Mechanisms underlying the auditory looming bias: Neural substrate
Our auditory system constantly keeps track of our environment, informing us about our surroundings and warning us of potential threats. The auditory looming bias is an early perceptual effect, showing higher alertness of listeners to approaching auditory objects, compared to receding ones. Experimentally, this bias has been studied using stimuli varying in intensity as well as in spectral shape. Neural investigations with intensity-based stimuli argue for a top-down projection from the prefrontal cortex to the auditory cortex, prioritizing approaching over receding sonic motion. Here, we test the generalizability of those findings to looming bias elicited via spectral shape manipulation, while we further discuss the involvement of regions known to be crucial in sound motion processing. As such, our results suggest that the auditory looming bias underlies a more distributed network, largely overlapping with previous fMRI results. The current knowledge is further extended, by refining the temporal evolvement and direction of information flow between the network nodes.