The DIVA model: A neural theory of speech acquisition and production

“Similarly, comparisons of auditory responses during self-produced speech and while listening to recordings of one’s own speech indicate attenuation of auditory cortex responses during speech production (Curio, Neuloh, Numminen, Jousmaki, & Hari, 2000; Heinks-Maldonado, Mathalon, Gray, & Ford, 2005;…”

“1 Performance of these motor programs relies on contributions from bilateral premotor, motor, and subcortical regions (see below), areas that are active bilaterally during normal speech production.”

“Blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI; Belliveau et al., 1992; Kwong et al., 1992; Ogawa et al.,”

“Similarly, comparisons of auditory responses during self-produced speech and while listening to recordings of one’s own speech indicate attenuation of auditory cortex responses during speech production (Curio, Neuloh, Numminen, Jousmaki, & Hari, 2000; Heinks-Maldonado, Mathalon, Gray, & Ford, 2005;…”

“1 Performance of these motor programs relies on contributions from bilateral premotor, motor, and subcortical regions (see below), areas that are active bilaterally during normal speech production.”

“This mapping from desired sensory outcome to the appropriate motor action is an inverse kinematic transformation and is often referred to as an inverse model (e.g., Kawato, 1999; Wolpert & Kawato, 1998).”

“Evidence of mirror neurons in humans has implicated left precentral gyrus for grasping actions (Tai, Scherfler, Brooks, Sawamoto, & Castiello, 2004), and left opercular inferior frontal gyrus for finger movements (Iacoboni et al., 1999).”

“Von Holst and Mittelstaedt (1950) proposed the ‘principle of reafference’ in which a copy of the expected sensory consequences of a motor command, termed an efference copy, was subtracted from the realised sensory consequences.”

“For this purpose, the proposed locations of model components have been mapped to anatomical landmarks of the canonical brain provided with the SPM image analysis software package (Friston et al, 1995 ; <ext-link ext-link-type="uri" xmlns:xlink="http://www.”

“Mapping the model’s components onto this reference, then, provides a convenient means to compare the results of a large pool of neuroimaging experiments from a common theoretical framework, a framework that accounts for a wide range of data from diverse experimental modalities.”

“The goal of our research programme over the past 16 years has been to improve our understanding of the neural mechanisms that underlie speech motor control.”

“This mapping from desired sensory outcome to the appropriate motor action is an inverse kinematic transformation and is often referred to as an inverse model (e.g., Kawato, 1999; Wolpert & Kawato, 1998).”

“The somatosensory target and state maps lie in ventral supramarginal gyrus, a region Hickok and colleagues (e.g., Hickok & Poeppel, 2004) have argued supports the integration of speech motor commands and sensory feedback.”

“# 2010 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business http://www.psypress.com/lcp DOI: 10.1080/01690960903498424 Indefrey & Levelt, 2004; Turkeltaub, Eden, Jones, & Zeffiro, 2002).”

“1 Performance of these motor programs relies on contributions from bilateral premotor, motor, and subcortical regions (see below), areas that are active bilaterally during normal speech production.”

“Predictions from the model have guided studies of the role of auditory feedback in normally hearing persons, deaf persons, and persons who have recently regained some hearing through the use of cochlear implants (Lane et al., 2007a; Perkell et al., 2000, 2004a, 2004b, 2007).”

“The DIVA model: A neural theory of speech acquisition and production”

“Local field potentials are thought to reflect local synaptic activity, i.e., a weighted sum of the inputs to a given region (Raichle & Mintun, 2006).”

“Projections such as these, which predict the sensorimotor state resulting from a movement, are typically described as representing a forward model of the movement (e.g., Davidson & Wolpert, 2005; Desmurget & Grafton, 2000; Kawato, 1999; Miall & Wolpert, 1996).”

“Browman & Goldstein, 1989 ) for that speech sound.”

“Broca’s early findings linking left inferior frontal damage with speech production deficits have been corroborated by a large body of lesion studies (Dronkers, 1996; Duffy, 2005; Hillis et al., 2004; Kent & Tjaden, 1997).”

“…velocity cells is analogous to the process of ‘phonetic encoding’ as conceptualised by Levelt and colleagues (e.g., Levelt, Roelofs, & Meyer, 1999; Levelt & Wheeldon, 1994); i.e., it transforms a phonological input from adjacent inferior frontal cortex into the set of feedforward motor…”

“Reciprocal pathways between inferior frontal and auditory and somatosensory cortex have been demonstrated in humans (Makris et al., 2005; Matsumoto et al., 2004) and non-human primates (Morel & Kaas, 1992; Ojemann, 1991; Romanski et al.”

