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).”

“Similarly, Dell (1986) speculated that a principle explanation for the appearance of speech errors in normal speech is the speakerʼs need for productivity or generativity.”

“These recording sites were within approximately 5 mm of the ventral portion of the arcuate sulcus, which has been proposed to be homologous to the IFS in humans (Rizzolatti & Arbib, 1998).”

“Mink (1996) and Mink and Thach (1993) outlined a conceptual model of BG function, suggesting that BG loops are used to selectively enable a motor program for output among competing alternatives.”

“The architecture within BG loops is intricate (eg, Parent & Hazrati, 1995 ), but here we adopt a simplified view to limit the model's overall complexity.”

“The medial frontal cortex, consisting of the more posterior SMA and the more anterior pre-SMA (Picard & Strick, 1996; Matsuzaka, Aizawa, & Tanji, 1992), has been implicated in sequencing and speech production tasks.”

“Learning rules that conserve total synaptic strength have been proposed elsewhere (Grossberg, 1976;von der Malsburg, 1973), and similar conservational principles have been observed empirically (Markram & Tsodyks, 1996).”

“The medial frontal cortex, consisting of the more posterior SMA and the more anterior pre-SMA (Picard & Strick, 1996; Matsuzaka, Aizawa, & Tanji, 1992), has been implicated in sequencing and speech production tasks.”

“A similar region in left dorsal inferior frontal gyrus has been suggested to be involved in sequencing discrete units, including phonemes (Gelfand&Bookheimer, 2003), and in phonological encoding tasks (Papoutsi et al., 2009; Chein & Fiez, 2001; Burton, Small, & Blumstein, 2000; Poldrack et al., 1999).”

“Learning rules that conserve total synaptic strength have been proposed elsewhere (Grossberg, 1976; von der Malsburg, 1973), and similar conservational principles have been observed empirically (Markram & Tsodyks, 1996).”

“Un co rre cte d Pr oo f stereotyped, however, readout by serial or “synfire” chains (e.g., Pulvermüller, 1999, 2002; Abeles, 1991) can offer greater efficiency.”

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

“Such loops may be nested to account for various levels of language production (e.g., Ward, 1994; Garrett, 1975).”

“MacNeilage (1998) has proposed that speech evolved the capability to program syllabic frames with phonological content elements and that every speaker learns to make use of this capacity during his or her own period of speech acquisition.”

“The SSM is a component of the DIVA model (Guenther et al., 1998, 2006; Guenther, 1995) that is hypothesized to contain cells that, when activated, “readout” motor programs and sensory expectations for well-learned speech sounds.”

“Learning rules that conserve total synaptic strength have been proposed elsewhere (Grossberg, 1976; von der Malsburg, 1973), and similar conservational principles have been observed empirically (Markram & Tsodyks, 1996).”

“…but less prevalent (only 2–3% of striatal cells in rats, but perhaps as many as 23% in humans; Graveland, 1985), are heterogeneous interneurons, many of which exhibit resting firing rates and receive cortical, thalamic, and dopaminergic input (Tepper, Koos, & Wilson, 2004; Kawaguchi, 1993).”

“Because total activity growth is a decelerating and saturating function of the number of planned items in a sequence, relative activation levels become more difficult to distinguish, and more readily corrupted by noise (Page & Norris, 1998), in longer sequences.”

“də,” an example of a simple exchange error that obeys syllable position constraints as noted in previous studies (e.g. MacKay, 1970; Shattuck-Hufnagel, 1979).”

“Vousden et al. (2000) presented a similarly motivated model that is derived from a previous proposal for serial recall (Brown et al., 2000).”

“Rank-order-selective cells have also been found, primarily in the pre-SMA, whose activity increased before the nth movement in the sequence, regardless of the particular movement (see also Clower & Alexander, 1998).”

“Recent models within this lineage hypothesize order to be accounted for by some contextual signal such as the state of an oscillatory circuit or other time-varying function (Brown, Preece, &Hulme, 2000; Vousden, Brown,&Harley, 2000; Burgess & Hitch, 1999; Henson, 1998).”

“This input is thresholded by θq, and amplified via a faster-than-linear activation function, y(x) =x2 (Grossberg, 1973).”

