Signal-to-Noise Ratio Effects Frontoparietal Network Lateralization: Electroencephalogram Evidence in Underwater Auditory Target Recognition

Accurately recognizing auditory targets within background interference remains challenging at a low signal-to-noise ratio (SNR). Using an oddball paradigm, this electroencephalogram study investigated the impact of SNR (0, −10, and −20 dB) on psychophysiological processes underlying underwater auditory target recognition in twenty normal-hearing participants. Reduced SNR impaired the N1–P2 component and led to P300 variations, with delayed latencies (N1: p = 0.0355; P300: p = 0.0075) and reduced amplitudes (P2: p = 0.0075; P300: p = 0.0277), indicating increased attentional demands. Microstate analysis highlighted 300–400 ms frontoparietal activation for attention orientation and sensory information integration. Reduced accuracy correlates with alpha-band activity and phase variations over frontoparietal areas (event-related spectral perturbation [ERSP]: p = 0.0388; inter-trial coherence [ITC]: p = 0.0059), implying suppression of task-relevant processing. Gamma-band activity and phase at lower SNR levels suggest changes in the parietal network's function (ERSP: p = 0.0183; ITC: p = 0.0113), influencing reaction times due to increased integration difficulty. Right-lateralized alpha- and gamma-band network shifts support the functional advantages of the right hemisphere in noise, with enhanced local efficiency (frontal alpha: p = 0.0100; parietal—occipital gamma: p = 0.0116). These findings provide insights into the psychophysiological mechanisms underlying auditory target recognition in noise.