Adults

This study examined the test-retest reliability of the error-related negativity (ERN) and error positivity (Pe) amplitudes using a Flanker task in 118 neurotypical children and 53 adults before and after latency jitter adjustments. The reliability of the ERN and Pe amplitudes was moderate for children and moderate to strong for adults. The latency variability adjustment did not improve the reliability of the ERN and Pe amplitudes for either group, suggesting that latency variability may be a trait-like measure. For comparison purposes, the reliability of the stimulus-locked ERPs was strong for correct trials, yet the reliability was weak for incorrect trials.

Does Anxiety Enhance or Hinder Attentional and Impulse Control in Youth With ADHD? An ERP Analysis

Objective: Youth with ADHD and comorbid anxiety (ADHD+ANX) experience increased social and academic impairment compared with youth with ADHD without anxiety (ADHD). Group differences in attentional and impulse control may underlie this increased impairment. Examination of group differences using behavioral measures of attentional and impulse control has yielded inconsistent findings. This study explored group differences using event-related potentials (ERPs), which provide neural information concerning early information processing. Method: ERPs (early frontal positivity [EFP], N2) were collected while youth aged 11 to 17 with ADHD (n = 31) and ADHD+ANX (n = 35) completed a visual and an auditory computer task. Results: Compared with the ADHD group, the ADHD+ANX group exhibited larger N2 amplitudes to no-go stimuli and larger EFP amplitudes to target auditory stimuli, with variable attention allocation to nontarget stimuli. Conclusion: The addition of anxiety to ADHD appears to alter early attentional processing, which may be an important aspect of this comorbidity.

Brain-based limitations in attention and secondary task engagement during high-fidelity driving simulation among young adults

Distracted driving remains a leading factor in fatal motor vehicle crashes, particularly in young drivers. Due to ongoing neuromaturation, attention capabilities are changing and improving throughout young adulthood. Here, we sought to bridge neuroscience with driving simulation by evaluating the effects of driving on attention processing through a selective auditory attention task. Participants (18-25 years old) engaged in an auditory attention task during LOAD (driving a high-fidelity simulator) and No-LOAD conditions (sitting in the parked simulator). For the auditory task, participants responded to a target auditory tone in a target ear. The event-related potential components, collected from frontal and posterior regions, P2 and P3, were used to evaluate attention processing across LOAD and No-LOAD conditions for attended and unattended stimuli. Data from 24 participants were evaluated in repeated measures ANOVAs, considering interactions between load and attention conditions for the P2 and P3 components of the cortical region. We observed a significant difference between response to attended and unattended stimuli for posterior P2 and P3 responses at the frontal and posterior midline sites. Comparing LOAD and No-LOAD conditions, there was a significant difference for P2 response at the posterior site and P3 response at the frontal site. A significant interaction between load and attended stimuli was found for P3 response at the posterior site. These data document differences in neural processing of auditory stimuli during high-fidelity simulated driving versus sitting parked in the simulator. Findings suggest the cognitive load of driving affects auditory attention.

An EEG Investigation of the Attention-Related Impact of Mindfulness Training in Youth With ADHD: Outcomes and Methodological Considerations

OBJECTIVE

The current study examined the impact of an activity-based mindfulness treatment on EEG indices of attention in youth with ADHD aged 11 to 17 years compared with a waitlist control group.

METHOD

Pre- and post-treatment, EEG was recorded as participants completed a single-point focus rest task and two active attention tasks. Theta power, beta power, and theta/beta ratio (TBR) were calculated during each task.

RESULTS

A significant group by time by task interaction was found that indicated significant improvement in attentional ability, indexed by decreased TBR, for the treatment group but not controls.

CONCLUSION

Findings support the benefit of mindfulness treatment for enhancing attentional control in youth with ADHD and extend the literature by providing evidence of these gains at a neural level. Findings also offer methodological support for the use of active attention tasks when examining mindfulness-related attentional gains in youth with ADHD. Directions for future research are discussed.

Novelty N2-P3a Complex and Theta Oscillations Reflect Improving Neural Coordination Within Frontal Brain Networks During Adolescence

Adolescents are easily distracted by novel items than adults. Maturation of the frontal cortex and its integration into widely distributed brain networks may result in diminishing distractibility with the transition into young adulthood. The aim of this study was to investigate maturational changes of brain activity during novelty processing. We hypothesized that during adolescence, timing and task-relevant modulation of frontal cortex network activity elicited by novelty processing improves, concurrently with increasing cognitive control abilities. A visual novelty oddball task was utilized in combination with EEG measurements to investigate brain maturation between 8–28 years of age (n = 84). Developmental changes of the frontal N2-P3a complex and concurrent theta oscillations (4–7 Hz) elicited by rare and unexpected novel stimuli were analyzed using regression models. N2 amplitude decreased, P3a amplitude increased, and latency of both components decreased with age. Pre-stimulus amplitude of theta oscillations decreased, while inter-trial consistency, task-related amplitude modulation and inter-site connectivity of frontal theta oscillations increased with age. Targets, intertwined in a stimulus train with regular non-targets and novels, were detected faster with increasing age. These results indicate that neural processing of novel stimuli became faster and the neural activation pattern more precise in timing and amplitude modulation. Better inter-site connectivity further implicates that frontal brain maturation leads to global neural reorganization and better integration of frontal brain activity within widely distributed brain networks. Faster target detection indicated that these maturational changes in neural activation during novelty processing may result in diminished distractibility and increased cognitive control to pursue the task.

