Changing meaning causes coupling changes within higher levels of the cortical hierarchy

Abstract

Processing of speech and nonspeech sounds occurs bilaterally within primary auditory cortex and surrounding regions of the superior temporal gyrus; however, the manner in which these regions interact during speech and nonspeech processing is not well understood. Here, we investigate the underlying neuronal architecture of the auditory system with magnetoencephalography and a mismatch paradigm. We used a spoken word as a repeating ''standard'' and periodically introduced 3 ''oddball'' stimuli that differed in the frequency spectrum of the word's vowel. The closest deviant was perceived as the same vowel as the standard, whereas the other 2 deviants were perceived as belonging to different vowel categories. The neuronal responses to these vowel stimuli were compared with responses elicited by perceptually matched tone stimuli under the same paradigm. For both speech and tones, deviant stimuli induced coupling changes within the same bilateral temporal lobe system. However, vowel oddball effects increased coupling within the left posterior superior temporal gyrus, whereas perceptually equivalent nonspeech oddball effects increased coupling within the right primary auditory cortex. Thus, we show a dissociation in neuronal interactions, occurring at both different hierarchal levels of the auditory system (superior temporal versus primary auditory cortex) and in different hemispheres (left versus right). This hierarchical specificity depends on whether auditory stimuli are embedded in a perceptual context (i.e., a word). Furthermore, our lateralization results suggest left hemisphere specificity for the processing of phonological stimuli, regardless of their elemental (i.e., spectrotemporal) characteristics. dynamic causal modeling ͉ language ͉ magnetoencephalography ͉ mismatch negativity ͉ predictive coding

Localization of sublexical speech perception components

“…As discussed above, phonetic and phonological processes are clearly left lateralized in the mid-posterior STS, and we found no evidence for any consistent phonetic activity in the right temporal lobe in Phonetic/Phonological Analysis 1 . As discussed below, the results of Meta-analysis 2 in the present study, and prior electrophysiological evidence also support left hemisphere dominance for some aspects of categorical phoneme perception (Dehaene-Lambertz, 1997; Naatenen et al, 1997; Schofield et al, 2009). …”

Phonological universals constrain the processing of nonspeech stimuli

“…For example, sine-wave speech analogues that are initially perceived as nonspeech by listeners are perceptually less cohesive than synthetic speech (Remez, Pardo, Piorkowski, & Rubin, 2001), and are less likely to elicit categorical perception (Mattingly, Liberman, Syrdal, & Halwes, 1971); audiovisual integration (Kuhl & Meltzoff, 1982;Tuomainen, Andersen, Tiippana, & Sams, 2005) and to engage language regions in the brain (e.g., Scott, Blank, Rosen, & Wise, 2000;Schofield et al, 2009;Vouloumanos, Kiehl, Werker, & Liddle, 2001). Nonetheless, after minimal experience, such nonspeech stimuli can give rise to phonetic processing (e.g., trading relations, Best, Morrongiello, & Robson, 1981), allowing for the identification of linguistic messages (Remez, Rubin, Pisoni, & Carrell, 1981;Remez, Rubin, Berns, Pardo, & Lang, 1994;Remez et al, 2001), and engaging phonetic brain networks (Liebenthal, Binder, Piorkowski, & Remez, 2003;Meyer et al, 2005).…”

Mapping Critical Language Sites in Children Performing Verb Generation: Whole-Brain Connectivity and Graph Theoretical Analysis in MEG

“…More recently, researchers have begun to use sophisticated analytic strategies such as functional and effective connectivity analysis to explore regional interactions for language (Bitan et al, 2005, 2006; Sonty et al, 2007; Allen et al, 2008; Leff et al, 2008; Schofield et al, 2009; David et al, 2011; Doesburg et al, 2012, 2015; Verly et al, 2014; Kadis et al, 2015; Xiao et al, 2016). In our recent MEG study of verb generation in children, we observed frequency dependent patterns of connectivity together with an increased number of suprathreshold effective (directed) connections with age, even though the extent of the network decreased and became increasingly left lateralized with age (Kadis et al, 2015).…”

“…In our recent MEG study of verb generation in children, we observed frequency dependent patterns of connectivity together with an increased number of suprathreshold effective (directed) connections with age, even though the extent of the network decreased and became increasingly left lateralized with age (Kadis et al, 2015). Others have used dynamic causal modeling (DCM) in fMRI to show that higher level language processing is relatively left lateralized, compared to basic sensory processes (Bitan et al, 2005, 2006; Sonty et al, 2007; Allen et al, 2008; Cao et al, 2008; Leff et al, 2008; Schofield et al, 2009; Xiao et al, 2016). In addition, involvement of subcortical structures in language processing has been supported by DCM for MEG and fMRI data related to auditory comprehension task (Booth et al, 2007; David et al, 2011).…”