An ecological investigation of the capacity to follow simultaneous speech and preferential detection of ones’ own name

Abstract

Many situations require focusing attention on one speaker, while monitoring the environment for potentially important information. Some have proposed that dividing attention among 2 speakers involves behavioral trade-offs, due to limited cognitive resources. However the severity of these trade-offs, particularly under ecologically-valid circumstances, is not well understood. We investigated the capacity to process simultaneous speech using a dual-task paradigm simulating task-demands and stimuli encountered in real-life. Participants listened to conversational narratives (Narrative Stream) and monitored a stream of announcements (Barista Stream), to detect when their order was called. We measured participants’ performance, neural activity, and skin conductance as they engaged in this dual-task. Participants achieved extremely high dual-task accuracy, with no apparent behavioral trade-offs. Moreover, robust neural and physiological responses were observed for target-stimuli in the Barista Stream, alongside significant neural speech-tracking of the Narrative Stream. These results suggest that humans have substantial capacity to process simultaneous speech and do not suffer from insufficient processing resources, at least for this highly ecological task-combination and level of perceptual load. Results also confirmed the ecological validity of the advantage for detecting ones’ own name at the behavioral, neural, and physiological level, highlighting the contribution of personal relevance when processing simultaneous speech.

Neural Speech-Tracking During Selective Attention and Attention-Switching Between Concurrent Talkers: a spatially realistic audiovisual study

“…One possibility is that the former-target speech is still highly salient to the listeners and therefore continues to be well represented and processed by the brain, even though it is no longer behaviorally relevant to them. This hypothesis suggests that after attention-switching, listeners employ more of a ‘divided attention’ listening strategy, relative to before the switch (Agmon et al, 2021; Kaufman & Zion Golumbic, 2023; Lambez et al, 2020; Pinto et al, 2023). A second possibility is that the attention-switch is highly effective and listeners are able to ‘tune out’ and suppress speech by the former-target talker, just as well as they suppressed the non-target talker before the switch.…”