Reverse hierarchies and sensory learning

Revealing the relationships between perceptual representations in the brain and mechanisms of adult perceptual learning is of great importance, potentially leading to significantly improved training techniques both for improving skills in the general population and for ameliorating deficits in special populations. In this review, we summarize the essentials of reverse hierarchy theory for perceptual learning in the visual and auditory modalities and describe the theory's implications for designing improved training procedures, for a variety of goals and populations.

A dichoptic custom-made action video game as a treatment for adult amblyopia

Previous studies have employed different experimental approaches to enhance visual function in adults with amblyopia including perceptual learning, videogame play, and dichoptic training. Here, we evaluated the efficacy of a novel dichoptic action videogame combining all three approaches. This experimental intervention was compared to a conventional, yet unstudied method of supervised occlusion while watching movies. Adults with unilateral amblyopia were assigned to either play the dichoptic action game (n=23; 'game' group), or to watch movies monocularly while the fellow eye was patched (n=15; 'movies' group) for a total of 40hours. Following training, visual acuity (VA) improved on average by ≈0.14logMAR (≈28%) in the game group, with improvements noted in both anisometropic and strabismic patients. This improvement is similar to that obtained following perceptual learning, video game play or dichoptic training. Surprisingly, patients with anisometropic amblyopia in the movies group showed similar improvement, revealing a greater impact of supervised occlusion in adults than typically thought. Stereoacuity, reading speed, and contrast sensitivity improved more for game group participants compared with movies group participants. Most improvements were largely retained following a 2-month no-contact period. This novel video game, which combines action gaming, perceptual learning and dichoptic presentation, results in VA improvements equivalent to those previously documented with each of these techniques alone. Our game intervention led to greater improvement than control training in a variety of visual functions, thus suggesting that this approach has promise for the treatment of adult amblyopia.

Brain plasticity-based therapeutics

The primary objective of this review article is to summarize how the neuroscience of brain plasticity, exploiting new findings in fundamental, integrative and cognitive neuroscience, is changing the therapeutic landscape for professional communities addressing brain-based disorders and disease. After considering the neurological bases of training-driven neuroplasticity, we shall describe how this neuroscience-guided perspective distinguishes this new approach from (a) the more-behavioral, traditional clinical strategies of professional therapy practitioners, and (b) an even more widely applied pharmaceutical treatment model for neurological and psychiatric treatment domains. With that background, we shall argue that neuroplasticity-based treatments will be an important part of future best-treatment practices in neurological and psychiatric medicine.

Low-level information and high-level perception: the case of speech in noise

Auditory information is processed in a fine-to-crude hierarchical scheme, from low-level acoustic information to high-level abstract representations, such as phonological labels. We now ask whether fine acoustic information, which is not retained at high levels, can still be used to extract speech from noise. Previous theories suggested either full availability of low-level information or availability that is limited by task difficulty. We propose a third alternative, based on the Reverse Hierarchy Theory (RHT), originally derived to describe the relations between the processing hierarchy and visual perception. RHT asserts that only the higher levels of the hierarchy are immediately available for perception. Direct access to low-level information requires specific conditions, and can be achieved only at the cost of concurrent comprehension. We tested the predictions of these three views in a series of experiments in which we measured the benefits from utilizing low-level binaural information for speech perception, and compared it to that predicted from a model of the early auditory system. Only auditory RHT could account for the full pattern of the results, suggesting that similar defaults and tradeoffs underlie the relations between hierarchical processing and perception in the visual and auditory modalities.

A novel, online social cognitive training program for young adults with schizophrenia: A pilot study

BACKGROUND

Pervasive social cognition deficits are evident early in the course of schizophrenia and are directly linked to functional outcome, making them an important target for intervention. Here, we tested the feasibility of use, and initiated the evaluation of efficacy, of a novel, neuroplasticity-based online training program (SocialVille) in young adults with schizophrenia.

METHODS

Schizophrenia patients (n=17) completed 24 hours of online SocialVille game play either from home or at a clinic, over a 6-10 week period. We examined training feasibility, gains on the SocialVille exercises relative to matched healthy controls (n=17), and changes on measures of social cognition, social functioning, global functioning and motivation.

