scholarly journals A linguistic representation in the visual system underlies successful lipreading

2021 ◽  
Author(s):  
Aaron R Nidiffer ◽  
Cody Zhewei Cao ◽  
Aisling O’Sullivan ◽  
Edmund C Lalor
Keyword(s):  
Visual System ◽  
Speech Processing ◽  
Visual Processing ◽  
Visual Speech ◽  
Audiovisual Speech ◽  
Linguistic Processing ◽  
Audiovisual Speech Perception ◽  
Early Visual Processing ◽  
Linguistic Units ◽  
Basic Level

AbstractThere is considerable debate over how visual speech is processed in the absence of sound and whether neural activity supporting lipreading occurs in visual brain areas. Surprisingly, much of this ambiguity stems from a lack of behaviorally grounded neurophysiological findings. To address this, we conducted an experiment in which human observers rehearsed audiovisual speech for the purpose of lipreading silent versions during testing. Using a combination of computational modeling, electroencephalography, and simultaneously recorded behavior, we show that the visual system produces its own specialized representation of speech that is 1) well-described by categorical linguistic units (“visemes”) 2) dissociable from lip movements, and 3) predictive of lipreading ability. These findings contradict a long-held view that visual speech processing co-opts auditory cortex after early visual processing stages. Consistent with hierarchical accounts of visual and audiovisual speech perception, our findings show that visual cortex performs at least a basic level of linguistic processing.

scholarly journals Increased connectivity among sensory and motor regions during visual and audiovisual speech perception

2020 ◽  
Author(s):  
Jonathan E Peelle ◽  
Brent Spehar ◽  
Michael S Jones ◽  
Sarah McConkey ◽  
Joel Myerson ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Speech Perception ◽  
Brain Activity ◽  
Premotor Cortex ◽  
Temporal Cortex ◽  
Primary Auditory Cortex ◽  
Visual Speech ◽  
Auditory Signal ◽  
Audiovisual Speech ◽  
Audiovisual Speech Perception

In everyday conversation, we usually process the talker's face as well as the sound of their voice. Access to visual speech information is particularly useful when the auditory signal is degraded. Here we used fMRI to monitor brain activity while adults (n = 60) were presented with visual-only, auditory-only, and audiovisual words. As expected, audiovisual speech perception recruited both auditory and visual cortex, with a trend towards increased recruitment of premotor cortex in more difficult conditions (for example, in substantial background noise). We then investigated neural connectivity using psychophysiological interaction (PPI) analysis with seed regions in both primary auditory cortex and primary visual cortex. Connectivity between auditory and visual cortices was stronger in audiovisual conditions than in unimodal conditions, including a wide network of regions in posterior temporal cortex and prefrontal cortex. Taken together, our results suggest a prominent role for cross-region synchronization in understanding both visual-only and audiovisual speech.

Sound Location Can Influence Audiovisual Speech Perception When Spatial Attention Is Manipulated

2011 ◽  
Vol 24 (1) ◽  
pp. 67-90 ◽  
Author(s):  
Riikka Möttönen ◽  
Kaisa Tiippana ◽  
Mikko Sams ◽  
Hanna Puharinen
Keyword(s):  
Speech Perception ◽  
Spatial Attention ◽  
Reaction Times ◽  
Mcgurk Effect ◽  
Visual Speech ◽  
Audiovisual Speech ◽  
Sound Location ◽  
Audiovisual Speech Perception ◽  
The Right ◽  
Talking Face

AbstractAudiovisual speech perception has been considered to operate independent of sound location, since the McGurk effect (altered auditory speech perception caused by conflicting visual speech) has been shown to be unaffected by whether speech sounds are presented in the same or different location as a talking face. Here we show that sound location effects arise with manipulation of spatial attention. Sounds were presented from loudspeakers in five locations: the centre (location of the talking face) and 45°/90° to the left/right. Auditory spatial attention was focused on a location by presenting the majority (90%) of sounds from this location. In Experiment 1, the majority of sounds emanated from the centre, and the McGurk effect was enhanced there. In Experiment 2, the major location was 90° to the left, causing the McGurk effect to be stronger on the left and centre than on the right. Under control conditions, when sounds were presented with equal probability from all locations, the McGurk effect tended to be stronger for sounds emanating from the centre, but this tendency was not reliable. Additionally, reaction times were the shortest for a congruent audiovisual stimulus, and this was the case independent of location. Our main finding is that sound location can modulate audiovisual speech perception, and that spatial attention plays a role in this modulation.

