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Multisensory and modality specific processing of visual speech in different regions of the premotor cortex.

Callan DE, Jones JA, Callan A - Front Psychol (2014)

Bottom Line: The left inferior parietal lobule and right cerebellum also showed these properties.The left ventral superior and dorsal premotor cortex (PMvs/PMd) did not show this multisensory enhancement effect, but there was greater activity for the visual only over audio-visual conditions in these areas.The results suggest that the inferior regions of the ventral premotor cortex are involved with integrating multisensory information, whereas, more superior and dorsal regions of the PMC are involved with mapping unimodal (in this case visual) sensory features of the speech signal with articulatory speech gestures.

View Article: PubMed Central - PubMed

Affiliation: Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka University Osaka, Japan ; Multisensory Cognition and Computation Laboratory Universal Communication Research Institute, National Institute of Information and Communications Technology Kyoto, Japan.

ABSTRACT
Behavioral and neuroimaging studies have demonstrated that brain regions involved with speech production also support speech perception, especially under degraded conditions. The premotor cortex (PMC) has been shown to be active during both observation and execution of action ("Mirror System" properties), and may facilitate speech perception by mapping unimodal and multimodal sensory features onto articulatory speech gestures. For this functional magnetic resonance imaging (fMRI) study, participants identified vowels produced by a speaker in audio-visual (saw the speaker's articulating face and heard her voice), visual only (only saw the speaker's articulating face), and audio only (only heard the speaker's voice) conditions with varying audio signal-to-noise ratios in order to determine the regions of the PMC involved with multisensory and modality specific processing of visual speech gestures. The task was designed so that identification could be made with a high level of accuracy from visual only stimuli to control for task difficulty and differences in intelligibility. The results of the functional magnetic resonance imaging (fMRI) analysis for visual only and audio-visual conditions showed overlapping activity in inferior frontal gyrus and PMC. The left ventral inferior premotor cortex (PMvi) showed properties of multimodal (audio-visual) enhancement with a degraded auditory signal. The left inferior parietal lobule and right cerebellum also showed these properties. The left ventral superior and dorsal premotor cortex (PMvs/PMd) did not show this multisensory enhancement effect, but there was greater activity for the visual only over audio-visual conditions in these areas. The results suggest that the inferior regions of the ventral premotor cortex are involved with integrating multisensory information, whereas, more superior and dorsal regions of the PMC are involved with mapping unimodal (in this case visual) sensory features of the speech signal with articulatory speech gestures.

No MeSH data available.


Related in: MedlinePlus

Significant brain activity for the contrast that investigated the multisensory enhancement effect (AV10-A10)-(AV6-A6) thresholded at p < 0.001 uncorrected. Activity was present in left PMvi/Broca's area, left pre- and post-central gyrus, left inferior parietal cortex and suprmarginal gyrus, the right occipital lobe, the right cerebellum lobule VIIb and IX, and the left and right brain stem. (A) Activity rendered on the surface of the left, back, right, and top of the brain. (B) Section through brain taken at MNI coordinate −54, 3, 15 shows activity that was present in the PMvi and Broca's region. (C) Section through brain taken at MNI coordinate 21, −69, −45 shows activity that was present in cerebellum lobule VIIb. L, left side of brain; R, right side of brain.
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Figure 6: Significant brain activity for the contrast that investigated the multisensory enhancement effect (AV10-A10)-(AV6-A6) thresholded at p < 0.001 uncorrected. Activity was present in left PMvi/Broca's area, left pre- and post-central gyrus, left inferior parietal cortex and suprmarginal gyrus, the right occipital lobe, the right cerebellum lobule VIIb and IX, and the left and right brain stem. (A) Activity rendered on the surface of the left, back, right, and top of the brain. (B) Section through brain taken at MNI coordinate −54, 3, 15 shows activity that was present in the PMvi and Broca's region. (C) Section through brain taken at MNI coordinate 21, −69, −45 shows activity that was present in cerebellum lobule VIIb. L, left side of brain; R, right side of brain.

Mentions: Brain regions involved with the audio-visual enhancement effect across different signal-to-noise ratios were investigated using the contrast of (AV10-A10)-(AV6-A6) as well as the contrast of (AV14-A14)-(AV10-A10). The (AV10-A10)-(AV6-A6) contrast shows the degree of audio-visual enhancement as reflected in the behavioral results (see Figure 2) was greater when the signal-to-noise ratio was −10 dB compared to −6 dB. Significant activity was only found in the brain stem using the FDR correction for multiple comparisons, therefore the results are shown using a threshold of p < 0.001 (T = 3.73) uncorrected (see Figure 6). Active brain regions included the left PMvi/Broca's area, left pre-central gyrus (PreCG) Post central gyrus (PostCG), left inferior parietal cortex/supramarginal gyrus (IPC/SMG), right occipital lobe, the right cerebellar lobule VIIb and IX, and the left and right brain stem (see Figure 6 and Table 5). The results of the ROI analysis showed significant activity (p < 0.05 corrected) in the left PMvi/Brocas area (MNI coordinate: −54, 3, 15), and the right cerebellum lobule VIIb (MNI coordinate: 21, −69, −45) (see Table 5). The behavioral results of the interaction of (AV14-A14)-(AV10-A10) did not show a significant multisensory enhancement effect (see Figure 2). Similarly, the results of the fMRI analysis for this contrast also did not reveal any significant activity (p > 0.05 uncorrected).


