Attentional and emotional prioritization of the sounds occurring outside the visual field.

The ability to detect and localize sounds in an environment is critical for survival. Localizing sound sources is a computational challenge for the human brain because the auditory cortex seems to lack a topographical space representation. However, attention and task demands can modulate localization performance. Here, we investigated whether the localization performance for sounds occurring directly in front of or behind people could be modulated by emotional salience and sound-source location. We measured auditory-induced emotion by ecological sounds occurring in the frontal or rear perceptual fields, and employed a speeded localization task. The results showed that both localization speed and accuracy were higher, and that stronger negative emotions were induced when sound sources were behind the participants. Our results provide clear behavioral evidence that auditory attention can be influenced by sound-source location. Importantly, we also show that the effect of spatial location on attention is mediated by emotion, which is in line with the argument that emotional information is prioritized in processing. Auditory system functions as an alarm system and is in charge of detecting possible salient events, and alarming for an attention shift. Further, spatial processing in the auditory dorsal pathway has a function of guiding the visual system to a particular location of interest. Thus, an auditory bias toward the space outside the visual field can be useful, so that visual attention could be quickly shifted in case of emotionally significant information.