RESULTS

Subjects adhered to training requirements, and rated SocialVille in the medium to high range in satisfaction, enjoyment, and ease of use. Subjects demonstrated significant, large improvements on the speeded SocialVille tasks, and small to moderate improvements on the working memory tasks. Post-training performance on the SocialVille tasks were similar to initial performance of the healthy controls. Subjects also showed improvements on standard measures of social cognition, social functioning, and motivation. No improvements were recorded for emotion recognition indices on the MSCEIT, or on quality of life scales.

CONCLUSION

This study provides an initial proof of concept for online social cognition training in schizophrenia. This form of training demonstrated feasibility and resulted in within-subject gains in social functioning and motivation. This pilot study represents a first step towards validating this training approach; randomized controlled trials, now underway, are designed to confirm and extend these findings.

Mechanisms of recovery of visual function in adult amblyopia through a tailored action video game

Amblyopia is a deficit in vision that arises from abnormal visual experience early in life. It was long thought to develop into a permanent deficit, unless properly treated before the end of the sensitive period for visual recovery. However, a number of studies now suggest that adults with long-standing amblyopia may at least partially recover visual acuity and stereopsis following perceptual training. Eliminating or reducing interocular suppression has been hypothesized to be at the root of these changes. Here we show that playing a novel dichoptic video game indeed results in reduced suppression, improved visual acuity and, in some cases, improved stereopsis. Our relatively large cohort of adults with amblyopia, allowed us, for the first time, to assess the link between visual function recovery and reduction in suppression. Surprisingly, no significant correlation was found between decreased suppression and improved visual function. This finding challenges the prevailing view and suggests that while dichoptic training improves visual acuity and stereopsis in adult amblyopia, reduced suppression is unlikely to be at the root of visual recovery. These results are discussed in the context of their implication on recovery of amblyopia in adults.

Immediate Mood Scaler: Tracking Symptoms of Depression and Anxiety Using a Novel Mobile Mood Scale

BACKGROUND

Mood disorders are dynamic disorders characterized by multimodal symptoms. Clinical assessment of symptoms is currently limited to relatively sparse, routine clinic visits, requiring retrospective recollection of symptoms present in the weeks preceding the visit. Novel advances in mobile tools now support ecological momentary assessment of mood, conducted frequently using mobile devices, outside the clinical setting. Such mood assessment may help circumvent problems associated with infrequent reporting and better characterize the dynamic presentation of mood symptoms, informing the delivery of novel treatment options.

OBJECTIVES

The aim of our study was to validate the Immediate Mood Scaler (IMS), a newly developed, iPad-deliverable 22-item self-report tool designed to capture current mood states.

METHODS

A total of 110 individuals completed standardized questionnaires (Patient Health Questionnaire, 9-item [PHQ-9]; generalized anxiety disorder, 7-Item [GAD-7]; and rumination scale) and IMS at baseline. Of the total, 56 completed at least one additional session of IMS, and 17 completed one additional administration of PHQ-9 and GAD-7. We conducted exploratory Principal Axis Factor Analysis to assess dimensionality of IMS, and computed zero-order correlations to investigate associations between IMS and standardized scales. Linear Mixed Model (LMM) was used to assess IMS stability across time and to test predictability of PHQ-9 and GAD-7 score by IMS.

RESULTS

Strong correlations were found between standard mood scales and the IMS at baseline (r=.57-.59, P<.001). A factor analysis revealed a 12-item IMS ("IMS-12") with two factors: a "depression" factor and an "anxiety" factor. IMS-12 depression subscale was more strongly correlated with PHQ-9 than with GAD-7 (z=1.88, P=.03), but the reverse pattern was not found for IMS-12 anxiety subscale. IMS-12 showed less stability over time compared with PHQ-9 and GAD-7 (.65 vs .91), potentially reflecting more sensitivity to mood dynamics. In addition, IMS-12 ratings indicated that individuals with mild to moderate depression had greater mood fluctuations compared with individuals with severe depression (.42 vs .79; P=.04). Finally, IMS-12 significantly contributed to the prediction of subsequent PHQ-9 (beta=1.03, P=.02) and GAD-7 scores (beta =.93, P=.01).