Multisensory and modality specific processing of visual speech in different regions of the premotor cortex.

Callan DE, Jones JA, Callan A - Front Psychol (2014)

Significant brain activity for the contrast that investigated the multisensory enhancement effect (AV10-A10)-(AV6-A6) thresholded at p < 0.001 uncorrected. Activity was present in left PMvi/Broca's area, left pre- and post-central gyrus, left inferior parietal cortex and suprmarginal gyrus, the right occipital lobe, the right cerebellum lobule VIIb and IX, and the left and right brain stem. (A) Activity rendered on the surface of the left, back, right, and top of the brain. (B) Section through brain taken at MNI coordinate −54, 3, 15 shows activity that was present in the PMvi and Broca's region. (C) Section through brain taken at MNI coordinate 21, −69, −45 shows activity that was present in cerebellum lobule VIIb. L, left side of brain; R, right side of brain.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4017150&req=5

Figure 6: Significant brain activity for the contrast that investigated the multisensory enhancement effect (AV10-A10)-(AV6-A6) thresholded at p < 0.001 uncorrected. Activity was present in left PMvi/Broca's area, left pre- and post-central gyrus, left inferior parietal cortex and suprmarginal gyrus, the right occipital lobe, the right cerebellum lobule VIIb and IX, and the left and right brain stem. (A) Activity rendered on the surface of the left, back, right, and top of the brain. (B) Section through brain taken at MNI coordinate −54, 3, 15 shows activity that was present in the PMvi and Broca's region. (C) Section through brain taken at MNI coordinate 21, −69, −45 shows activity that was present in cerebellum lobule VIIb. L, left side of brain; R, right side of brain.
Mentions: Brain regions involved with the audio-visual enhancement effect across different signal-to-noise ratios were investigated using the contrast of (AV10-A10)-(AV6-A6) as well as the contrast of (AV14-A14)-(AV10-A10). The (AV10-A10)-(AV6-A6) contrast shows the degree of audio-visual enhancement as reflected in the behavioral results (see Figure 2) was greater when the signal-to-noise ratio was −10 dB compared to −6 dB. Significant activity was only found in the brain stem using the FDR correction for multiple comparisons, therefore the results are shown using a threshold of p < 0.001 (T = 3.73) uncorrected (see Figure 6). Active brain regions included the left PMvi/Broca's area, left pre-central gyrus (PreCG) Post central gyrus (PostCG), left inferior parietal cortex/supramarginal gyrus (IPC/SMG), right occipital lobe, the right cerebellar lobule VIIb and IX, and the left and right brain stem (see Figure 6 and Table 5). The results of the ROI analysis showed significant activity (p < 0.05 corrected) in the left PMvi/Brocas area (MNI coordinate: −54, 3, 15), and the right cerebellum lobule VIIb (MNI coordinate: 21, −69, −45) (see Table 5). The behavioral results of the interaction of (AV14-A14)-(AV10-A10) did not show a significant multisensory enhancement effect (see Figure 2). Similarly, the results of the fMRI analysis for this contrast also did not reveal any significant activity (p > 0.05 uncorrected).

Bottom Line: The left inferior parietal lobule and right cerebellum also showed these properties.The left ventral superior and dorsal premotor cortex (PMvs/PMd) did not show this multisensory enhancement effect, but there was greater activity for the visual only over audio-visual conditions in these areas.The results suggest that the inferior regions of the ventral premotor cortex are involved with integrating multisensory information, whereas, more superior and dorsal regions of the PMC are involved with mapping unimodal (in this case visual) sensory features of the speech signal with articulatory speech gestures.

View Article: PubMed Central - PubMed

Affiliation: Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka University Osaka, Japan ; Multisensory Cognition and Computation Laboratory Universal Communication Research Institute, National Institute of Information and Communications Technology Kyoto, Japan.

ABSTRACT
Behavioral and neuroimaging studies have demonstrated that brain regions involved with speech production also support speech perception, especially under degraded conditions. The premotor cortex (PMC) has been shown to be active during both observation and execution of action ("Mirror System" properties), and may facilitate speech perception by mapping unimodal and multimodal sensory features onto articulatory speech gestures. For this functional magnetic resonance imaging (fMRI) study, participants identified vowels produced by a speaker in audio-visual (saw the speaker's articulating face and heard her voice), visual only (only saw the speaker's articulating face), and audio only (only heard the speaker's voice) conditions with varying audio signal-to-noise ratios in order to determine the regions of the PMC involved with multisensory and modality specific processing of visual speech gestures. The task was designed so that identification could be made with a high level of accuracy from visual only stimuli to control for task difficulty and differences in intelligibility. The results of the functional magnetic resonance imaging (fMRI) analysis for visual only and audio-visual conditions showed overlapping activity in inferior frontal gyrus and PMC. The left ventral inferior premotor cortex (PMvi) showed properties of multimodal (audio-visual) enhancement with a degraded auditory signal. The left inferior parietal lobule and right cerebellum also showed these properties. The left ventral superior and dorsal premotor cortex (PMvs/PMd) did not show this multisensory enhancement effect, but there was greater activity for the visual only over audio-visual conditions in these areas. The results suggest that the inferior regions of the ventral premotor cortex are involved with integrating multisensory information, whereas, more superior and dorsal regions of the PMC are involved with mapping unimodal (in this case visual) sensory features of the speech signal with articulatory speech gestures.

No MeSH data available.


Related in: MedlinePlus