Reducing Playback Rate of Audiovisual Speech Leads to a Surprising Decrease in the McGurk Effect

2018 ◽  
Vol 31 (1-2) ◽  
pp. 19-38 ◽  
Author(s):  
John F. Magnotti ◽  
Debshila Basu Mallick ◽  
Michael S. Beauchamp
Keyword(s):  
Visual Information ◽  
Mcgurk Effect ◽  
Visual Speech ◽  
Large Individual ◽  
Audiovisual Speech ◽  
Unexpected Finding ◽  
Video Playback ◽  
Natural Rate ◽  
Audiovisual Speech Perception ◽  
Bayesian Integration

We report the unexpected finding that slowing video playback decreases perception of the McGurk effect. This reduction is counter-intuitive because the illusion depends on visual speech influencing the perception of auditory speech, and slowing speech should increase the amount of visual information available to observers. We recorded perceptual data from 110 subjects viewing audiovisual syllables (either McGurk or congruent control stimuli) played back at one of three rates: the rate used by the talker during recording (the natural rate), a slow rate (50% of natural), or a fast rate (200% of natural). We replicated previous studies showing dramatic variability in McGurk susceptibility at the natural rate, ranging from 0–100% across subjects and from 26–76% across the eight McGurk stimuli tested. Relative to the natural rate, slowed playback reduced the frequency of McGurk responses by 11% (79% of subjects showed a reduction) and reduced congruent accuracy by 3% (25% of subjects showed a reduction). Fast playback rate had little effect on McGurk responses or congruent accuracy. To determine whether our results are consistent with Bayesian integration, we constructed a Bayes-optimal model that incorporated two assumptions: individuals combine auditory and visual information according to their reliability, and changing playback rate affects sensory reliability. The model reproduced both our findings of large individual differences and the playback rate effect. This work illustrates that surprises remain in the McGurk effect and that Bayesian integration provides a useful framework for understanding audiovisual speech perception.

scholarly journals “Paying” attention to audiovisual speech: Do incongruent stimuli incur greater costs?

2019 ◽  
Author(s):  
Violet Aurora Brown ◽  
Julia Feld Strand
Keyword(s):  
Speech Processing ◽  
Response Times ◽  
Audiovisual Integration ◽  
Mcgurk Effect ◽  
Visual Speech ◽  
Visual Signal ◽  
Audiovisual Speech ◽  
Dual Task Paradigm ◽  
Cortical Regions ◽  
Illusory Percept

The McGurk effect is a multisensory phenomenon in which discrepant auditory and visual speech signals typically result in an illusory percept (McGurk & MacDonald, 1976). McGurk stimuli are often used in studies assessing the attentional requirements of audiovisual integration (e.g., Alsius et al., 2005), but no study has directly compared the costs associated with integrating congruent versus incongruent audiovisual speech. Some evidence suggests that the McGurk effect may not be representative of naturalistic audiovisual speech processing—susceptibility to the McGurk effect is not associated with the ability to derive benefit from the addition of the visual signal (Van Engen et al., 2017), and distinct cortical regions are recruited when processing congruent versus incongruent speech (Erickson et al., 2014). In two experiments, one using response times to identify congruent and incongruent syllables and one using a dual-task paradigm, we assessed whether congruent and incongruent audiovisual speech incur different attentional costs. We demonstrated that response times to both the speech task (Experiment 1) and a secondary vibrotactile task (Experiment 2) were indistinguishable for congruent compared to incongruent syllables, but McGurk fusions were responded to more quickly than McGurk non-fusions. These results suggest that despite documented differences in how congruent and incongruent stimuli are processed (Erickson et al., 2014; Van Engen, Xie, & Chandrasekaran, 2017), they do not appear to differ in terms of processing time or effort. However, responses that result in McGurk fusions are processed more quickly than those that result in non-fusions, though attentional cost is comparable for the two response types.

scholarly journals Audiovisual speech perception and word recognition

2007 ◽  
pp. 18-36 ◽  
Author(s):  
Dominic W. Massaro ◽  
Alexandra Jesse
Keyword(s):  
Speech Perception ◽  
Word Recognition ◽  
Language Learning ◽  
Visual Speech ◽  
Audiovisual Speech ◽  
Audiovisual Speech Perception ◽  
Main Research ◽  
Face To Face ◽  
Facial Information ◽  
Communication Methods