The neuronal mechanisms underlying improvement of impulsivity in ADHD by theta/beta neurofeedback

Neurofeedback is increasingly recognized as an intervention to treat core symptoms of attention deficit hyperactivity disorder (ADHD). Despite the large number of studies having been carried out to evaluate its effectiveness, it is widely elusive what neuronal mechanisms related to the core symptoms of ADHD are modulated by neurofeedback. 19 children with ADHD undergoing 8 weeks of theta/beta neurofeedback and 17 waiting list controls performed a Go/Nogo task in a pre-post design. We used neurophysiological measures combining high-density EEG recording with source localization analyses using sLORETA. Compared to the waiting list ADHD control group, impulsive behaviour measured was reduced after neurofeedback treatment. The effects of neurofeedback were very specific for situations requiring inhibitory control over responses. The neurophysiological data shows that processes of perceptual gating, attentional selection and resource allocation processes were not affected by neurofeedback. Rather, neurofeedback effects seem to be based on the modulation of response inhibition processes in medial frontal cortices. The study shows that specific neuronal mechanisms underlying impulsivity are modulated by theta/beta neurofeedback in ADHD. The applied neurofeedback protocol could be particularly suitable to address inhibitory control. The study validates assumed functional neuroanatomical target regions of an established neurofeedback protocol on a neurophysiological level.

Specific cognitive-neurophysiological processes predict impulsivity in the childhood attention-deficit/hyperactivity disorder combined subtype

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent neuropsychiatric disorders in childhood. Besides inattention and hyperactivity, impulsivity is the third core symptom leading to diverse and serious problems. However, the neuronal mechanisms underlying impulsivity in ADHD are still not fully understood. This is all the more the case when patients with the ADHD combined subtype (ADHD-C) are considered who are characterized by both symptoms of inattention and hyperactivity/impulsivity.

METHOD

Combining high-density electroencephalography (EEG) recordings with source localization analyses, we examined what information processing stages are dysfunctional in ADHD-C (n = 20) compared with controls (n = 18).

RESULTS

Patients with ADHD-C made more impulsive errors in a Go/No-go task than healthy controls. Neurophysiologically, different subprocesses from perceptual gating to attentional selection, resource allocation and response selection processes are altered in this patient group. Perceptual gating, stimulus-driven attention selection and resource allocation processes were more pronounced in ADHD-C, are related to activation differences in parieto-occipital networks and suggest attentional filtering deficits. However, only response selection processes, associated with medial prefrontal networks, predicted impulsive errors in ADHD-C.

CONCLUSIONS

Although the clinical picture of ADHD-C is complex and a multitude of processing steps are altered, only a subset of processes seems to directly modulate impulsive behaviour. The present findings improve the understanding of mechanisms underlying impulsivity in patients with ADHD-C and might help to refine treatment algorithms focusing on impulsivity.

Auditory attention in childhood and adolescence: An event-related potential study of spatial selective attention to one of two simultaneous stories

Auditory selective attention is a critical skill for goal-directed behavior, especially where noisy distractions may impede focusing attention. To better understand the developmental trajectory of auditory spatial selective attention in an acoustically complex environment, in the current study we measured auditory event-related potentials (ERPs) across five age groups: 3-5 years; 10 years; 13 years; 16 years; and young adults. Using a naturalistic dichotic listening paradigm, we characterized the ERP morphology for nonlinguistic and linguistic auditory probes embedded in attended and unattended stories. We documented robust maturational changes in auditory evoked potentials that were specific to the types of probes. Furthermore, we found a remarkable interplay between age and attention-modulation of auditory evoked potentials in terms of morphology and latency from the early years of childhood through young adulthood. The results are consistent with the view that attention can operate across age groups by modulating the amplitude of maturing auditory early-latency evoked potentials or by invoking later endogenous attention processes. Development of these processes is not uniform for probes with different acoustic properties within our acoustically dense speech-based dichotic listening task. In light of the developmental differences we demonstrate, researchers conducting future attention studies of children and adolescents should be wary of combining analyses across diverse ages.

State, trait anxiety and selective attention differences in Attention Deficit Hyperactivity Disorder (ADHD) subtypes

One of the disorders that most affects school performance is Attention Deficit Hyperactivity Disorder (ADHD). The criteria established by DSM distinguish three subtypes: inattentive, hyperactive-impulsive and combined. However, the expression of this disorder can be altered by its association with other disorders such as anxiety. The main goals of this study were to determine whether different patterns of attention (selective and concentration) and anxiety (state and trait anxiety) emerge from ADHD subtypes, and analyze how anxiety predicts the performance of students with ADHD in a selective attention task. The sample was made up of 220 children (6-12 years) divided into four groups: control group (n = 56), inattentive subtype (n = 54), hyperactive-impulsive subtype (n = 53), and combined subtype (n = 57). The results indicated that the groups differed significantly in the attention variables, and in state and trait anxiety. Multiple group comparisons revealed that the combined subtype exhibited higher trait anxiety, whereas the inattentive subtype showed more state anxiety. Additionally, trait anxiety predicted the students’ performance in the concentration variable of the attention task. These results suggest a novel path of significant interest concerning objective and reliable diagnostic assessment of ADHD.