“A dominant role for the left hemisphere has been a hallmark of language processing models for several decades (Geschwind, 1970).”

“…cortex have been demonstrated in humans (Makris et al., 2005; Matsumoto et al., 2004) and non-human primates (Morel & Kaas, 1992; Ojemann, 1991; Romanski et al., 1999; Schmahmann & Pandya, 2006); also see Duffau (2008) for a description of the putative fronto-parietal and frontotemporal…”

“Neuroimaging studies of motor learning have noted cerebellar activity that is associated with the size or frequency of sensory error (e.g., Blakemore, Frith, & Wolpert, 2001; Blakemore, Wolpert, & Frith, 1999; Diedrichsen, Hashambhoy, Rane, & Shadmehr, 2005; Flament, Ellermann, Kim, Ugurbil, & Ebner, 1996; Grafton et…”

“Model components were mapped to locations in the Montreal Neurological Institute (MNI; Mazziotta et al., 2001) standard reference frame based on relevant neuroanatomical and neurophysiological studies (Guenther et al., 2006).”

“Maeda, S. (1990). Compensatory articulation during speech: Evidence from the analysis and synthesis of vocal tract shapes using an articulatory model.”

“…inverse kinematics (e.g., Kawato, 1999; Wolpert & Kawato, 1998), a role for which it is anatomically well-suited; the cerebellum receives inputs from higher-order auditory and somatosensory areas (e.g., Schmahmann & Pandya, 1997), and projects heavily to the motor cortex (Middleton & Strick, 1997).”

“Support for these modifications and the impact they have on the model are discussed below.”

“…past decade and a half of imaging research has provided a tremendous amount of functional data regarding the brain regions involved in speech (e.g., Fiez & Petersen, 1998; Ghosh, Bohland, & Guenther, 2003; Indefrey & Levelt, 2004; Riecker et al., 2000b; Soros, Sokoloff, Bose, McIntosh, Graham, &…”

“The SMA is strongly interconnected with lateral motor and premotor cortex and the basal ganglia (Jurgens, 1984; Lehericy et al., 2004; Luppino, Matelli, Camarda, & Rizzolatti, 1993; Matsumoto et al., 2004, 2007).”

“…1996; Ghacibeh & Heilman, 2003; Kotz et al., 2003; Mitchell, Elliott, Barry, Cruttenden, & Woodruff, 2003; Pihan, Altenmuller, & Ackermann, 1997; Ross & Mesulam, 1979; Williamson, Harrison, Shenal, Rhodes, & Demaree, 2003), though the view of affective prosody as a unitary, purely right…”

“Once trained, the model takes a speech sound as input, and generates a time varying sequence of articulator positions that command movements of the simulated vocal tract that produce the desired sound.”

“It has been argued by many that the cerebellum uses sensory error to build forward models that generate sensory predictions (Blakemore et al., 2001; Imamizu et al., 2000; Kawato et al., 2003; O’Reilly, Mesulam, & Nobre, 2008), the role of projections from the speech sound map to sensory target maps…”

“…Arieli, Hasson, Fried, & Malach, 2005), consensus is building around the hypotheses that BOLD signal is correlated with local field potentials (Goense & Logothetis, 2008; Logothetis, Pauls, Augath, Trinath, & Oeltermann, 2001; Mathiesen, Caesar, Akgoren, & Lauritzen, 1998; Viswanathan &…”

“The synaptic weights are learned during a babbling phase meant to coarsely represent that typically experienced by a normally developing infant (e.g., Oller & Eilers, 1988).”

“These data and recent imaging findings have led a number of investigators to conclude that the SMA plays a critical role in controlling the initiation of speech motor commands (e.g., Alario, Chainay, Lehericy, & Cohen, 2006; Bohland & Guenther, 2006; Jonas, 1987; Ziegler et al., 1997).”

“The mapping from a cell in the speech sound map to the articulator velocity cells is analogous to the process of ‘phonetic encoding’ as conceptualised by Levelt and colleagues (eg, Levelt, Roelofs, & Meyer, 1999; Levelt & Wheeldon, 1994 ); ie, it transforms a phonological input from adjacent inferior frontal cortex in…”

“Cells in the articulator position maps are hypothesised to correspond to ‘tonic’ neurons that have been identified in monkey primary motor cortex (e.g., Kalaska et al., 1989).”

