Past research had suggested a link between white noise and learning in children with attention-deficit hyperactivity disorder and in people learning arithmetic. The new work, however, is the first to combine fMRI analysis with behavioral tests to understand the effects of white noise on memory in healthy adults.
In the new study published in the Journal of Cognitive Neuroscience, Vanessa Rausch, Eva Bauch, and Nico Bunzeck of the University Medical Center Hamburg-Eppendorf describe the effects of the white noise in the brain during a memory task. The researchers asked participants to remember gray-scale photos of various scenes while listening to either white noise, a sinus tone, no noise, or the sound of a horse running played backward.
In the first study, they found that the listening to the auditory white noise – heard as a “sh” sound – slightly improved memory of the images compared to when listening to the control sounds. In a second study, the researchers then looked at the brain activity while performing a memory task in the fMRI scanner.
“What really surprised me was the strength of effect of white noise in the mesolimbic midbrain,” Bunzeck says. This region of the brain corresponds to the pathway for dopamine – a neurotransmitter associated with reward.
The white noise enhanced connectivity in between brain regions associated with modulating dopamine and attention. The researchers found this enhanced connectivity in those participants with improved memory.
Bunzeck says that the findings suggest that white noise could be particularly useful to facilitate learning in people who have memory deficits caused by changes in the mesolimbic system, such as older adults.
Don’t rush out to play white noise to help boost your memory just yet, though. Bunzeck says that researchers still need to identify several factors that influence this link. “For instance, we suppose that some populations might benefit more than others – depending, for example, on personality or the structural integrity of their individual mesolimbic system,” he says. “Also, the effects of loudness and frequency range of auditory white noise might play an important role.”
Also, take care to note that the white noise in this study is not just any background sound, but a random signal in the auditory range that we hear as a “sh”. So working in a loud cafe would not necessarily yield the same beneficial results.
-Lisa M.P. Munoz
The paper, “White Noise Improves Learning by Modulating Activity in Dopaminergic Midbrain Regions and Right Superior Temporal Sulcus,” by Vanessa H. Rausch, Eva M. Bauch, and Nico Bunzeck, was published in the Journal of Cognitive Neuroscience online on Dec. 17, 2013.