Conflict monitoring in speech processing: An fMRI study of error detection in speech production and perception

Abstract

26To minimize the number of errors in speech, and thereby facilitate 27 communication, speech is monitored before articulation. It is, however, unclear at 28 which level during speech production monitoring takes place, and what mechanisms 29 are used to detect and correct errors. The present study investigated whether 30 internal verbal monitoring takes place through the speech perception system, as 31proposed by perception--based theories of speech monitoring, or whether 32 mechanisms independent of perception are applied, as proposed by production--33 based theories of speech monitoring. With the use of fMRI during a tongue twister 34 task we observed that error detection in internal speech during noise--masked overt 35 speech production and error detection in speech perception both recruit the same 36 neural network, which includes pre--supplementary motor area (pre--SMA), dorsal 37 anterior cingulate cortex (dACC), anterior insula (AI), and inferior frontal gyrus (IFG). 38Although production and perception recruit similar areas, as proposed by 39 perception--based accounts, we did not find activation in superior temporal areas 40 (which are typically associated with speech perception) during internal speech 41 monitoring in speech production as hypothesized by these accounts. On the 42 contrary, results are highly compatible with a domain general approach to speech 43 monitoring, by which internal speech monitoring takes place through detection of 44 conflict between response options, which is subsequently resolved by a domain 45 general executive center (e.g., the ACC). 46 47 3

Grammatical constraints on language switching: Language control is not just executive control

“…Thus, we conclude that language specific control mechanisms remain relatively intact and unchanged in aging bilinguals, and that the main effect of aging (especially the increased rate of intrusion errors which can not simply be attributed to age-related slowing), should be attributed to decline in executive control ability, and a role this plays in monitoring upcoming speech after it is planned (Gauvin, De Baene, Brass, & Hartsuiker, 2016; Nozari, Dell, & Schwartz, 2011; Postma, 2000). On this view, relatively automatic aspects of language control remain intact in aging (e.g., grammatical encoding and the propensity to allow language switches in some, perhaps cross-linguistically more syntactically congruous contexts, and for some parts of speech, more than others).…”

“…One notable exception in this regard was older bilinguals’ lower rate of self-corrections of intrusion errors (i.e., rate of partial relative to full intrusion errors; see Figure 6). This result led us to suggest that executive control ability may play an important role in monitoring upcoming speech after it is planned (see Discussion section in Experiment 2; Gauvin et al, 2016; Nozari et al, 2011). Also of particular interest here was the absence of an interaction between aging and language dominance on within-language errors; both aging effects and dominance effects were highly robust in Experiment 2, but we obtained no evidence that older bilinguals had particular difficulty controlling speech in a less proficient language.…”

Subjective experience of inner speech in aphasia: Preliminary behavioral relationships and neural correlates

“…In this case, severe verbal apraxia and lesions in the ventral motor and premotor areas would be expected to result in less sIS, not more, as we found in our analyses. Another recent functional imaging study on unimpaired participants found monitoring of both inner and aloud speech was associated with increased activation in a domain-general error detection area, the ACC, as well as the posterior IFG (Gauvin, De Baene, Brass, & Hartsuiker, 2015). These results suggest that lesions in the posterior IFG might cause unreliable self-monitoring, not a relationship with frequency of sIS as we found.…”

Roles of Supplementary Motor Areas in Auditory Processing and Auditory Imagery

“…For speech perception, functional neuroimaging studies have reported activity in response to syllables 50, 51, words 52, 53, and sentences 54, 55, 56, 57, 58, 59. Such responses seem to be modulated by the difficulty of speech processing and comprehension.…”