“Wise and colleagues, using positron emission tomography (PET) to indirectly assess neural activity, noted reduced superior temporal gyrus activation during speech production compared with a listening task (Wise, Greene, Buchel, & Scott, 1999 ).”

“This hypothesised role for ventral parietal cortex during speech production is analogous to the visual-motor integration role associated with more dorsal parietal regions during limb movements (Andersen, 1997 ; Rizzolatti, Fogassi, & Gallese, 1997 ).”

“…in the speech sound map to the articulator velocity cells is analogous to the process of ‘phonetic encoding’ as conceptualised by Levelt and colleagues (e.g., Levelt, Roelofs, & Meyer, 1999; Levelt & Wheeldon, 1994); i.e., it transforms a phonological input from adjacent inferior frontal cortex…”

“Thus, as DIVA has come to account for a wide range of speech production phenomena (e.g., Callan et al., 2000; Guenther, 1994, 1995; Guenther et al., 1998; Nieto-Castanon et al., 2005), it does so from a unified quantitative and neurobiologically grounded framework.”

“Broca’s early findings linking left inferior frontal damage with speech production deficits have been corroborated by a large body of lesion studies (Dronkers, 1996; Duffy, 2005; Hillis et al., 2004; Kent & Tjaden, 1997).”

“Experiments are designed to test these predictions, and the empirical findings are, in turn, used to further refine the model.”

“Neuroimaging studies of speech production in persons who stutter consistently demonstrate increased right hemisphere activation relative to normal speakers in the precentral and inferior frontal gyrus regions (see Brown, Ingham, Ingham, Laird, & Fox, 2005 for review), the same frontal regions identified as part of the…”

“…of affective prosody, which appear to rely more on the right cerebral hemisphere than the left hemisphere (Adolphs, Damasio, & Tranel, 2002; Buchanan et al., 2000; George et al., 1996; Ghacibeh & Heilman, 2003; Kotz et al., 2003; Mitchell, Elliott, Barry, Cruttenden, & Woodruff, 2003;…”

“Based on these findings, two sets of cells representing laryngeal parameters of the Maeda articulator model (Maeda, 1990) associated with laryngeal functions have been assigned to MNI locations: cells in ventrolateral precentral gyrus (labelled Larynx, Extrinsic in Table 1) represent larynx height, whereas cells in th…”

“…carryover coarticulation, velocity/ distance relationships, speaking rate effects, and speaking skill acquisition and retention throughout development (e.g., Callan, Kent, Guenther, & Vorperian, 2000; Guenther, 1994, 1995; Guenther et al., 2006; Guenther et al., 1998; Nieto-Castanon et al., 2005).”

“Modulation of pitch, loudness, duration, and rhythm convey meaningful linguistic and affective cues (Bolinger, 1961, 1989; Lehiste, 1970, 1976; Netsell, 1973; Shriberg & Kent, 1982).”

“…Hasson, Fried, & Malach, 2005), consensus is building around the hypotheses that BOLD signal is correlated with local field potentials (Goense & Logothetis, 2008; Logothetis, Pauls, Augath, Trinath, & Oeltermann, 2001; Mathiesen, Caesar, Akgoren, & Lauritzen, 1998; Viswanathan & Freeman, 2007).”

“…speculated that a representation of sensory errors in the cerebellum drives corrective motor commands (Grafton et al., 2008; Penhune & Doyon, 2005) and contributes to feedback-based motor learning (Ito, 2000; Tseng, Diedrichsen, Krakauer, Shadmehr, & Bastian, 2007; Wolpert, Miall, & Kawato, 1998).”

“These data and recent imaging findings have led a number of investigators to conclude that the SMA plays a critical role in controlling the initiation of speech motor commands (eg, Alario, Chainay, Lehericy, & Cohen, 2006 ; Bohland & Guenther, 2006 ; Jonas, 1987 ; Ziegler et al, 1997 ).”

“The SMA is reciprocally connected with the basal ganglia, another region widely believed to contribute to gating motor commands (eg, Albin, Young, & Penney, 1995 ; Pickett, Kuniholm, Protopapas, Friedman, & Lieberman, 1998 ; Van Buren, 1963 ).”

