Perceptual Systems Controlling Speech Production

Abstract

It is proposed that the acquisition and maintenance of fluent speech depend on the rapid temporal integration of motor feedforward and polysensory (auditory and somatosensory) feedback signals. In a functional magnetic resonance imaging study on 21 healthy righthanded, English-speaking volunteers, we investigated activity within these motor and sensory pathways and their integration during speech. Four motor conditions were studied: two speech conditions (propositional and nonpropositional speech) and two silent conditions requiring repetitive movement of the principal articulators (jaw and tongue movements). The scanning technique was adapted to minimize artifact associated with overt speech production. Our result indicates that this multimodal convergence occurs within the left and right supratemporal planes (STPs), with peaks of activity at their posteromedial extents, in regions classically considered as unimodal auditory association cortex. This cortical specialization contrasted sharply with the response of somatosensory association cortex (SII), in which activity was suppressed during speech but not during the silent repetitive movement of the principal articulators. It was also clearly distinct from the response of lateral auditory association cortex, which responded to auditory feedback alone, and from that within a left lateralized ventrolateral temporal and inferior frontal system, which served lexical-and sentence-level language retrieval. This response of cortical regions related to speech production is not predicted by the classical model of hierarchical cortical processing, providing new insights into the role of the STP in polysensory integration and into the modulation of activity in SII during normal speech production. These findings have novel implications for the acquisition and maintenance of fluent speech.

An examination of the rapid automatized naming–reading relationship using functional magnetic resonance imaging

“…First, our results provided evidence that RAN and reading activate similar brain regions, including areas such as the posterior MTG (semantic access; Graves et al,, 2010;Onitsuka et al, 2004;Rapcszk & Beeson, 2004;Vandenberghe, Price, Wise, Josephs, & Frackowiak, 1996;Whitney, Kirk, O'Sullivan, Ralph, & Jefferies, Cummine 22 2010), SMG (grapheme-phoneme mapping and somatosensory maps; Paulesu, Frith, & Frackowiak, 1993;Stoeckel, Gough, Watkins, & Devlin, 2009), motor and cerebellar cortex (timing and initiating motor output; He et al, 2013), SMA cortex (articulation; Alario, Chainay, Lehericy, & Cohen, 2006;Brown et al, 2009), and anterior cingulate (speech monitoring; Barch, Braver, Saab, & Noll, 2000;Chang, Kenney, Loucks, Poletto, & Ludlow, 2009;Christoffels, Formisano, & Schiller, 2007;Guenther & Vladusich, 2012;Price, 2012). Second, our results showed that RAN and reading are differentially activating regions associated with orthographic (inferior temporal gyrus; Bruno, Zumberge, Manis, Lu, & Goldman, 2008) and phonological (supramarginal gyrus, superior temporal gyrus; Dhanjal, Handunnetthi, Patel, & Wise, 2008) processing, but not articulatory/motor processing (cerebellum, supplementary motor area, precentral gyrus; Dhanjal et al, 2008), with respect to the magnitude of activation (i.e., PSC). In addition, we found direct functional neuroanatomical evidence that multiple RAN-reading neural associations exist and these associations reside predominantly within shared articulatory/motor/sequencing regions, including cerebellum, supplementary motor area and precentral gyrus.…”

Phoneme and word recognition in the auditory ventral stream

“…Whereas ventral networks are implicated in pattern recognition, dorsal networks are implicated in forward-and inverse-model computation (42,44), including sensorimotor integration (42,45,48,134). This supports a role for left dorsal networks in mapping auditory representations onto the somatomotor frame of reference (135)(136)(137)(138)(139), yielding articulator-encoded speech. This ventral-dorsal dissociation is illustrated in an experiment by Buchsbaum and colleagues (2005) (110).…”

Regional variation, hemispheric asymmetries and gender differences in pericortical white matter

“…Statistical significance of repeated measures ANOVA. speech sounds requires the analysis of rapid temporal transients that distinguish different phonemes (Lieberman, 2002) and speech production depends upon the precise temporal coordination of phonological processing regions in auditory cortex and motor speech centers in the inferior frontal lobe (Dhanjal et al, 2008). Similarly, multimodal sensory integration depends on the accurate timing of auditory and visual inputs in the posterior temporal lobe (Hein and Knight, 2008), and the analysis of visual motion in middle temporal regions requires the temporally precise analysis of visual inputs (Martinez-Trujillo et al, 2005).…”