This article gives an overview of the main research questions and findings unique to audiovisual speech perception research, and discusses what general questions about speech perception and cognition the research in this field can answer. The influence of a second perceptual source in audiovisual speech perception compared to auditory speech perception immediately necessitates the question of how the information from the different perceptual sources is used to reach the best overall decision. The article explores how our understanding of speech benefits from having the speaker's face present, and how this benefit makes transparent the nature of speech perception and word recognition. Modern communication methods such as Voice over Internet Protocol find a wide acceptance, but people are reluctant to forfeit face-to-face communication. The article also considers the role of visual speech as a language-learning tool in multimodal training, information and information processing in audiovisual speech perception, lexicon and word recognition, facial information for speech perception, and theories of audiovisual speech perception.

scholarly journals Hearing Lips and Seeing Voices: the Origins and Development of the ‘McGurk Effect’ and Reflections on Audio–Visual Speech Perception Over the Last 40 Years

2018 ◽  
Vol 31 (1-2) ◽  
pp. 7-18 ◽  
Author(s):  
John MacDonald
Keyword(s):  
Speech Perception ◽  
Visual Illusion ◽  
Simultaneous Presentation ◽  
Mcgurk Effect ◽  
Visual Speech ◽  
Audiovisual Speech ◽  
Audiovisual Speech Perception ◽  
Profound Impact ◽  
Visual Speech Perception

In 1976 Harry McGurk and I published a paper in Nature, entitled ‘Hearing Lips and Seeing Voices’. The paper described a new audio–visual illusion we had discovered that showed the perception of auditorily presented speech could be influenced by the simultaneous presentation of incongruent visual speech. This hitherto unknown effect has since had a profound impact on audiovisual speech perception research. The phenomenon has come to be known as the ‘McGurk effect’, and the original paper has been cited in excess of 4800 times. In this paper I describe the background to the discovery of the effect, the rationale for the generation of the initial stimuli, the construction of the exemplars used and the serendipitous nature of the finding. The paper will also cover the reaction (and non-reaction) to the Nature publication, the growth of research on, and utilizing the ‘McGurk effect’ and end with some reflections on the significance of the finding.

scholarly journals The neural basis for auditory and audiovisual speech perception

2019 ◽  
Author(s):  
Jonathan E. Peelle
Keyword(s):  
Speech Perception ◽  
Speech Processing ◽  
Temporal Cortex ◽  
Visual Signals ◽  
Acoustic Properties ◽  
Neural Systems ◽  
Audiovisual Speech ◽  
Human Communication ◽  
Neural Basis ◽  
Audiovisual Speech Perception

Understanding the neural systems supporting speech perception can shed light on the representations, processes, and variability in human communication. In the case of speech and language disorders, uncovering the neurological underpinnings can sometimes lead to surgical or medical treatments. Even in the case of healthy listeners, better understanding the interactions among hierarchical brain systems during speech processing can deepen our understanding of perceptual and language processes, and how these might be affected during development, hearing loss, or in background noise. Current neurobiological frameworks largely agree on the importance of bilateral temporal cortex for processing auditory speech, with the addition of left frontal cortex for more complex linguistic structures (such as sentences). Although visual cortex is clearly important for audiovisual speech processing, there is continued debate about where and how auditory and visual signals are integrated. Studies offer evidence supporting multisensory roles for posterior superior temporal sulcus, auditory cortex, and motor cortex. Rather than a single integration mechanism, it may be that visual and auditory inputs are combined in different ways depending on the type of information being processed. Importantly, core speech regions are not always sufficient for successfully understanding spoken language. Increased linguistic complexity or acoustic challenge forces listeners to recruit additional neural systems. In many cases compensatory activity is seen in executive and attention systems, such as the cingulo-opercular or frontoparietal networks. These patterns of increased activity appear to depend on the auditory and cognitive abilities of individual listeners, indicating a systems-level balance between neural systems that dynamically adjusts to the acoustic properties of the speech and current task demand. Speech perception is thus a shining example of flexible neural processing and behavioral stability.

scholarly journals The integration of continuous audio and visual speech in a cocktail-party environment depends on attention