“Evidence of mirror neurons in humans has implicated left precentral gyrus for grasping actions (Tai, Scherfler, Brooks, Sawamoto, & Castiello, 2004 ), and left opercular inferior frontal gyrus for finger movements (Iacoboni et al, 1999 ).”

“…in humans (Makris et al., 2005; Matsumoto et al., 2004) and non-human primates (Morel & Kaas, 1992; Ojemann, 1991; Romanski et al., 1999; Schmahmann & Pandya, 2006); also see Duffau (2008) for a description of the putative fronto-parietal and frontotemporal pathways involved in language processing.”

“A wide body of evidence suggests such a mechanism plays an important role in the motor control of eye and hand movements, as well as speech (e.g., Bays, Flanagan, & Wolpert, 2006; Cullen, 2004; Heinks-Maldonado & Houde, 2005; Reppas, Usrey, & Reid, 2002; Roy & Cullen, 2004; Voss, Ingram, Haggard, &…”

“The SMA is strongly interconnected with lateral motor and premotor cortex and the basal ganglia (Jurgens, 1984; Lehericy et al., 2004; Luppino, Matelli, Camarda, & Rizzolatti, 1993; Matsumoto et al., 2004, 2007).”

“The SMA is strongly interconnected with lateral motor and premotor cortex and the basal ganglia (Jurgens, 1984; Lehericy et al., 2004; Luppino, Matelli, Camarda, & Rizzolatti, 1993; Matsumoto et al., 2004, 2007).”

“…data regarding the brain regions involved in speech (e.g., Fiez & Petersen, 1998; Ghosh, Bohland, & Guenther, 2003; Indefrey & Levelt, 2004; Riecker et al., 2000b; Soros, Sokoloff, Bose, McIntosh, Graham, & Stuss, 2006; Turkeltaub et al., 2002), including the identification of a ‘minimal…”

“The SMA is strongly interconnected with lateral motor and premotor cortex and the basal ganglia (Jurgens, 1984; Lehericy et al., 2004; Luppino, Matelli, Camarda, & Rizzolatti, 1993; Matsumoto et al., 2004, 2007).”

“The map consists of 10 pairs of antagonistic cells2 that correspond to parameters of the Maeda vocal tract that determine lip protrusion, upper and lower lip height, jaw height, tongue height, tongue shape, tongue body position, tongue tip location, larynx height, and glottal opening and pressure.”

“Based on recent imaging work (Brown, Ngan, & Liotti, 2008 ; Olthoff, Baudewig, Kruse, & Dechent, 2008 ), additional motor cortex cells have been added to the model that represent the intrinsic laryngeal muscles.”

“It has been hypothesised that stuttering involves excessive reliance upon auditory feedback control due to poor feedforward commands (Max et al., 2004).”

“Support for these modifications and the impact they have on the model are discussed below.”

“Projections such as these, which predict the sensorimotor state resulting from a movement, are typically described as representing a forward model of the movement (e.g., Davidson & Wolpert, 2005; Desmurget & Grafton, 2000; Kawato, 1999; Miall & Wolpert, 1996).”

“This area has been proposed to correspond to the caudal portion of ventral inferior frontal gyrus (Brodmann’s area 44) in the human (see Binkofski & Buccino, 2004; Rizzolatti & Arbib, 1998).”

“The model has proven to be a valuable tool for studying the mechanisms underlying normal (Callan et al, 2000 ; Lane et al, 2007b ; Perkell et al, 2000 , 2004a, 2004b, 2007 ; Villacorta, Perkell, & Guenther, 2007 ) and disordered speech (Max et al, 2004 ; Robin et al, 2008 ; Terband et al, 2008 ).”

“One of the more consistent findings in the literature concerns perception and production of affective prosody, which appear to rely more on the right cerebral hemisphere than the left hemisphere (Adolphs, Damasio, & Tranel, 2002; Buchanan et al., 2000; George et al., 1996; Ghacibeh & Heilman, 2003; Kotz et al., 2003;…”

“It implies that damage to the left inferior frontal cortex is more commonly associated with speech disruptions than damage to the same region in the right hemisphere because feedforward motor programs are disrupted.”

“Thus, as DIVA has come to account for a wide range of speech production phenomena (e.g., Callan et al., 2000; Guenther, 1994, 1995; Guenther et al., 1998; Nieto-Castanon et al., 2005), it does so from a unified quantitative and neurobiologically grounded framework.”

