Low intensity white noise improves performance in auditory working memory task: An fMRI study.

Area of Science:

• Cognitive Neuroscience
• Auditory Perception
• Neuroimaging

Background:

• White noise may improve auditory working memory via stochastic resonance (SR).
• SR is characterized by an inverted U-shaped relationship between noise intensity and performance.
• Optimal signal-to-noise ratio (SNR) for SR in auditory working memory remains under-investigated.

Purpose of the Study:

• To investigate the impact of various noise levels on auditory working memory performance.
• To map the inverted U-curve of SR in auditory working memory.
• To identify neural correlates of SR in auditory working memory using fMRI.

Main Methods:

• Twenty healthy young adults completed a backward recall span task.
• Participants performed the task under four SNR conditions: 15, 10, 5, and 0-dB.
• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.

Main Results:

• Behavioral performance and brain activation improved with moderate noise (10 and 5-dB SNR), but decreased at 0-dB SNR.
• fMRI and behavioral data confirmed an inverted U-shaped curve for noise benefit.
• Activity in the right superior frontal gyrus (SFG) positively correlated with performance at 5-dB SNR.

Conclusions:

• The study confirms stochastic resonance enhances auditory working memory.
• Optimal SNR for auditory working memory enhancement is between 5 and 10 dB.
• The right SFG is a critical region for noise-enhanced auditory working memory.