Neural Representations and Mechanisms for the Performance of Simple Speech Sequences

“Such multiplicative or shunting terms (Grossberg, 1973) are motivated by empirically observed cell membrane properties (e.g., Hodgkin & Huxley, 1952).”

“More recent neural network models (Beiser & Houk, 1998; Elman, 1990; Lewandowsky & Murdock, 1989; Jordan, 1986) proposed revisions that rely”

“The organization of BG circuits into largely parallel loops (Alexander & Crutcher, 1990; Alexander et al., 1986) offers one possible substrate for the cascaded processing stages that enable linguistic selections from competing alternatives; these selections (cf. choice layer activations) can then…”

“These properties help explain why there is a low limit (see Cowan, 2000) to the number of items that can be planned in working memory and recalled in the correct order.”

“SSM representations are functionally similar to a mental syllabary (Levelt & Wheeldon, 1994; Crompton, 1982), suggested by Levelt et al. (1999) to consist of a “repository of gestural scores for the frequently used syllables of the language” (p. 5).”

“Such models generally follow the theoretical work of Levelt ( 1989 ), Garrett ( 1975 ), and others.”

“Interactions between the cortex and the BG are organized into multiple loop circuits (Middleton & Strick, 2000; Alexander & Crutcher, 1990; Alexander, DeLong, & Strick, 1986).”

“Finally, the left putamen and thalamus were incorporated into a motor loop that passes activity from the SMA via the putamen to the thalamus and into the motor cortex (Bohland et al., 2010).”

“Parallel to the unfolding of this information, a feedback control subsystem corrects for perceived deviations of the preplanned movements from their predicted goals [55, 56].”

“Further levels (and so other competitive queuing networks) are needed for actual production and to account for speech errors (see Bohland et al., 2009 for details).”

“All simulations assume that the motor programs for the ''go'', ''di'', and ''vE'' syllables were among those acquired by the DIVA portion of the circuit (see Bohland et al., 2010).”

“Using a neurobiologically plausible model of speech production (Guenther et al., 2006; Bohland et al., 2010), the authors tested the hypothesis that an excess in dopamine would cause overexcitation of the thalamus, in effect disrupting the basal ganglia input to the ventral premotor cortex.”

“basal ganglia critically support the initiation of speech sequence production (Bohland et al., 2010), while the cerebellum interfaces between cortical motor and sensory areas via the thalamus to play a role in speech error correction when there is a mismatch between the expected and actual self-initiated sensory (audi…”

“…Mapping hypothesized based on imaging studies (e.g., Ghosh et al., 2008; Tourville et al., 2008). t1:15 Tongue 1 (−60.2, −2.8, 27) (62.9, −1.5, 28.9) Mapping hypothesized based on Boling et al. (2002) and supported by somatosensory evoked potential study of humans (McCarthy et al., 1993). t1:16…”

“In the current review, we will utilize the Directions Into Velocities of Articulators (DIVA) neurocomputational modeling framework (Guenther et al., 2006; Bohland et al., 2010; Guenther, 2016) to mechanistically interpret relevant findings from the behavioral and neurological literatures on developmental stuttering.”

“More recent mechanistic network models have integrated the selection and learning mechanisms into a single model including the direct, indirect and hyperdirect pathways of the BG, with different model neurons to simulate physiological properties of the different nuclei [13,12,22].”

“…provide feed- forward information during speech production—the supramarginal gyrus involves somatosensory targets and the superior temporal gyrus and superior temporal sulcus provide auditory targets for speech articulation (Guenther et al., 1998; Bohland et al., 2010; Golfinopolous et al., 2010).”

“The integration of the DIVA model with the GODIVA model [75], a neurocomputational model of the sequencing of syllables in multisyllabic utterances, holds potential for filling this gap and for establishing an appropriate framework for investigating relations between the deficits of auditory-motor interaction and the…”

“The directions into velocities of articulators (DIVA) model articulators including the upper and lower lips,the jaw,the tongue, and the larynx.”

“Interestingly, it seems that SMA operates initiation of planned speech actions [66].”

“A speech production model maps the processing of feedback control to fronto-parietal and frontotemporal networks (Guenther et al., 1998; Bohland et al., 2009).”