“The model has also been employed in investigations of the etiology of stuttering (Max, Guenther, Gracco, Ghosh, & Wallace, 2004), and acquired apraxia of speech (Robin et al., 2008; Terband, Maassen, Brumberg, & Guenther, 2008).”

“However, rather than being limited to a repository of motor programs for frequently produced syllables, as Levelt proposed, the speech sound map also represents common syllabic, sub-syllabic (phonemes), and multi-syllabic speech sounds (e.g., words, phrases).”

“It is widely held that the cerebellum is involved with the learning and maintenance of feedforward motor commands (though see Grafton et al, 2008 ; Kawato, 1999 ; Ohyama, Nores, Murphy, & Mauk, 2003 ).”

“…suggests such a mechanism plays an important role in the motor control of eye and hand movements, as well as speech (e.g., Bays, Flanagan, & Wolpert, 2006; Cullen, 2004; Heinks-Maldonado & Houde, 2005; Reppas, Usrey, & Reid, 2002; Roy & Cullen, 2004; Voss, Ingram, Haggard, & Wolpert, 2006).”

“…frontal and auditory and somatosensory cortex have been demonstrated in humans (Makris et al., 2005; Matsumoto et al., 2004) and non-human primates (Morel & Kaas, 1992; Ojemann, 1991; Romanski et al., 1999; Schmahmann & Pandya, 2006); also see Duffau (2008) for a description of the putative…”

“Studies have begun to explore putative sensory expectation projections from lateral frontal cortex to auditory cortex, establishing an inhibitory effect linked to ongoing articulator movements (eg, Heinks-Maldonado et al, 2006 ).”

“Additional activity is typically found in adjacent lateral cortex bilaterally (Bohland & Guenther, 2006 ; Ghosh et al, 2008 ; Riecker, Ackermann, Wildgruber, Dogil, & Grodd, 2000; Riecker, Wildgruber, Dogil, Grodd, & Ackermann, 2002 ; Tourville et al, 2008 ; Wildgruber, Ackermann, & Grodd, 2001 ), an area less commonl…”

“Predictions from the model have guided studies of the role of auditory feedback in normally hearing persons, deaf persons, and persons who have recently regained some hearing through the use of cochlear implants (Lane et al., 2007a; Perkell et al., 2000, 2004a, 2004b, 2007).”

“This work bridges the gap between computational models of the linguistic/phonological level of speech production (Dell, 1986; Hartley & Houghton, 1996; Levelt et al., 1999), and DIVA, which addresses production at the speech motor control level.”

“The model has also been employed in investigations of the etiology of stuttering (Max, Guenther, Gracco, Ghosh, & Wallace, 2004), and acquired apraxia of speech (Robin et al., 2008; Terband, Maassen, Brumberg, & Guenther, 2008).”

“, & Kawato, M. (2007). Reorganization of brain activity for”

“…a laryngeal representation in motor cortex has typically been associated with the ventrolateral extreme of the precentral gyrus (e.g., Duffy, 2005; Ludlow, 2005), an assumption based heavily upon findings from non-human primates (e.g. Simonyan & Jurgens, 2003) and supported by the intracortical…”

“Lesions to anterior vermal and paravermal cerebellum have been associated with disruptions of speech production (Ackermann, Vogel, Petersen, & Poremba, 1992 ; Urban et al, 2003 ), termed ataxic dysarthria, characterised by an impaired ability to produce speech with fluent timing and gestural coordination.”

“Predictions from the model have guided studies of the role of auditory feedback in normally hearing persons, deaf persons, and persons who have recently regained some hearing through the use of cochlear implants (Lane et al., 2007a; Perkell et al., 2000, 2004a, 2004b, 2007).”

“The model has been used to guide a number of behavioural and functional imaging studies of speech processing (e.g., Bohland & Guenther, 2006; Ghosh, Tourville & Guenther, 2008; Guenther et al., 1999; Lane et al., 2005, 2007a, 2007b; Nieto-Castanon, Guenther, Perkell, & Curtin, 2005; Perkell et al., 2004a, 2004b; Tourv…”

“Modulation of pitch, loudness, duration, and rhythm convey meaningful linguistic and affective cues (Bolinger, 1961, 1989; Lehiste, 1970, 1976; Netsell, 1973; Shriberg & Kent, 1982).”

