Changes in functional connectivity within the fronto-temporal brain network induced by regular and irregular Russian verb production

Abstract

Functional connectivity between brain areas involved in the processing of complex language forms remains largely unexplored. Contributing to the debate about neural mechanisms underlying regular and irregular inflectional morphology processing in the mental lexicon, we conducted an fMRI experiment in which participants generated forms from different types of Russian verbs and nouns as well as from nonce stimuli. The data were subjected to a whole brain voxel-wise analysis of context dependent changes in functional connectivity [the so-called psychophysiological interaction (PPI) analysis]. Unlike previously reported subtractive results that reveal functional segregation between brain areas, PPI provides complementary information showing how these areas are functionally integrated in a particular task. To date, PPI evidence on inflectional morphology has been scarce and only available for inflectionally impoverished English verbs in a same-different judgment task. Using PPI here in conjunction with a production task in an inflectionally rich language, we found that functional connectivity between the left inferior frontal gyrus (LIFG) and bilateral superior temporal gyri (STG) was significantly greater for regular real verbs than for irregular ones. Furthermore, we observed a significant positive covariance between the number of mistakes in irregular real verb trials and the increase in functional connectivity between the LIFG and the right anterior cingulate cortex in these trails, as compared to regular ones. Our results therefore allow for dissociation between regularity and processing difficulty effects. These results, on the one hand, shed new light on the functional interplay within the LIFG-bilateral STG language-related network and, on the other hand, call for partial reconsideration of some of the previous findings while stressing the role of functional temporo-frontal connectivity in complex morphological processes.

Brain substrates underlying auditory speech priming in healthy listeners and listeners with schizophrenia

“…The reduced strength of functional connectivity between the STG, MTG, putamen, TriIFG, IPL, precentral cortex and SMA may also account for the declined speech recognition under speech-masking conditions in listeners with schizophrenia. Indeed, previous studies have shown that functional connectivity between these brain regions is not only involved in auditory and/or speech processing (Jeong et al 2009; Mhuircheartaigh et al 2010; Price, 2010; Turken & Dronkers, 2011; Sundermann & Pfleiderer, 2012; Zhang & Li, 2014; Kireev et al 2015; Munoz-Lopez et al 2015) but also impaired in people with schizophrenia (Ford et al 2002; Liu et al 2012; Leroux et al 2014; Pu et al 2014; Zhang & Li, 2014). Moreover, this study reveals that the strength of functional connectivity between the left STG and left TriIFG is significantly correlated with the speech-recognition performance under the informational masking condition in both healthy listeners and listeners with schizophrenia, and reduces in listeners with schizophrenia.…”

Functional connectivity in the developing language network in 4‐year‐old children predicts future reading ability

“…Standard GLM analysis can reveal functionally segregated brain areas that change their activity in response to task conditions (e.g., listening to words or pseudowords, or baseline condition consisting of fixation). On the other hand, PPI is a measure of functional connectivity that provides complementary information about how these brain areas are functionally integrated (Friston, 2011; O'Reilly et al, 2012), and has been applied to study language processing (Kireev et al, 2015; La et al, 2016), and recently with fNIRS data (Hirsch et al, 2017). PPI does not permit inferences about casual relations between activation in separate brain regions, but rather PPI can test the interactions between different brain regions during language processing in different psychological conditions (i.e., task—words, pseudowords; rest).…”

From archebiosis to evolution of organisms and informational systems

“…Efforts to simulate the functions of fossil anthropoid species' sound-producing apparatus and the sounds that could be articulated by this apparatus provides one realm of methodological overlap, as are efforts to reconstruct the cognitive capacities of our hominid ancestors based on neurological predictions and extrapolations from comparative data. Valuable information on this topic is to be found in the studies of linguistic functions as related to cerebral mechanisms (Bichakjian, 1991;Chernigovskaya, 1994;Gor and Chernigovskaya, 2004;Lieberman, 2013).…”

“…Amazingly, these battles are still active in another domain. Compare nativists' views with those of functionalists on language origins and its specific features and the seemingly never-ending discussions of phenomenal mind and qualia (Pinker, 1994;Chomsky, 2000;Deacon, 2003Deacon, , 2004Deacon, , 2013Jackendoff, 2003Jackendoff, -2004Chernigovskaya, 2004Chernigovskaya, , 2007Chernigovskaya, , 2013Friederici, 2011Friederici, , 2017Chomsky and McGilvray, 2012;Slioussar et al, 2014;Kireev et al, 2015). So the debate continues in spite of all the new methods and technologies that have become available to explore these questions.…”