“Benke et al. (2000) proposed that repetitive speech phenomena in PD patients can be divided into two types, the first resembling palilalia (with hyperfluent repetitions, fast utterances, increased speech rate and often blurred or murmured due to articulation that is poor or decreasing in loudness)…”

“…of non-speech motor sequence learning studies (Hikosaka et al., 1996; Lehericy et al., 2005; Poldrack et al., 2005), and we have previously proposed that this network interacts with the premotor cortex to sequentially execute a series of speech motor programs (Bohland, Bullock, & Guenther, 2010).”

“, 2009), internally generated phonological representation (Bohland et al., 2010; Hickok, 2012; Rauschecker, 2012; Tian and Poeppel, 2013) and semantic representation (Binder et al.”

“This finding was consistent with the critical role played by the left vPMC in the DIVA model of speech motor control (Guenther et al., 2006; Golfinopoulos et al., 2010) and the GODIVA model of speech sequencing (Bohland et al., 2010).”

“…mechanism akin to internal feedback that serves the purpose of regulating when plans are deselected, such as a “ deactivation time ” parameter (Rumelhart & Norman, 1982), “ postselection negative feedback ” (Dell, 1986), or a “ a non-speci fi c response suppression signal ” (Bohland et al., 2010).”

“(2002), who taught non-human primates to copy geometrical shapes presented on the computer screen while they recorded multi-unit activity from the prefrontal cortex, an area homologous to the inferior frontal cortex in the human brain (Bohland et al., 2010).”

“The results are inconsistent with the hypothesis that sensorimotor adaptation in speech occurs by altering a global predictive model that is shared by the production control machinery for different movements (Houde and Jordan, 2002; Villacorta et al., 2007; Bohland et al., 2010).”

“The earlier more rostral peak in PTr and left insular cortex, synchronous with SMA activation, corresponds to the longer reaction time for four-syllable trials and could reflect the more complicated action selection required for framing and ordering the four-syllable utterance; the later more caudal load effect in POs…”

“An uncoupling of motor output cells from motor plan cells would allow the system to prepare subsequent sensorimotor programs while a former program is executed (Bohland et al., 2010).”

“…planning components have not been the focus of the current review, some of the models (notably DIVA and TD) also include computational implementations of the planner (Bohland et al. , 2010; Saltzman et al. , 2008) that operates between the higher-level linguistic processes and the controller (Fig.”

“This notion is supported by theories and models postulating left area 44 to be one of the core cortical hubs in the network of speechplanning-related operations (Bohland et al., 2009; Flinker et al., 2015; Guenther and Hickok, 2015).”

“Given the current interest in understanding motor planning (e.g. pre-motor, motor, monitoring, etc.) in the context of language production (for speech, see e.g., Bohland, Bullock, & Guenther, 2010; Hickok, 2014), such a separation seems no longer tenable.”

“The authors proposed that AWS lack sufficient sensorymotor planning of speech gestures in a region of the motor cortex that is a key player in establishing such programs (Bohland et al., 2010; Guenther and Vladusich, 2012; Neef et al., 2015).”

“, 2011); 3) identified as an input region that receives cortical efference copies of motor planning from the motor cortex that allows timely initiation and termination of speech sound sequences, posited to be deficient in a neuro-computational model of stuttering (Bohland et al., 2010; Civier et al., 2013).”

“To address the higher-level mechanisms involved in bu ff ering and sequencing through longer speech utterances, we developed the GODIVA model in 2010 (Bohland et al., 2010).”

“The integrity of these subcortical networks seems to be essential for the smooth activities of basal speech motor programs ensuring timely, rapid and coordinated movements (e.g. Wildgruber et al. 2001; Bohland et al. 2010).”

“computational processes involved in sequencing articulator movements, which form a requisite mechanism of speech production (Guenther 2006; Bohland et al. 2010; Cogan et al. 2014; Simmonds et al. 2014).”

“, 2020), has further motivated finergrained distinctions in the function of this tract into mapping phonological codes onto abstract motor plans (Bohland et al., 2010; Miller and Guenther, 2021) vs.”

“It is almost certainly the case that higher-order brain areas (e.g., Broca’s area, supplementary motor area) contain more invariant representations than those found here for vSMC (Bohland and Guenther, 2006; Bohland et al., 2010).”

“The SSM cells represent speech sounds (which may range in size from phonemes to syllables to frequent words and phrases) and are presumed to be activated by higher level input from the phonological encoding stage (Bohland, Bullock, & Guenther, 2010; Guenther et al., 2006).”

