Format

Send to

Choose Destination
Hum Brain Mapp. 2014 Nov;35(11):5587-605. doi: 10.1002/hbm.22572. Epub 2014 Jul 4.

An ALE meta-analysis on the audiovisual integration of speech signals.

Author information

1
Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia; Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia.

Abstract

The brain improves speech processing through the integration of audiovisual (AV) signals. Situations involving AV speech integration may be crudely dichotomized into those where auditory and visual inputs contain (1) equivalent, complementary signals (validating AV speech) or (2) inconsistent, different signals (conflicting AV speech). This simple framework may allow the systematic examination of broad commonalities and differences between AV neural processes engaged by various experimental paradigms frequently used to study AV speech integration. We conducted an activation likelihood estimation metaanalysis of 22 functional imaging studies comprising 33 experiments, 311 subjects, and 347 foci examining "conflicting" versus "validating" AV speech. Experimental paradigms included content congruency, timing synchrony, and perceptual measures, such as the McGurk effect or synchrony judgments, across AV speech stimulus types (sublexical to sentence). Colocalization of conflicting AV speech experiments revealed consistency across at least two contrast types (e.g., synchrony and congruency) in a network of dorsal stream regions in the frontal, parietal, and temporal lobes. There was consistency across all contrast types (synchrony, congruency, and percept) in the bilateral posterior superior/middle temporal cortex. Although fewer studies were available, validating AV speech experiments were localized to other regions, such as ventral stream visual areas in the occipital and inferior temporal cortex. These results suggest that while equivalent, complementary AV speech signals may evoke activity in regions related to the corroboration of sensory input, conflicting AV speech signals recruit widespread dorsal stream areas likely involved in the resolution of conflicting sensory signals.

KEYWORDS:

activation likelihood estimation; asynchronous; auditory dorsal stream; cross-modal; language; incongruent; inferior frontal gyrus; multisensory; superior temporal sulcus

PMID:
24996043
PMCID:
PMC4206592
DOI:
10.1002/hbm.22572
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center