Training sensory signal-to-noise resolution in children with ADHD in a global mental health setting

Abstract

Children with attention deficit/hyperactivity disorder (ADHD) have impaired focus on goal-relevant signals and fail to suppress goal-irrelevant distractions. To address both these issues, we developed a novel neuroplasticity-based training program that adaptively trains the resolution of challenging sensory signals and the suppression of progressively more challenging distractions. We evaluated this sensory signal-to-noise resolution training in a small sample, global mental health study in Indian children with ADHD. The children trained for 30 h over 6 months in a double-blind, randomized controlled trial. Training completers showed steady and significant improvements in ADHD-associated behaviors from baseline to post training relative to controls, and benefits sustained in a 6-month follow-up. Post-training cognitive assessments showed significant positive results for response inhibition and Stroop interference tests in training completers vs controls, while measures of sustained attention and short-term memory showed nonsignificant improvement trends. Further, training-driven improvements in distractor suppression correlated with the improved ADHD symptoms. This initial study suggests utility of signal-to-noise resolution training for children with ADHD; it emphasizes the need for further research on this intervention and substantially informs the design of a larger trial.

Conflict of interest statement

MMM is the President and Founder of Brain Plasticity Institute, Posit Science. AG is the co-founder and chief science advisor of Akili Interactive Labs. MMM has a patent for ‘Adaptive Set Discrimination Procedure' and JM, AG and MMM have a patent for 'Methods of Suppressing Irrelevant Stimuli' the ONTRAC program was developed based on these patents. RS declares no conflicts of interest.

Figures

Figure 1

Study design for the ONTRAC double-blind randomized controlled trial (ClinicalTrials.gov as NCT01772485). ADHD, attention deficit/hyperactivity disorder; ONTRAC, Online Neuroplasticity Targeted Remediation of Attention deficits in Children.

Figure 2

Flow through the ONTRAC program. The user enters the program (top right) and is provided a recap of accumulated rewards followed by a daily training mission. The user then continues to a dashboard of seven daily exercises that can be completed in a 30-min session. Daily exercise snapshots are shown. After session completion, the user's rank is updated along with progress through planetary missions and earned super powers. The user then returns to ‘Start' and accesses the next session. ONTRAC, Online Neuroplasticity Targeted Remediation of Attention deficits in Children.

Figure 3

Parent-based ADHD symptom severity ratings at baseline (Pre), mid-intervention (Mid, 3 months from Pre), post-intervention (Post, 6 months from Pre) and at follow-up (12 months from Pre). The children did not access their assigned intervention between the post-assessment and follow-up. Data points are average ratings for ONTRAC completers (n=11, in green) vs active control participants (n=7, in red); error bars are standard errors (s.e.m). * indicates that only the ONTRAC group showed significant and sustained improvement from baseline. At follow-up, the ONTRAC scores did not significantly differ from the scores in healthy children (dashed gray line represents upper 95% confidence interval of healthy ratings). ADHD, attention deficit/hyperactivity disorder; ONTRAC, Online Neuroplasticity Targeted Remediation of Attention deficits in Children.

Figure 4

Change in cognitive performance from baseline to post-intervention (post – pre change) in the ONTRAC (n=11, in green) and active control group (n=7, in red). Data are averages, error bars are s.e.m. For all measures, improvement from baseline is shown above zero vs decline below zero. Performance changes for sustained attention and response inhibition were measured by signal detection sensitivity (d′). For spatial and verbal short-term memory, performance changes are shown for response speed in seconds (faster speeds at the post-assessment yield negative change from baseline and reflect improvement). Change in the Stroop test was as per the Stroop interference score. Post–pre intervention change in ONTRAC completers significantly differed from controls for response inhibition and Stroop (P⩽0.05) but not attention and short-term memory (P<0.14). ONTRAC, Online Neuroplasticity Targeted Remediation of Attention deficits in Children.

Figure 5

Correlation between improvements in distractor processing (x axis) trained by ONTRAC (n=11 completers) and improvements in ADHD symptom severity (y axis). More negative post–pre changes reflect larger improvement for both measures. ADHD, attention deficit/hyperactivity disorder; ONTRAC, Online Neuroplasticity Targeted Remediation of Attention deficits in Children.