Stochastic resonance is not required for pink noise to have beneficial effects on ADHD-related performance? The moderate brain arousal model challenged.

OBJECTIVE

Random noise, such as white or pink noise, has been shown to have beneficial effects on the performance of individuals with (elevated traits of) ADHD. Both the state regulation deficit (SRD) account and the moderate brain arousal (MBA) model argue that this effect is due to enhanced cognitive arousal. The MBA model specifically attributes this to random noise affecting dopaminergic (DA) transmission via stochastic resonance (SR). However, he requirement of SR and the role of DA have not yet been properly examined. To test this, proper control conditions are needed.

METHOD

To examine the requirement of SR, 60 neurotypical adults with varying levels of ADHD traits performed a slow two-choice reaction time (S1-S2) task in three auditory conditions: pink (random) noise, a pure 100 Hz tone (non-random noise), and silence. All participants also completed the Attention Network Test (ANT) in two conditions (pink noise and silence) to inspect the effect on executive network efficiency which may serve as a proxy measure of DA. ADHD traits were assessed via self-report.

RESULTS

Auditory stimulation improved performance on the S1-S2 task in participants with elevated ADHD traits, however this was the case for both pink noise and the pure tone. Pink noise did not affect executive network efficiency, irrespective of ADHD traits.

CONCLUSIONS

Our results suggest that stochastic resonance is not required for pink noise to have a beneficial effect on ADHD-related performance. Pink noise did not affect our DA proxy measure, however this negative finding should be interpreted with caution. Our results cast doubt on the tenets of the MBA model, warranting further research.