“Such action selection models (also Gurney, Prescott, & Redgrave, 2001a , 2001b ; Kropotov & Etlinger, 1999 ; Redgrave, Prescott, & Gurney, 1999 ), which suggest that the BG do not generate movements but rather select and enable them, are relevant for sequence performance.”

“Construction of the model was guided by previous theoretical work as well as clinical and experimen- tal results, most notably a companion fMRI study (Bohland & Guenther, 2006).”

“The WEAVER (and later WEAVER++) model (Levelt et al., 1999; Roelofs, 1997) is broadly a computer implementation of the Nijmegen model.”

“…in which frequently encountered syllables are produced with a shorter latency than uncommon (but well-formed) syllables, has been reported by several researchers (Cholin, Levelt, & Schiller, 2006; Laganaro & Alario, 2006; Alario et al., 2004; Carreiras & Perea, 2004; Levelt & Wheeldon, 1994).”

“Construction of the model was guided by previous theoretical work as well as clinical and experimen- tal results, most notably a companion fMRI study (Bohland & Guenther, 2006).”

“Crinion et al. (2006) have also suggested that the caudate may subserve selection of words from a bilingual lexicon.”

“Importantly, at around 18 months of age, the rate of word acquisition in children may quadruple (Goldfield & Reznick, 1990 ).”

“The left prefrontal cortex, specifically in and surrounding the ventral inferior frontal sulcus (IFS), showed increased activity in a memory-guided speaking task when the serial complexity of the utterance was increased (Bohland & Guenther, 2006).”

“Finally, damage to the SSM or the interface between the IFS choice field and the SSM (e.g., damage to corticocortical projections) should lead to problems in realizing a phonetic plan or diminished ability to choose a phonetic plan; these deficits would be in line with observations in patients with AOS (Hillis et al.,…”

“DIVA is a neural network model of speech motor control and acquisition that offers unified explanations for a large number of speech phenomena including motor equivalence, contextual variability, speaking rate effects, and coarticulation (Guenther et al., 1998; Guenther, 1995).”

“Construction of the model was guided by previous theoretical work as well as clinical and experimen- tal results, most notably a companion fMRI study (Bohland & Guenther, 2006).”

“Also found in the striatum, but less prevalent (only 2–3% of striatal cells in rats, but perhaps as many as 23% in humans; Graveland, 1985), are heterogeneous interneurons, many of which exhibit resting firing rates and receive cortical, thalamic, and dopaminergic input ( Tepper, Koos, & Wilson, 2004; Kawaguchi, 1993).”

“DIVA is a neural network model of speech motor control and acquisition that offers unified explanations for a large number of speech phenomena including motor equivalence, contextual variability, speaking rate effects, and coarticulation (Guenther et al., 1998; Guenther, 1995).”

“, 2000), and both structural and functional abnormalities have been observed in the caudate in patients with inherited verbal dyspraxia characterized by particular difficulties with complex speech sequences (Vargha-Khadem et al., 1998; Watkins et al., 2002).”

“…are based on integrating the sparse available data from clinical and functional imaging studies and from inferences drawn from nonspeech sequencing tasks in other species, under the assumption that similar mechanisms should underlie linguistic processes and other complex serial behaviors.”

“These findings suggest differential roles for the pre-SMA and SMA in speech, which has also been demonstrated elsewhere (Alario, Chainay, Lehericy, & Cohen, 2006 ).”

“Finally, Shima and Tanji (2000) found that only 6% of pre-SMA cells were selective to particular movements as opposed to 61% of cells in the SMA, indicating a cognitivemotor functional division.”

“Medium spiny neurons send inhibitory projections to cells in the pallidum including the globus pallidus internal (GPi) segment, which are tonically active and inhibitory to cells in the thalamus, which in turn project back to cortex (eg, Deniau & Chevalier, 1985 ).”

“, 2000), and both structural and functional abnormalities have been observed in the caudate in patients with inherited verbal dyspraxia characterized by particular difficulties with complex speech sequences (Vargha-Khadem et al., 1998; Watkins et al., 2002).”