2021 ◽  
Author(s):  
Farhin Ahmed ◽  
Aaron R. Nidiffer ◽  
Aisling E. O’Sullivan ◽  
Nathaniel J. Zuk ◽  
Edmund C. Lalor
Keyword(s):  
Multisensory Integration ◽  
Speech Processing ◽  
Visual Information ◽  
Visual Speech ◽  
Audiovisual Speech ◽  
Complex Environments ◽  
Cocktail Party ◽  
Levels Of Processing ◽  
Attention Task ◽  
Eeg Data

AbstractIn noisy, complex environments, our ability to understand audio speech benefits greatly from seeing the speaker’s face. This is attributed to the brain’s ability to integrate audio and visual information, a process known as multisensory integration. In addition, selective attention to speech in complex environments plays an enormous role in what we understand, the so-called cocktail-party phenomenon. But how attention and multisensory integration interact remains incompletely understood. While considerable progress has been made on this issue using simple, and often illusory (e.g., McGurk) stimuli, relatively little is known about how attention and multisensory integration interact in the case of natural, continuous speech. Here, we addressed this issue by analyzing EEG data recorded from subjects who undertook a multisensory cocktail-party attention task using natural speech. To assess multisensory integration, we modeled the EEG responses to the speech in two ways. The first assumed that audiovisual speech processing is simply a linear combination of audio speech processing and visual speech processing (i.e., an A+V model), while the second allows for the possibility of audiovisual interactions (i.e., an AV model). Applying these models to the data revealed that EEG responses to attended audiovisual speech were better explained by an AV model than an A+V model, providing evidence for multisensory integration. In contrast, unattended audiovisual speech responses were best captured using an A+V model, suggesting that multisensory integration is suppressed for unattended speech. Follow up analyses revealed some limited evidence for early multisensory integration of unattended AV speech, with no integration occurring at later levels of processing. We take these findings as evidence that the integration of natural audio and visual speech occurs at multiple levels of processing in the brain, each of which can be differentially affected by attention.

scholarly journals Neurophysiological indices of audiovisual speech integration are enhanced at the phonetic level for speech in noise

2020 ◽  
Author(s):  
Aisling E. O’Sullivan ◽  
Michael J. Crosse ◽  
Giovanni M. Di Liberto ◽  
Alain de Cheveigné ◽  
Edmund C. Lalor
Keyword(s):  
Speech Processing ◽  
Visual Cues ◽  
Audiovisual Integration ◽  
Visual Speech ◽  
Audiovisual Speech ◽  
Speech Comprehension ◽  
Speech In Noise ◽  
Multisensory Enhancement ◽  
Phonetic Features ◽  
Multiple Stages

AbstractSeeing a speaker’s face benefits speech comprehension, especially in challenging listening conditions. This perceptual benefit is thought to stem from the neural integration of visual and auditory speech at multiple stages of processing, whereby movement of a speaker’s face provides temporal cues to auditory cortex, and articulatory information from the speaker’s mouth can aid recognizing specific linguistic units (e.g., phonemes, syllables). However it remains unclear how the integration of these cues varies as a function of listening conditions. Here we sought to provide insight on these questions by examining EEG responses to natural audiovisual, audio, and visual speech in quiet and in noise. Specifically, we represented our speech stimuli in terms of their spectrograms and their phonetic features, and then quantified the strength of the encoding of those features in the EEG using canonical correlation analysis. The encoding of both spectrotemporal and phonetic features was shown to be more robust in audiovisual speech responses then what would have been expected from the summation of the audio and visual speech responses, consistent with the literature on multisensory integration. Furthermore, the strength of this multisensory enhancement was more pronounced at the level of phonetic processing for speech in noise relative to speech in quiet, indicating that listeners rely more on articulatory details from visual speech in challenging listening conditions. These findings support the notion that the integration of audio and visual speech is a flexible, multistage process that adapts to optimize comprehension based on the current listening conditions.Significance StatementDuring conversation, visual cues impact our perception of speech. Integration of auditory and visual speech is thought to occur at multiple stages of speech processing and vary flexibly depending on the listening conditions. Here we examine audiovisual integration at two stages of speech processing using the speech spectrogram and a phonetic representation, and test how audiovisual integration adapts to degraded listening conditions. We find significant integration at both of these stages regardless of listening conditions, and when the speech is noisy, we find enhanced integration at the phonetic stage of processing. These findings provide support for the multistage integration framework and demonstrate its flexibility in terms of a greater reliance on visual articulatory information in challenging listening conditions.

Sign in / Sign up

Export Citation Format

Share Document