Inattentional Deafness: Visual Load Leads to Time-Specific Suppression of Auditory Evoked Responses

Abstract

Due to capacity limits on perception, conditions of high perceptual load lead to reduced processing of unattended stimuli (Lavie et al., 2014). Accumulating work demonstrates the effects of visual perceptual load on visual cortex responses, but the effects on auditory processing remain poorly understood. Here we establish the neural mechanisms underlying "inattentional deafness"-the failure to perceive auditory stimuli under high visual perceptual load. Participants performed a visual search task of low (target dissimilar to nontarget items) or high (target similar to nontarget items) load. On a random subset (50%) of trials, irrelevant tones were presented concurrently with the visual stimuli. Brain activity was recorded with magnetoencephalography, and time-locked responses to the visual search array and to the incidental presence of unattended tones were assessed. High, compared to low, perceptual load led to increased early visual evoked responses (within 100 ms from onset). This was accompanied by reduced early (ϳ100 ms from tone onset) auditory evoked activity in superior temporal sulcus and posterior middle temporal gyrus. A later suppression of the P3 "awareness" response to the tones was also observed under high load. A behavioral experiment revealed reduced tone detection sensitivity under high visual load, indicating that the reduction in neural responses was indeed associated with reduced awareness of the sounds. These findings support a neural account of shared audiovisual resources, which, when depleted under load, leads to failures of sensory perception and awareness.

To hear or not to hear: Voice processing under visual load

“…It also parallels reports that irrelevant face processing is reduced under high load when attending another target face, but not when attending other target objects, such as houses or hands (Neumann, Mohamed, & Schweinberger, 2009, or letter strings, as in the standard perceptual-load task (Neumann & Schweinberger, 2008). Importantly, the present results are therefore not necessarily inconsistent with studies showing effects of visual perceptual load on auditory processing (Macdonald & Lavie, 2011;Molloy et al, 2015;Raveh & Lavie, 2015), as these studies used simple tones rather than voices as the task-irrelevant stimuli. Our findings are potentially related to evidence that the duration of visual motion aftereffects is also unaltered by auditory perceptual load (Rees et al, 2001), and to electrophysiological data that the mismatch negativity (MMN) to rare frequency or intensity changes of task-irrelevant tone pips is unaffected by the difficulty of a concurrent visual discrimination task (MullerGass, Stelmack, & Campbell, 2006).…”

“…Voice gender aftereffects, as induced by the ignored adaptor voices, were assessed by the perception of subsequent androgynous test voices as either male or female Accordingly, high relative to low perceptual load decreases the processing of task-irrelevant stimuli. For instance, inattentional deafness to simple tone stimuli can be induced by loading visual perceptual task demands (Macdonald & Lavie, 2011;Molloy et al, 2015;Raveh & Lavie, 2015). Accordingly, one might expect larger voice adaptation under low (vs. high) perceptual load in the present study, provided that attentional resources are shared by the target and distractor stimuli.…”

“…This account has received substantial support from studies on vision (reviewed in de Fockert, 2013;Lavie, 2005) and audition (Alain & Izenberg, 2003;Conway, Cowan, & Bunting, 2001;Dalton, Santangelo, & Spence, 2009;Fairnie, Moore, & Remington, 2016;Muller-Gass & Schröger, 2007; but see Murphy, Fraenkel, & Dalton, 2013), and from studies probing load theory for crossmodal attention (Berman & Colby, 2002;Brand-D'Abrescia & Lavie, 2008;Jacoby, Hall, & Mattingley, 2012;Macdonald & Lavie, 2011;Molloy, Griffiths, Chait, & Lavie, 2015;Raveh & Lavie, 2015; but see Tellinghuisen & Nowak, 2003). Interestingly, and at variance with load theory, several studies have suggested that faces present a special case, in the sense that they may recruit a domain-specific capacity-limited system (Neumann, Mohamed, & Schweinberger, 2011;Neumann & Schweinberger, 2008).…”

A roadmap for the study of conscious audition and its neural basis

“…To the extent that auditory and visual attention rely on shared resources, as is suggested by the global-workspace model [35] and others, attention to a visual task may concurrently reduce the processing depth of sound; evidence for this comes in the form of smaller auditory-evoked responses with enhanced visual attentional load [289]. However, the degree of response suppression is not as great as that found with informational masking [107], which is a within-modality (i.e.…”

Excessive noise in intensive care units

“…4 11 The cognitive cost associated with the subconscious processing of distractor noises limits the brain's ability to process auditory and visual information. 12 Desensitisation to background noise may reduce staff alertness. Up to 75% of alarms are false alerts, require no immediate action, or are simply ignored.…”