“A syllable frequency effect, in which frequently encountered syllables are produced with a shorter latency than uncommon (but well-formed) syllables, has been reported by several researchers (Cholin, Levelt, & Schiller, 2006; Laganaro & Alario, 2006; Alario et al., 2004; Carreiras & Perea, 2004; Levelt & Wheeldon, 199…”

“…in sequencing motor acts (e.g., Harrington & Haaland, 1998), and abnormalities in these regions variously impact speech production (Murdoch, 2001; Kent, 2000), with some patients having particular Bohland, Bullock, and Guenther 1507 D o w n l o a d e d f r o m h t t p : / / m i t p r c . s i l v…”

“Mink (1996) and Mink and Thach (1993) outlined a conceptual model of BG function, suggesting that BG loops are used to selectively enable a motor program for output among competing alternatives.”

“MacKay (1970), in his study of spoonerisms, or phoneme exchange errors (e.g., saying “heft lemisphere” instead of the intended “left hemisphere”), noted the prominence of the syllable position constraint, in which exchanges are greatly biased to occur between phonemes occupying the same positional…”

“Locke (1997) presented a theory of neurolinguistic development involving four stages: (1) vocal learning, (2) utterance acquisition,”

“total activation distributed among the representation for planned items (Averbeck et al., 2002; Cisek & Kalaska, 2002).”

“Bohland and Guenther (2006) described differences between anterior and posterior medial areas, with the pre-SMA increasing activity for more complex syllable frames (e.g., CCCV3 vs. CV) and with the SMA increasing activity during overt speaking trials relative to preparationonly trials.”

“In this version of the model, we have not fully explored the parameter space to provide particularly optimal settings but reported simulations use the same parameter set (excepting noise).”

“Such delays in the production model have been considered by Guenther et al. (2006). Alternatively, in covert or internal speech, this completion signal might arrive from elsewhere, allowing the model to proceed through SSM programs without overtly articulating them.”

“We plan to explore the probable role of the cerebellum in phonological and phonetic processes (eg, Ackermann, 2008 ), including a role in on-line sequencing, for example, by fast parallel loading of phonological memory buffers (cf.”

“These correspond to a generic syllable template, such as that introduced by Fudge (1969) and used in the model of verbal STM introduced by Hartley and Houghton (1996).”

“Construction of the model was guided by previous theoretical work as well as clinical and experimen- tal results, most notably a companion fMRI study (Bohland & Guenther, 2006).”

“A number of concrete theoretical proposals have emerged to model serial behaviors (see Bullock, 2004; Rhodes, Bullock, Verwey, Averbeck, & Page, 2004; Houghton & Hartley, 1995).”

“The proposal that two loops through the BG, one mediated by the head of the caudate nucleus and one mediated by the putamen, are important in cognitive and motor aspects of speech production, respectively, was supported by intraoperative stimulation results demonstrating dysarthria and articulatory deficits when stimu…”

“…d f b y g u e s t o n 1 8 M a y 2 0 2 1 D ow nloaded from http://direct.m it.edu/jocn/article-pdf/22/7/1504/1938835/jocn.2009.21306.pdf by guest on 22 August 2021 stereotyped, however, readout by serial or “synfire” chains (e.g., Pulvermüller, 1999, 2002; Abeles, 1991) can offer greater efficiency.”

“These correspond to a generic syllable template, such as that introduced by Fudge (1969) and used in the model of verbal STM introduced by Hartley and Houghton (1996).”

“A similar region in left dorsal inferior frontal gyrus has been suggested to be involved in sequencing discrete units, including phonemes (Gelfand&Bookheimer, 2003), and in phonological encoding tasks (Papoutsi et al., 2009; Chein & Fiez, 2001; Burton, Small, & Blumstein, 2000; Poldrack et al., 1999).”

“Because choice of syllable frames in the pre-SMA “starts” the productionprocess, damagehere could result in reductions in self-initiated speech ( Jonas, 1981, 1987) but also may result in “frame deficiencies”— perhaps taking the form of reducing complex frame types to simpler ones.”

“Further analyses have shown a partial normalization of total activation distributed among the representation for planned items (Averbeck et al., 2002; Cisek & Kalaska, 2002).”

“Also found in the striatum, but less prevalent (only 2–3% of striatal cells in rats, but perhaps as many as 23% in humans; Graveland, 1985), are heterogeneous interneurons, many of which exhibit resting firing rates and receive cortical, thalamic, and dopaminergic input (Tepper, Koos, & Wilson,…”

“Treiman and Danis (1988) also noted that during nonword repetition, most errors are phonemic substitutions that preserve syllable structure.”

