Study Challenges Leading Theory on Pink Noise and ADHD Cognitive Benefits
A new study published today challenges a prominent explanation for why auditory stimulation, such as pink noise, can improve cognitive performance in individuals with traits of attention deficit hyperactivity disorder (ADHD).
Researchers at Ghent University found that both random noise and a non-random pure tone had similar effects on a brain activity measure linked to neural noise, contradicting key assumptions of the moderate brain arousal model. The study, appearing in the Journal of Attention Disorders, involved 69 neurotypical adults who completed assessments for ADHD traits while undergoing electroencephalogram (EEG) monitoring during periods of silence, pink noise exposure, and exposure to a continuous 100 Hz pure tone. Analysis focused on the aperiodic slope of the power spectral density, a measure reflecting background brain activity and neural noise.
Contrary to the moderate brain arousal model’s prediction of lower neural noise in those with ADHD traits, the study revealed individuals reporting more ADHD traits actually exhibited more background neural noise during silent periods. Furthermore, both pink noise and the pure tone led to a reduction in neural noise, challenging the theory that the benefits stem from a specific mechanism called stochastic resonance, which requires random signals. This finding suggests a more general effect on brain arousal may be at play, potentially aligning with the state regulation deficit account of ADHD, which posits difficulties in regulating arousal levels. Understanding the neurological basis of ADHD is crucial for developing more effective interventions.
Researchers acknowledge the study’s limitations, including its focus on neurotypical adults with varying ADHD traits and the use of a resting-state EEG. Future research will explore these brain activity patterns during cognitive tasks and in individuals with a formal ADHD diagnosis. The authors propose further investigation is needed to determine if the observed effects translate to real-world improvements in attention and focus, and to refine our understanding of how auditory stimulation impacts brain function.