CONCLUSIONS

Collectively, these data suggest that the 12-item IMS (IMS-12) is a valid tool to assess momentary mood symptoms related to anxiety and depression. Although IMS-12 shows good correlation with standardized scales, it further captures mood fluctuations better and significantly adds to the prediction of the scales. Results are discussed in the context of providing continuous symptom quantification that may inform novel treatment options and support personalized treatment plans.

Online Social Cognition Training in Schizophrenia: A Double-Blind, Randomized, Controlled Multi-Site Clinical Trial

Social cognition (SC), the mental operations underlying social functioning, are impaired in schizophrenia. Their direct link to functional outcome and illness status have made them an important therapeutic target. However, no effective treatment for these deficits is currently applied as a standard of care. To address this need, we have developed SocialVille-an online, plasticity-based training program that targets SC deficits in schizophrenia. Here we report the outcomes of a double-blind, controlled, randomized, multi-site clinical trial of SocialVille. Outpatients with schizophrenia were randomized to complete 40 sessions of either SocialVille (N = 55 completers) or active control (computer games; N = 53 completers) from home. The a priori co-primary outcome measures were a social cognitive composite and a functional capacity outcome (UCSD Performance-based Skills Assessment [UPSA-2]). Secondary outcomes included a virtual functional capacity measure (VRFCAT), social functioning, quality of life, and motivation. Linear mixed models revealed a group × time interaction favoring the treatment group for the social cognitive composite (b = 2.81; P < .001) but not for the UPSA-2 measure. Analysis of secondary outcome measures showed significant group × time effects favoring the treatment group on SC and social functioning, on the virtual functional capacity measure and a motivation subscale, although these latter findings were nonsignificant with FDR correction. These results provide support for the efficacy of a remote, plasticity-based social cognitive training program in improving SC and social functioning in schizophrenia. Such treatments may serve as a cost-effective adjunct to existing psychosocial treatments. Trial Registration: NCT02246426.

Supplementing intensive targeted computerized cognitive training with social cognitive exercises for people with schizophrenia: An interim report

OBJECTIVE

Individuals with schizophrenia demonstrate cognitive, social cognitive, and motivational deficits that contribute to impairment in real-world functioning. In the current study, we investigated the effects of supplementing computerized neurocognitive training with social cognitive exercises, as compared with neurocognitive training alone.

METHOD

In this ongoing, double-blind, randomized controlled trial of 111 participants with psychosis, we compare the effects of supplementing intensive targeted cognitive training with social cognitive training exercises (TCT + SCT) with the effects of targeted cognitive training alone (TCT-only). Participants were assessed on cognition, symptoms, functional capacity, and functional outcomes, as well as social cognition and measures related to reward processing.

RESULTS

Both treatment groups showed significant improvement in multiple cognitive domains and improvement in functional capacity. However, as predicted, TCT + SCT group participants showed significant improvement in prosody identification and reward processing relative to TCT-only participants.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Our findings indicate that supplementing intensive computerized cognitive training with social cognitive exercises in people with psychosis confers greater benefits in prosody identification and reward processing relative to cognitive training alone, even though both approaches drive significant improvements in cognition and functional capacity. Impairments in both prosody identification and reward processing have been associated with greater negative symptoms and poorer functional outcomes in schizophrenia, raising the possibility that this form of treatment may lead to better long-term outcomes than traditional cognitive training approaches. Follow-up assessments will determine whether results are durable and generalize over time to improvements in symptoms and functioning. (PsycINFO Database Record

Stimulus uncertainty and perceptual learning: similar principles govern auditory and visual learning