“It has been speculated that a representation of sensory errors in the cerebellum drives corrective motor commands (Grafton et al., 2008; Penhune & Doyon, 2005) and contributes to feedback-based motor learning (Ito, 2000; Tseng, Diedrichsen, Krakauer, Shadmehr, & Bastian, 2007; Wolpert, Miall, &…”

“…of auditory response suppression during self-initiated vocalisations is provided by single unit recordings from non-human primates; for example, attenuation of auditory cortical responses prior to self-initiated vocalisations has been demonstrated in the marmoset (Eliades & Wang, 2003, 2005).”

“…Wolpert, 2001; Blakemore, Wolpert, & Frith, 1999; Diedrichsen, Hashambhoy, Rane, & Shadmehr, 2005; Flament, Ellermann, Kim, Ugurbil, & Ebner, 1996; Grafton et al., 2008; Imamizu et al., 2000; Imamizu, Higuchi, Toda, & Kawato, 2007; Miall & Jenkinson, 2005; Schreurs et al., 1997; Tesche & Karhu,…”

“This hypothesis is consistent with the effects of fluency-inducing therapy on BOLD responses; successful treatment has been associated with a shift toward more normal, left-lateralised frontal activation (De Nil, Kroll, Lafaille, & Houle, 2003 ; Neumann et al, 2005 ).”

“The model has proven to be a valuable tool for studying the mechanisms underlying normal (Callan et al., 2000; Lane et al., 2007b; Perkell et al., 2000, 2004a, 2004b, 2007; Villacorta, Perkell, & Guenther, 2007) and disordered speech (Max et al., 2004; Robin et al., 2008; Terband et al., 2008).”

“…debate over which and to what extent prosodic feature control is lateralised (e.g., Doherty, West, Dilley, Shattuck-Hufnagel, & Caplan, 2004; Emmorey, 1987; Gandour et al., 2003; Meyer, Alter, Friederici, Lohmann, & von Cramon, 2002; Stiller et al., 1997; Walker, Pelletier, & Reif, 2004).”

“This hypothesis is consistent with the effects of fluency-inducing therapy on BOLD responses; successful treatment has been associated with a shift toward more normal, leftlateralised frontal activation (De Nil, Kroll, Lafaille, & Houle, 2003; Neumann et al., 2005).”

“Neuroimaging studies of motor learning have noted cerebellar activity that is associated with the size or frequency of sensory error (e.g., Blakemore, Frith, & Wolpert, 2001; Blakemore, Wolpert, & Frith, 1999; Diedrichsen, Hashambhoy, Rane, & Shadmehr, 2005; Flament, Ellermann, Kim, Ugurbil, & Ebner, 1996; Grafton et…”

“…debate over which and to what extent prosodic feature control is lateralised (e.g., Doherty, West, Dilley, Shattuck-Hufnagel, & Caplan, 2004; Emmorey, 1987; Gandour et al., 2003; Meyer, Alter, Friederici, Lohmann, & von Cramon, 2002; Stiller et al., 1997; Walker, Pelletier, & Reif, 2004).”

“Our findings corroborate characterisations of AOS as a disruption of the use and development of speech motor programs (Ballard, Granier, & Robin, 2000 ; McNeil, Robin, & Schmidt, 2007 ) and suggest that rehabilitative treatments focused on restoring motor programs, eg, sound production treatment (Wambaugh, Duffy, McNe…”

“Blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI; Belliveau et al., 1992; Kwong et al., 1992; Ogawa et al.,”

“The SMA is reciprocally connected with the basal ganglia, another region widely believed to contribute to gating motor commands (eg, Albin, Young, & Penney, 1995 ; Pickett, Kuniholm, Protopapas, Friedman, & Lieberman, 1998 ; Van Buren, 1963 ).”

“…to anterior vermal and paravermal cerebellum have been associated with disruptions of speech production (Ackermann, Vogel, Petersen, & Poremba, 1992; Urban et al., 2003), termed ataxic dysarthria, characterised by an impaired ability to produce speech with fluent timing and gestural coordination.”

