On how natural and urban soundscapes alter brain activity during cognitive performance

Listening to natural or urban soundscapes has previously been shown to differentially modulate performance in a subsequent cognitive task. The present study inquired the effect of listening to urban (traffic and machinery noise) vs. natural (birds, water and wind) soundscapes on cognitive performance, mood, stress reactivity and the consequences for brain activity during a cognitive task assessed before and after soundscape exposure. In a randomized experiment, 30 participants were exposed to three conditions on three separate testing days: urban, natural and no soundscape. Before and after the functional MRI session participants performed a dual n-back, a backward digit span task and filled out mood, stress reactivity and aesthetic preference questionnaires. The natural soundscapes did lead to better cognitive performance however, the effect did not reach significance. Exposure to the natural soundscapes resulted in a significant decrease of negative affect and participants rated them as significantly more aesthetic. On the brain level, listening to the urban soundscape was associated with an increase in superior temporal gyrus (STG) activity during the subsequent dual n-back task. However, this result was statistically not corrected and remains exploratory in nature. This result could potentially hint at information processing becoming less efficient in early primary sensory area as a result of exposure to the urban soundscape. Correlations between affect/cognition and task related brain activity revealed clusters in the attention-network.