We examined the impact of variability in speech stimuli on improvement of general performance and on accessibility to low-level information as a function of practice. Listeners had to discriminate between two similar words in noise in two configurations that differed only in their low-level binaural information, which was either null or maximal. The difference in performance quantifies the use of binaural low-level information. These configurations were presented in three training protocols: in separate blocks; in a consistently interleaved manner; and in a randomly mixed manner. The first protocol enabled optimal use of the low-level binaural cues already at the first training session. The second, consistently interleaved protocol required more than one training session to reach the same performance. The final, mixed protocol did not enable optimal use of the low-level cues even after multi-session training. Interestingly, training with the first two protocols transferred to the mixed one. These results are in line with recent findings in the visual modality. In both modalities, the effects of variability on learning can be explained by the introduction of obstructions to a search mechanism going down along the sensory processing hierarchy, as suggested by the Reverse Hierarchy Theory.

Randomized controlled trial of computer-based treatment of social cognition in schizophrenia: the TRuSST trial protocol

BACKGROUND

Schizophrenia is a severe and chronic medical condition, characterized by positive and negative symptoms, as well as pervasive social cognitive deficits. Despite the functional significance of the social cognition deficits affecting many aspects of daily living, such as social relationships, occupational status, and independent living, there is still no effective treatment option for these deficits, which is applied as standard of care. To address this need, we developed a novel, internet-based training program that targets social cognition deficits in schizophrenia (SocialVille). Preliminary studies demonstrate the feasibility and initial efficacy of Socialville in schizophrenia patients (Nahum et al., 2014). The purpose of the current trial (referred to as the TReatment of Social cognition in Schizophrenia Trial or TRuSST) is to compare SocialVille to an active control training condition, include a larger sample of patients, and assess both social cognitive functioning, and functional outcomes.

METHODS/DESIGN

We will employ a multi-site, longitudinal, blinded, randomized controlled trial (RCT) design with a target sample of 128 patients with schizophrenia. Patients will perform, at their home or in clinic, 40 sessions of either the SocialVille training program or an active control computer game condition. Each session will last for 40-45 minutes/day, performed 3-5 days a week, over 10-12 weeks, totaling to 30 hours of training. Patients will be assessed on a battery of social cognitive, social functioning and functional outcomes immediately before training, mid-way through training (after 20 training sessions) and at the completion of the 40 training sessions.

DISCUSSION

The strengths of this protocol are that it tests an innovative, internet-based treatment that targets fundamental social cognitive deficits in schizophrenia, employs a highly sensitive and extensive battery of functional outcome measures, and incorporates a large sample size in an RCT design.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02246426 Registered 16 September 2014.

Creating Live Interactions to Mitigate Barriers (CLIMB): A Mobile Intervention to Improve Social Functioning in People With Chronic Psychotic Disorders

BACKGROUND

Numerous psychosocial interventions for individuals with chronic psychotic disorders (CPD) have shown positive effects on social cognitive and functional outcome measures. However, access to and engagement with these interventions remains limited. This is partly because these interventions require specially trained therapists, are not available in all clinical settings, and have a high scheduling burden for participants, usually requiring a commitment of several weeks. Delivering interventions remotely via mobile devices may facilitate access, improve scheduling flexibility, and decrease participant burden, thus improving adherence to intervention requirements. To address these needs, we designed the Creating Live Interactions to Mitigate Barriers (CLIMB) digital intervention, which aims to enhance social functioning in people with CPD. CLIMB consists of two treatment components: a computerized social cognition training (SCT) program and optimized remote group therapy (ORGT). ORGT is an innovative treatment that combines remote group therapy with group texting (short message service, SMS).

OBJECTIVES

The objectives of this single-arm study were to investigate the feasibility of delivering 6 weeks of CLIMB to people with CPD and explore the initial effects on outcomes.

METHODS

Participants were recruited, screened and enrolled via the Internet, and delivered assessments and interventions remotely using provided tablets (iPads). Participants were asked to complete 18 hours of SCT and to attend 6 remote group therapy sessions. To assess feasibility, adherence to study procedures, attrition rates, engagement metrics, and acceptability of the intervention were evaluated. Changes on measures of social cognition, quality of life, and symptoms were also explored.

