Network Dynamics of Broca's Area During Word Selection

PLoS One. 2019 Dec 20;14(12):e0225756. doi: 10.1371/journal.pone.0225756. eCollection 2019.

Abstract

Current models of word-production in Broca's area (i.e. left ventro-lateral prefrontal cortex, VLPFC) posit that sequential and staggered semantic, lexical, phonological and articulatory processes precede articulation. Using millisecond-resolution intra-cranial recordings, we evaluated spatiotemporal dynamics and high frequency functional interconnectivity between left VLPFC regions during single-word production. Through the systematic variation of retrieval, selection, and phonological loads, we identified specific activation profiles and functional coupling patterns between these regions that fit within current psycholinguistic theories of word production. However, network interactions underpinning these processes activate in parallel (not sequentially), while the processes themselves are indexed by specific changes in network state. We found evidence that suggests that pars orbitalis is coupled with pars triangularis during lexical retrieval, while lexical selection is terminated via coupled activity with M1 at articulation onset. Taken together, this work reveals that speech production relies on very specific inter-regional couplings in rapid sequence in the language dominant hemisphere.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acoustic Stimulation
  • Adult
  • Broca Area / physiology*
  • Female
  • Gamma Rhythm / physiology
  • Humans
  • Language
  • Male
  • Nerve Net / physiology*
  • Reaction Time
  • Speech / physiology
  • Vocabulary*

Grant support

Funded by National Science Foundation (NSF): Nitin Tandon 1533664. National Institutes of Health (NIH): Nitin Tandon DC014589. National Institutes of Health (NIH): Nitin Tandon NS098981. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.