Elevated Background Noise in Adult Attention Deficit Hyperactivity Disorder Is Associated with Inattention

Abstract

BackgroundInattention and distractibility are core symptoms of attention deficit hyperactivity disorder (ADHD). Still the neuronal organization is largely unknown. Previously we studied the electrophysiological activity of a distinct neuronal network—the retina—and found no change in stimulus-driven neural activity in patients with ADHD. However there is growing evidence for an elevated non stimulus-driven neural activity, or neuronal background noise, as underlying pathophysiological correlate. To further examine the biological bases that might underlie ADHD and problems with inattention, we performed a new analysis to test the hypothesis of an elevated background noise as underlying neuronal correlate for ADHD and problems with inattention in humans. A direct measure of background noise in patients with ADHD has not been described yet.MethodsThe retinal background noise was assessed based on pattern electroretinogram (PERG) data in 20 unmedicated ADHD patients and 20 healthy controls. The PERG is an electrophysiological measure for retinal ganglion cell function. ADHD severity was assessed by interview and questionnaire.ResultsNoise amplitude was significantly higher (138%) in patients with ADHD compared to the control group (p = 0.0047). Noise amplitude correlated significantly with psychometric measures for ADHD (CAARS) especially inattention (r = 0.44, p = 0.004).ConclusionsThe data provide evidence that an elevated background noise is associated with symptoms of inattention in ADHD and support the use of therapeutic interventions that reduce noise and distraction in patients with ADHD.

Normal Visual Acuity and Electrophysiological Contrast Gain in Adults with High-Functioning Autism Spectrum Disorder

“…In a series of experiments, we analyzed various early visual signals of different neuropsychiatric conditions to explore the possible objective markers of these conditions. In ADHD, a neurodevelopmental disorder with close associations with ASD, we found alterations in the electrophysiological measures of retinal background noise (Bubl et al, 2015a ). In depression, a frequent comorbidity of adult ASD, we found the electrophysiological retinal contrast gain to be significantly reduced (Bubl et al, 2015b ), as measured by the pattern electroretinogram (PERG) (Bubl et al, 2010 ) and VEP (Bubl et al, 2015b ).…”

“…Since the average of the two adjacent frequencies above and below the response frequency is an even better estimator of background noise (Meigen and Bach, 1999 ), this method was employed here. The overall background noise ratio was established using the average noise level across all contrast levels and both eyes (Bubl et al, 2015a ).…”

Atypically larger variability of resource allocation accounts for visual working memory deficits in schizophrenia

“…Third, it has been well-documented that neural variability plays an important role in perceptual and cognitive processing even without top-down modulations [67,68]. and abnormal levels of variability have been found in several other mental diseases [38][39][40][41]. Also, a recent study…”

Psychiatric Illnesses as Disorders of Network Dynamics

“…Diminished variability in mental states has also been described in higher age (103). On the other hand, a highly chaotic regime with its sensitivity to perturbations may account for attentional problems and a high distractibility by external stimuli, as, e.g., observed in ADHD (49,104).…”