RESULTS

In total, 27 participants were enrolled over 12 months. Remote assessments were completed successfully on 96% (26/27) of the enrolled participants. Retention in the 6-week trial was 78% (21/27). Of all the iPads used, 95% (22/23) were returned undamaged at the end of the intervention. Participants on average attended 84% of the group therapy sessions, completed a median of 9.5 hours of SCT, and posted a median of 5.2 messages per week on the group text chat. Participants rated CLIMB in the medium range in usability, acceptability, enjoyment, and perceived benefit. Participants showed significant improvements in emotion identification abilities for prosodic happiness (P=.001), prosodic happiness intensity (P=.04), and facial anger (P=.04), with large within-group effect sizes (d=.60 to d=.86). Trend-level improvements were observed on aspects of quality of life (P values less than .09). No improvements were observed for symptoms.

CONCLUSIONS

It is feasible and acceptable to remotely deliver an intervention aimed at enhancing social functioning in people with CPD using mobile devices. This approach may represent a scalable method to increase treatment access and adherence. Our pilot data also demonstrate within-group gains in some aspects of social cognition after 6 weeks of CLIMB. Future randomized controlled studies in larger samples should evaluate the extent to which CLIMB significantly improves social cognition, symptoms, and quality of life in CPD.

Six month durability of targeted cognitive training supplemented with social cognition exercises in schizophrenia

Background

Deficits in cognition, social cognition, and motivation are significant predictors of poor functional outcomes in schizophrenia. Evidence of durable benefit following social cognitive training is limited. We previously reported the effects of 70 h of targeted cognitive training supplemented with social cognitive exercises (TCT + SCT) verses targeted cognitive training alone (TCT). Here, we report the effects six months after training.

Methods

111 participants with schizophrenia spectrum disorders were randomly assigned to TCT + SCT or TCT-only. Six months after training, thirty-four subjects (18 TCT + SCT, 16 TCT-only) were assessed on cognition, social cognition, reward processing, symptoms, and functioning. Intent to treat analyses was used to test the durability of gains, and the association of gains with improvements in functioning and reward processing were tested.

Results

Both groups showed durable improvements in multiple cognitive domains, symptoms, and functional capacity. Gains in global cognition were significantly associated with gains in functional capacity. In the TCT + SCT group, participants showed durable improvements in prosody identification and reward processing, relative to the TCT-only group. Gains in reward processing in the TCT + SCT group were significantly associated with improvements in social functioning.

Conclusions

Both TCT + SCT and TCT-only result in durable improvements in cognition, symptoms, and functional capacity six months post-intervention. Supplementing TCT with social cognitive training offers greater and enduring benefits in prosody identification and reward processing. These results suggest that novel cognitive training approaches that integrate social cognitive exercises may lead to greater improvements in reward processing and functioning in individuals with schizophrenia.

Psychological Resilience, Mental Health, and Inhibitory Control Among Youth and Young Adults Under Stress

Psychological resilience allows one to cope successfully with adversities occurring during stressful periods, which may otherwise trigger mental illness. Recent models suggest that inhibitory control (IC), the executive control function which supports our goal-directed behavior and regulates our emotional response, may underlie resilience. However, the ways in which this is manifested during stressful situations in real life is still unclear. Here, we examined the relationship between IC, psychological resilience, psychological distress, and anxiety among 138 female and male participants in a stressful situation: during their initial combat training in the military. Using a mobile app, we assessed IC using emotional and non-emotional variations of the Go/No-Go task. Psychological resilience, psychological distress, and anxiety were assessed using mobile versions of self-report questionnaires. We found that psychological resilience is significantly correlated with non-emotional IC (r = 0.24, p < 0.005), but not with emotional IC; whereas, psychological distress and anxiety are correlated with emotional IC (r = -0.253, p < 0.005 and r = -0.224, p < 0.01, for psychological distress and anxiety, respectively), but not with non-emotional IC. A regression model predicting emotional IC confirmed non-emotional IC and distress as unique contributors to the variance, but not psychological distress. In addition, associations between psychological distress and emotional IC were found only for female participants. Collectively, the results clarify the link between IC, resilience, and mental health in real-life stressful situations, showing separate mechanisms of IC involved in resilience on the one hand, and mental health on the other hand. These results have implications for building mobile resilience interventions for youth and young adults facing stressful situations.

