Abstract
The temporal synchrony of auditory and visual signals is known to affect the perception of an external event, yet it is unclear what neural mechanisms underlie the influence of temporal synchrony on perception. Using parametrically varied levels of stimulus asynchrony in combination with BOLD fMRI, we identified two anatomically distinct subregions of multisensory superior temporal cortex (mSTC) that showed qualitatively distinct BOLD activation patterns. A synchrony-defined subregion of mSTC (synchronous > asynchronous) responded only when auditory and visual stimuli were synchronous, whereas a bimodal subregion of mSTC (auditory > baseline and visual > baseline) showed significant activation to all presentations, but showed monotonically increasing activation with increasing levels of asynchrony. The presence of two distinct activation patterns suggests that the two subregions of mSTC may rely on different neural mechanisms to integrate audiovisual sensory signals. An additional whole-brain analysis revealed a network of regions responding more with synchronous than asynchronous speech, including right mSTC, and bilateral superior colliculus, fusiform gyrus, lateral occipital cortex, and extrastriate visual cortex. The spatial location of individual mSTC ROIs was much more variable in the left than right hemisphere, suggesting that individual differences may contribute to the right lateralization of mSTC in a group SPM. These findings suggest that bilateral mSTC is composed of distinct multisensory subregions that integrate audiovisual speech signals through qualitatively different mechanisms, and may be differentially sensitive to stimulus properties including, but not limited to, temporal synchrony.
| Original language | English |
|---|---|
| Pages (from-to) | 3308-3318 |
| Number of pages | 11 |
| Journal | NeuroImage |
| Volume | 49 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 15 2010 |
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Keywords
- fMRI
- Integration
- Multisensory
- STS
- Superior colliculus
- Synchrony
ASJC Scopus subject areas
- Cognitive Neuroscience
- Neurology
Cite this
Neural processing of asynchronous audiovisual speech perception. / Stevenson, Ryan A.; Altieri, Nicholas A.; Kim, Sunah; Pisoni, David; James, Thomas W.
In: NeuroImage, Vol. 49, No. 4, 15.02.2010, p. 3308-3318.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Neural processing of asynchronous audiovisual speech perception
AU - Stevenson, Ryan A.
AU - Altieri, Nicholas A.
AU - Kim, Sunah
AU - Pisoni, David
AU - James, Thomas W.
PY - 2010/2/15
Y1 - 2010/2/15
N2 - The temporal synchrony of auditory and visual signals is known to affect the perception of an external event, yet it is unclear what neural mechanisms underlie the influence of temporal synchrony on perception. Using parametrically varied levels of stimulus asynchrony in combination with BOLD fMRI, we identified two anatomically distinct subregions of multisensory superior temporal cortex (mSTC) that showed qualitatively distinct BOLD activation patterns. A synchrony-defined subregion of mSTC (synchronous > asynchronous) responded only when auditory and visual stimuli were synchronous, whereas a bimodal subregion of mSTC (auditory > baseline and visual > baseline) showed significant activation to all presentations, but showed monotonically increasing activation with increasing levels of asynchrony. The presence of two distinct activation patterns suggests that the two subregions of mSTC may rely on different neural mechanisms to integrate audiovisual sensory signals. An additional whole-brain analysis revealed a network of regions responding more with synchronous than asynchronous speech, including right mSTC, and bilateral superior colliculus, fusiform gyrus, lateral occipital cortex, and extrastriate visual cortex. The spatial location of individual mSTC ROIs was much more variable in the left than right hemisphere, suggesting that individual differences may contribute to the right lateralization of mSTC in a group SPM. These findings suggest that bilateral mSTC is composed of distinct multisensory subregions that integrate audiovisual speech signals through qualitatively different mechanisms, and may be differentially sensitive to stimulus properties including, but not limited to, temporal synchrony.
AB - The temporal synchrony of auditory and visual signals is known to affect the perception of an external event, yet it is unclear what neural mechanisms underlie the influence of temporal synchrony on perception. Using parametrically varied levels of stimulus asynchrony in combination with BOLD fMRI, we identified two anatomically distinct subregions of multisensory superior temporal cortex (mSTC) that showed qualitatively distinct BOLD activation patterns. A synchrony-defined subregion of mSTC (synchronous > asynchronous) responded only when auditory and visual stimuli were synchronous, whereas a bimodal subregion of mSTC (auditory > baseline and visual > baseline) showed significant activation to all presentations, but showed monotonically increasing activation with increasing levels of asynchrony. The presence of two distinct activation patterns suggests that the two subregions of mSTC may rely on different neural mechanisms to integrate audiovisual sensory signals. An additional whole-brain analysis revealed a network of regions responding more with synchronous than asynchronous speech, including right mSTC, and bilateral superior colliculus, fusiform gyrus, lateral occipital cortex, and extrastriate visual cortex. The spatial location of individual mSTC ROIs was much more variable in the left than right hemisphere, suggesting that individual differences may contribute to the right lateralization of mSTC in a group SPM. These findings suggest that bilateral mSTC is composed of distinct multisensory subregions that integrate audiovisual speech signals through qualitatively different mechanisms, and may be differentially sensitive to stimulus properties including, but not limited to, temporal synchrony.
KW - fMRI
KW - Integration
KW - Multisensory
KW - STS
KW - Superior colliculus
KW - Synchrony
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UR - http://www.scopus.com/inward/citedby.url?scp=73749083278&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2009.12.001
DO - 10.1016/j.neuroimage.2009.12.001
M3 - Article
C2 - 20004723
AN - SCOPUS:73749083278
VL - 49
SP - 3308
EP - 3318
JO - NeuroImage
JF - NeuroImage
SN - 1053-8119
IS - 4
ER -