“Some CQmodels have incorporated rank information (Bohland et al., 2010; Bradski et al., 1994).”

“The caudate is part of the basal ganglia, a group of subcortical regions theorized to be crucial for sequencing and timing in speech production (Bohland et al., 2010; Fridriksson et al., 2005; Guenther, 2006; Lu et al., 2010a, 2010b; Pickett et al., 1998; Stahl et al., 2011), while the left IFG and cingulate cortex ar…”

“…in many motor and non-motor systems, with different regions being involved in time coding (Mita et al., 2009) and temporal processing (Kotz and Schwartze, 2011), sequencing(Sohn and Lee, 2007), gating (Bohland et al., 2010), and so on, culminating in successful “motor planning” (Li et al., 2016).”

“These findings also can be interpreted in the context of the GODIVA model (Bohland et al., 2010) of speech production.”

“Some Item-and-Order models incorpo536 rated rank information (e.g., Bohland et al., 2010; Bradski 537 et al., 1994).”

“There are several extant speech production models, each developed to accomplish different goals (see, for example 51 – 55 ).”

“…through the modulation of cellular-level changes, including sodium and calcium-dependent channels and NMDA receptor activity, thereby promoting long-term potentiation/depression (LTP/LTD) like effects (Stagg et al., 2009; Fritsch et al., 2010; Bolognini et al., 2011; Stagg and Nitsche, 2011).”

“Among models of speech motor control, only state feedback control models (Houde and Nagarajan, 2011) (Bohland et al., 2010) devote significant attention to the function of basal ganglia-thalamocortical loops.”

“Importantly, the goals remain nonoverlapping even in high-frequency combinations when, through repeated practice, they may be stored together as part of a larger chunk (see, e.g., Bohland et al., 2010, p. 1505).”

“The GODIVA (Gradient Order Directions Into Velocities of Articulators) model, an extension of the DIVA model (Guenther, 2006) provides an explanation on how speech movements are selected, sequenced and initiated (Bohland et al., 2010).”

“Two of these models that have paid some attention to this issue, however, are the GODIVA model (Bohland et al., 2009) and the WEAVERþþ model (Levelt et al., 1999).”

“A number of models with a similar activation-dependent selection mechanism have been developed [6,43,44].”

“Speech imitation is a complex and multistage process that requires the interaction of both sensory and motor systems, such that acoustic inputs can be processed, transformed to target motor outputs, and articulated as speech (see Guenther 2006; Bohland et al. 2010; Guenther and Vladusich 2012).”

“In the GODIVA model [1], segments organize speech movements and segments are competitively selected to fill syllable positions, which may in turn influence parameters relating to the control of articulation.”

“, the Gradient Order DIVA (GODIVA) model (77, 78), which includes both feed-forward and feedback processes.”

“In most models of speech production, the contrasting activation between competing motor plans results primarily from linguistic and/or speech motor parameters exclusively within the speech production system (e.g. Bohland et al., 2010; Guenther et al., 2006; Roelofs, 1997).”

“, 2018) and may play a role in many motor and non-motor tasks controlling sequencing (Sohn and Lee, 2007), gating (Bohland et al., 2010) and motor planning (Li et al.”

“Several neurobiological and computational models assume that the syllable is a basic sublexical unit for speech processing and production (e.g., Bohland et al., 2010; Guenther & Vladusich, 2012; Guenther et al., 2006; Levelt, 1999; MacNeilage, 1998).”

“After Grossberg (1978a, 1978b) introduced the Item-and-Order model, it was used in various forms in a number of other studies (e.g. Boardman and Bullock, 1991; Bohland et al., 2010; Bradski et al., 1994; Bullock and Rhodes, 2003; Grossberg and Pearson, 2008; Houghton, 1990; Page and Norris, 1998).”

“The GODIVA model [10] posits the existence of parallel phonological output buffers in the left inferior frontal sulcus (IFs) and pre-supplementary motor area (pre-SMA), with the left IFs serving to encode phonemic sequences and the pre-SMA representing abstract syllable frames [see also 72].”

“Instead, this perturbation is more likely to disrupt the proper generation of timing cues by the basal ganglia as outlined in the GODIVA account (Bohland et al., 2010); that is, since audi-”