Emotional dysregulation and health related quality of life in young adults with ADHD: a cross sectional study

Objective

Attention Deficit Hyperactivity Disorder (ADHD) is associated with emotional dysregulation (ED) and impaired health related quality of life (HRQoL). However, the role of ED in explaining the relationship between ADHD and HRQoL is unclear. The purpose of the present study was to do so in a sample of non-referred young adults with and without ADHD.

Method

The study design was cross-sectional. A non-clinical sample of 63 young adults with ADHD (mean age = 24.86 years, SD = 3.25, 78% university students) and 69 gender-matched controls (mean age = 23.84 years, SD = 2.59, 89% university students) were recruited. The Adult ADHD Quality-of-Life scale was used to measure HRQoL; The Self-Report Wender–Reimherr Adult Attention Deficit Disorder Scale and the Difficulties in Emotion Regulation Scale were used to measure ED. Group differences on all measures were tested using univariate and multivariate analyses of covariance, while controlling for age. Finally, a moderation analysis was used in order to examine the impact of ED on HRQoL beyond that accounted for by ADHD symptoms.

Results

Both HRQoL and ED were significantly worse for the ADHD group compared to the control group. The medication status of the ADHD group participants had no significant effect on the level of ADHD symptoms, ED or HRQoL. ED moderated the effect of ADHD symptoms on HRQoL for the ADHD group.

Conclusion

The findings support the centrality of ED in ADHD and its crucial influence on HRQoL. Young adults with ADHD and high levels of ED are at risk for aversive impact on their well-being regardless of their ADHD symptoms level.

Young adults with Attention Deficit Hyperactivity Disorder (ADHD) struggle with poor quality of life (QoL). Emotional regulation is one’s ability to modify their emotional state to promote adaptive, goal-oriented behaviors. Emotional dysregulation is a common yet neglected feature of people with ADHD. Our results show that young adults with ADHD are twice more likely to suffer from emotional dysregulation then their peers. Moreover, higher levels of emotional dysregulation predicted lower levels of QoL. These findings support the centrality of ED in ADHD and their crucial influence on everyday QoL. These findings are important not only on the theoretical level, but may also contribute to the design of interventions that aim to promote quality of life.

Examining the Effect of Transcranial Electrical Stimulation and Cognitive Training on Processing Speed in Pediatric Attention Deficit Hyperactivity Disorder: A Pilot Study

Objective

Processing Speed (PS), the ability to perceive and react fast to stimuli in the environment, has been shown to be impaired in children with attention deficit hyperactivity disorder (ADHD). However, it is unclear whether PS can be improved following targeted treatments for ADHD. Here we examined potential changes in PS following application of transcranial electric stimulation (tES) combined with cognitive training (CT) in children with ADHD. Specifically, we examined changes in PS in the presence of different conditions of mental fatigue.

Methods

We used a randomized double-blind active-controlled crossover study of 19 unmedicated children with ADHD. Participants received either anodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (dlPFC) or transcranial random noise stimulation (tRNS), while completing CT, and the administration order was counterbalanced. PS was assessed before and after treatment using the MOXO-CPT, which measures PS in the presence of various conditions of mental fatigue and cognitive load.

Results

tRNS combined with CT yielded larger improvements in PS compared to tDCS combined with CT, mainly under condition of increased mental fatigue. Further improvements in PS were also seen in a 1-week follow up testing.

Conclusion

This study provides initial support for the efficacy of tRNS combined with CT in improving PS in the presence of mental fatigue in pediatric ADHD.

