Suppressing unwanted background sound is crucial for aural communication. Public spaces often contain a particularly disruptive background sound, called informational masking (IM). At present, IM is identified operationally: when a target should be audible, based on suprathreshold target/masker energy ratios, yet cannot be heard because perceptually similar background sound interferes. Here, behavioral experiments combined with functional near infrared spectroscopy identify brain regions that predict individual vulnerability to IM. Results show that tasked-evoked blood oxygenation changes near the superior temporal gyrus (STG) and behavioral speech detection performance covary for same-ear IM background sound, suggesting that the STG is part of an IM-dependent network. Moreover, listeners who are more vulnerable to IM show an increased metabolic need for oxygen near STG. In contrast, task-evoked responses in a region of lateral frontal cortex, the caudal inferior frontal sulcus (cIFS), do not predict behavioral sensitivity, suggesting that the cIFS belongs to an IM-independent network.
bioRxiv Subject Collection: Neuroscience