Fixating the eyes of a speaker provides sufficient visual information to modulate early auditory processing

Listen to resonate: Better listening as a gateway to interpersonal positivity resonance through enhanced sensory connection and perceived safety

Although often experienced individually, emotions are at times co-experienced with others, collectively. One type of collective emotion, termed positivity resonance, refers to coexperienced positive affect accompanied by caring non-verbal behavioral synchrony and biological synchrony across persons. Growing evidence illustrates the contributions of positivity resonance to individual, relational, and community well-being. Two conditions theorized as conducive for the emergence of positivity resonance are real-time sensory connection and perceived safety. Here, we explore listening as an interpersonal process that can serve to enhance real-time sensory connection and perceived safety and thereby increase positivity resonance among conversation partners. Specifically, we present evidence that connects listening to direct gaze (i.e., real-time sensory connection) and psychological safety (i.e., perceived safety). We close by offering a framework to guide future research that can test whether and how conversational listening functions to create more moments of positivity resonance in interpersonal contexts.

Lip-Reading Enables the Brain to Synthesize Auditory Features of Unknown Silent Speech

Lip-reading is crucial for understanding speech in challenging conditions. But how the brain extracts meaning from, silent, visual speech is still under debate. Lip-reading in silence activates the auditory cortices, but it is not known whether such activation reflects immediate synthesis of the corresponding auditory stimulus or imagery of unrelated sounds. To disentangle these possibilities, we used magnetoencephalography to evaluate how cortical activity in 28 healthy adult humans (17 females) entrained to the auditory speech envelope and lip movements (mouth opening) when listening to a spoken story without visual input (audio-only), and when seeing a silent video of a speaker articulating another story (video-only). In video-only, auditory cortical activity entrained to the absent auditory signal at frequencies <1 Hz more than to the seen lip movements. This entrainment process was characterized by an auditory-speech-to-brain delay of ∼70 ms in the left hemisphere, compared with ∼20 ms in audio-only. Entrainment to mouth opening was found in the right angular gyrus at <1 Hz, and in early visual cortices at 1-8 Hz. These findings demonstrate that the brain can use a silent lip-read signal to synthesize a coarse-grained auditory speech representation in early auditory cortices. Our data indicate the following underlying oscillatory mechanism: seeing lip movements first modulates neuronal activity in early visual cortices at frequencies that match articulatory lip movements; the right angular gyrus then extracts slower features of lip movements, mapping them onto the corresponding speech sound features; this information is fed to auditory cortices, most likely facilitating speech parsing.SIGNIFICANCE STATEMENT Lip-reading consists in decoding speech based on visual information derived from observation of a speaker's articulatory facial gestures. Lip-reading is known to improve auditory speech understanding, especially when speech is degraded. Interestingly, lip-reading in silence still activates the auditory cortices, even when participants do not know what the absent auditory signal should be. However, it was uncertain what such activation reflected. Here, using magnetoencephalographic recordings, we demonstrate that it reflects fast synthesis of the auditory stimulus rather than mental imagery of unrelated, speech or non-speech, sounds. Our results also shed light on the oscillatory dynamics underlying lip-reading.