Development and testing of a web-based battery to remotely assess cognitive health in individuals with schizophrenia

Cognitive impairment in schizophrenia is often severe, enduring, and contributes significantly to chronic disability. A standardized platform for identifying cognitive impairments and measuring treatment effects in cognition is a critical aspect of comprehensive evaluation and treatment for individuals with schizophrenia. In this project, we developed and tested a suite of ten web-based, neuroscience-informed cognitive assessments that are designed to enable the interpretation of specific deficits that could signal that an individual is experiencing cognitive difficulties. The assessment suite assays speed of processing, sustained attention, executive functioning, learning and socio-affective processing in the auditory and visual modalities. We have obtained data from 283 healthy individuals who were recruited online and 104 individuals with schizophrenia who also completed formal neuropsychological testing. Our data show that the assessments 1) are acceptable and tolerable to users, with successful completion in an average of under 40 min; 2) reliably measure the distinct theoretical cognitive constructs they were designed to assess; 3) can discriminate schizophrenia patients from healthy controls with a fair degree of accuracy (AUROC > 0.70); and 4) have promising construct, convergent, and external validity. Further optimization and validation work is in progress to finalize the evaluation process prior to promoting the dissemination of these assessments in real-world settings.

Transcranial random noise stimulation combined with cognitive training for treating ADHD: a randomized, sham-controlled clinical trial

Non-invasive brain stimulation has been suggested as a potential treatment for improving symptomology and cognitive deficits in Attention-Deficit/Hyperactivity Disorder (ADHD), the most common childhood neurodevelopmental disorder. Here, we examined whether a novel form of stimulation, high-frequency transcranial random noise stimulation (tRNS), applied with cognitive training (CT), may impact symptoms and neural oscillations in children with ADHD. We conducted a randomized, double-blind, sham-controlled trial in 23 unmedicated children with ADHD, who received either tRNS over the right inferior frontal gyrus (rIFG) and left dorsolateral prefrontal cortex (lDLPFC) or sham stimulation for 2 weeks, combined with CT. tRNS + CT yielded significant clinical improvements (reduced parent-reported ADHD rating-scale scores) following treatment, compared to the control intervention. These improvements did not change significantly at a 3-week follow-up. Moreover, resting state (RS)-EEG periodic beta bandwidth of the extracted peaks was reduced in the experimental compared to control group immediately following treatment, with further reduction at follow-up. A lower aperiodic exponent, which reflects a higher cortical excitation/inhibition (E/I) balance and has been related to cognitive improvement, was seen in the experimental compared to control group. This replicates previous tRNS findings in adults without ADHD but was significant only when using a directional hypothesis. The experimental group further exhibited longer sleep onset latencies and more wake-up times following treatment compared to the control group. No significant group differences were seen in executive functions, nor in reported adverse events. We conclude that tRNS + CT has a lasting clinical effect on ADHD symptoms and on beta activity. These results provide a preliminary direction towards a novel intervention in pediatric ADHD.

The association between implicit and explicit affective inhibitory control, rumination and depressive symptoms

Inhibitory control underlies one's ability to maintain goal-directed behavior by inhibiting prepotent responses or ignoring irrelevant information. Recent models suggest that impaired inhibition of negative information may contribute to depressive symptoms, and that this association is mediated by rumination. However, the exact nature of this association, particularly in non-clinical samples, is unclear. The current study assessed the relationship between inhibitory control over emotional vs. non-emotional information, rumination and depressive symptoms. A non-clinical sample of 119 participants (mean age: 36.44 ± 11.74) with various levels of depressive symptoms completed three variations of a Go/No-Go task online; two of the task variations required either explicit or implicit processing of emotional expressions, and a third variation contained no emotional expressions (i.e., neutral condition). We found reductions in inhibitory control for participants reporting elevated symptoms of depression on all three task variations, relative to less depressed participants. However, for the task variation that required implicit emotion processing, depressive symptoms were associated with inhibitory deficits for sad and neutral, but not for happy expressions. An exploratory analysis showed that the relationship between inhibition and depressive symptoms occurs in part through trait rumination for all three tasks, regardless of emotional content. Collectively, these results indicate that elevated depressive symptoms are associated with both a general inhibitory control deficit, as well as affective interference from negative emotions, with implications for the assessment and treatment of mood disorders.