“Such action selection models (also Gurney, Prescott, & Redgrave, 2001a, 2001b; Kropotov & Etlinger, 1999; Redgrave, Prescott, & Gurney, 1999), which suggest that the BG do not generate movements but rather select and enable them, are relevant for sequence performance.”

“…in which frequently encountered syllables are produced with a shorter latency than uncommon (but well-formed) syllables, has been reported by several researchers (Cholin, Levelt, & Schiller, 2006; Laganaro & Alario, 2006; Alario et al., 2004; Carreiras & Perea, 2004; Levelt & Wheeldon, 1994).”

“Vousden et al. (2000) presented a similarly motivated model that is derived from a previous proposal for serial recall (Brown et al., 2000).”

“…are based on integrating the sparse available data from clinical and functional imaging studies and from inferences drawn from nonspeech sequencing tasks in other species, under the assumption that similar mechanisms should underlie linguistic processes and other complex serial behaviors.”

“Damage to the BG planning loop may impact selection and notably the timing of selection processes in phonological encoding, which is consistent with someobservations (Kreisler et al., 2000; Pickett et al., 1998).”

“Recently, this class of CQ models has received substantial support from direct neurophysiological recordings in monkeys (Averbeck, Chafee, Crowe, & Georgopoulos, 2003) and from chronometric analyses of seriation errors (Farrell & Lewandowsky, 2004).”

“…(in this case a sequence of the constituent syllable positions within a syllable frame) and another type that codes for a specific serial position within that sequence, are similar to cells that have been identified in the pre-SMA in monkey studies (Shima & Tanji, 2000; Clower & Alexander, 1998).”

“This is consistent with a hypothesis that this region contains a representation of a forthcoming speech plan.”

“A number of concrete theoretical proposals have emerged to model serial behaviors (see Bullock, 2004; Rhodes, Bullock, Verwey, Averbeck, & Page, 2004; Houghton & Hartley, 1995).”

“The architecture within BG loops is intricate (e.g., Parent & Hazrati, 1995), but here we adopt a simplified view to limit the modelʼs overall complexity.”

“The cerebellum may also be involved in the generation of prosody (Spencer & Slocomb, 2007), along with other structures, and future instantiations of the GODIVA model should strive to explain how prosody and stress can be encoded at the phonological and phonetic levels.”

“A shortcoming of previous theoretical psycholinguistic proposals has been their general failure to account for how linguistic behavior can emerge from specific neural structures (Nadeau, 2001).”

“Several concerns arise from the modelʼs timing, association, and recall processes; see the critiques of this class of models in Lewandowsky, Brown, Wright, and Nimmo (2006) and Agam, Bullock, and Sekuler (2005).”

“Explicit calls for bridging this latter gap have been made in the study of communication disorders (McNeil, Pratt, & Fossett, 2004;Ziegler, 2002).”

“…BG are involved in sequencing motor acts (e.g., Harrington & Haaland, 1998), and abnormalities in these regions variously impact speech production (Murdoch, 2001; Kent, 2000), with some patients having particular Bohland, Bullock, and Guenther 1507 D o w n l o a d e d f r o m h t t p : / / m i t…”

“Lesions to the medial wall cause speech problems (Pai, 1999; Ziegler, Kilian, & Deger, 1997; Jonas, 1981, 1987), usually resulting in reduced propositional speech with nonpropositional speech (e.”

“Several concerns arise from the model’s timing, association and recall processes; see the critiques of this class of models in Agam et al. (2005) and Lewandowsky, Brown, Wright, & Nimmo (2006).”

“■”

“Such models either require the ability to “label” a positional node with a particular representation or component item or require a set of all possible representations to be available at all serial positions, which is often infeasible.”

“The BG are involved in sequencing motor acts (e.g., Harrington & Haaland, 1998), and abnormalities in these regions variously impact speech production (Murdoch, 2001; Kent, 2000), with some patients having particular Bohland, Bullock, and Guenther 1507 D o w n l o a d e d f r o m h t t p : / / m i…”

“This irreducibility was supported by the finding that very young children make far fewer slips of the tongue than adult speakers (Warren, 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-”