Cortical signatures of auditory looming bias show cue-specific adaptation between newborns and young adults

Abstract

Adaptive biases in favor of approaching, or “looming”, sounds have been found across ages and species, thereby implicating the potential of their evolutionary origin and universal basis. The human auditory system is well-developed at birth, yet spatial hearing abilities further develop with age. To disentangle the speculated inborn, evolutionary component of the auditory looming bias from its learned counterpart, we collected high-density electroencephalographic data across human adults and newborns. As distance-motion cues we manipulated either the sound’s intensity or spectral shape, which is pinna-induced and thus prenatally inaccessible. Through cortical source localisation we demonstrated the emergence of the bias in both age groups at the level of Heschl’s gyrus. Adults exhibited the bias in both attentive and inattentive states; yet differences in amplitude and latency appeared based on attention and cue type. Contrary to the adults, in newborns the bias was elicited only through manipulations of intensity and not spectral cues. We conclude that the looming bias comprises innate components while flexibly incorporating the spatial cues acquired through lifelong exposure.

Threat-Related Corticocortical Connectivity Elicited by Rapid Auditory Looms

“…As INSIDEOUT is reflective of subjective conscious awareness [29], our result corroborates the difference in perception depending on cue type. The greater intervention of intensity stimuli, in terms of disruption in causal interactions, highlights their salience as already emerged through prior behavioral as well as neural studies [6,7,9,10,12,14,15,23,49,50]. The effects we found from the INSIDEOUT framework, although present, are small in size.…”

“…As an effective warning mechanism, the looming bias should have the capacity to readily capture attention and be rather universal across cue types. Corroborating this hypothesis, signatures of the bias have indeed been found across attentional states and auditory distance cue types; they were present already at the level of Heschl's gyrus (HG), housing the primary auditory cortex [10].…”

“…We extracted all ROI time series from the 68 areas of the atlas, as defined in Brainstorm. Based on the evoked time courses at the level of the transverse temporal gyrus, taken from [10], a time window of 300 ms post-change was defined as the time window of interest.…”

“…High spatial resolution is achieved by complementing source localisation of high-density EEG with individual brain anatomies and electrode locations [31]. The present analyses are based on prior collected data, studying the auditory looming bias at the level of HG under the aforementioned factors of attention and cue type [10]. In that paradigm (Fig.…”

“…As an effective warning mechanism, the looming bias should have the capacity to readily capture attention and be rather universal across cue types. Corroborating this hypothesis, signatures of the bias have indeed been found across attentional states and auditory distance cue types; they were present already at the level of Heschl’s gyrus (HG), housing the primary auditory cortex [10]. Yet the bias’ relationship to threat detection remained a hypothesis, and discrepancies in behavioral performance, timing, and attentional amplification, suggest that there are differences in cortical processing depending on these factors.…”