“…extreme of the precentral gyrus (e.g., Duffy, 2005; Ludlow, 2005), an assumption based heavily upon findings from non-human primates (e.g. Simonyan & Jurgens, 2003) and supported by the intracortical mapping studies performed by Penfield and colleagues in humans prior to epilepsy surgery…”

“Additional activity is typically found in adjacent lateral cortex bilaterally (Bohland & Guenther, 2006 ; Ghosh et al, 2008 ; Riecker, Ackermann, Wildgruber, Dogil, & Grodd, 2000; Riecker, Wildgruber, Dogil, Grodd, & Ackermann, 2002 ; Tourville et al, 2008 ; Wildgruber, Ackermann, & Grodd, 2001 ), an area less commonl…”

“…& Tanji, 2000), intervals between specific movements within in a sequence (Shima & Tanji, 2000), the ordinal position of movements within a sequence (Clower & Alexander, 1998), and the number of items remaining in a sequence (Sohn & Lee, 2007) have been noted in recordings of neurons in the SMA.”

“These data and recent imaging findings have led a number of investigators to conclude that the SMA plays a critical role in controlling the initiation of speech motor commands (e.g., Alario, Chainay, Lehericy, & Cohen, 2006; Bohland & Guenther, 2006; Jonas, 1987; Ziegler et al., 1997).”

“…data regarding the brain regions involved in speech (e.g., Fiez & Petersen, 1998; Ghosh, Bohland, & Guenther, 2003; Indefrey & Levelt, 2004; Riecker et al., 2000b; Soros, Sokoloff, Bose, McIntosh, Graham, & Stuss, 2006; Turkeltaub et al., 2002), including the identification of a ‘minimal…”

“Other imaging studies of speech production that have included a perturbed auditory feedback condition have demonstrated greater right hemisphere involvement in auditory feedback-based control of speech (eg, Fu et al, 2006 ; Toyomura et al, 2007 ).”

“E-mail: guenther@cns.bu.edu Supported by the National Institute on Deafness and other Communication Disorders (R01 DC02852, F. Guenther PI).”

“The relative weight of feedforward and feedback commands in the overall motor command is dependent upon the size of the error signal since this determines the size of the feedback control contribution.”

“Ipsilateral and contralateral premotor-to-motor projections that would underlie this hypothesised connectivity have been demonstrated in monkeys (e.g., Dancause et al., 2006, 2007; Fang, Stepniewska, & Kaas, 2005; Stepniewska, Preuss, & Kaas, 2006).”

“Ipsilateral and contralateral premotor-to-motor projections that would underlie this hypothesised connectivity have been demonstrated in monkeys (eg, Dancause et al, 2006 , 2007 ; Fang, Stepniewska, & Kaas, 2005 ; Stepniewska, Preuss, & Kaas, 2006 ).”

“…& Tanji, 2000), intervals between specific movements within in a sequence (Shima & Tanji, 2000), the ordinal position of movements within a sequence (Clower & Alexander, 1998), and the number of items remaining in a sequence (Sohn & Lee, 2007) have been noted in recordings of neurons in the SMA.”

“The SMA is reciprocally connected with the basal ganglia, another region widely believed to contribute to gating motor commands (e.g., Albin, Young, & Penney, 1995; Pickett, Kuniholm, Protopapas, Friedman, & Lieberman, 1998; Van Buren, 1963).”

“…suggests such a mechanism plays an important role in the motor control of eye and hand movements, as well as speech (e.g., Bays, Flanagan, & Wolpert, 2006; Cullen, 2004; Heinks-Maldonado & Houde, 2005; Reppas, Usrey, & Reid, 2002; Roy & Cullen, 2004; Voss, Ingram, Haggard, & Wolpert, 2006).”

“…2001; Blakemore, Wolpert, & Frith, 1999; Diedrichsen, Hashambhoy, Rane, & Shadmehr, 2005; Flament, Ellermann, Kim, Ugurbil, & Ebner, 1996; Grafton et al., 2008; Imamizu et al., 2000; Imamizu, Higuchi, Toda, & Kawato, 2007; Miall & Jenkinson, 2005; Schreurs et al., 1997; Tesche & Karhu, 2000).”

“…carryover coarticulation, velocity/ distance relationships, speaking rate effects, and speaking skill acquisition and retention throughout development (e.g., Callan, Kent, Guenther, & Vorperian, 2000; Guenther, 1994, 1995; Guenther et al., 2006; Guenther et al., 1998; Nieto-Castanon et al., 2005).”

“Ipsilateral and contralateral premotor-to-motor projections that would underlie this hypothesised connectivity have been demonstrated in monkeys (e.g., Dancause et al., 2006, 2007; Fang, Stepniewska, & Kaas, 2005; Stepniewska, Preuss, & Kaas, 2006).”

“Brown et al. (2008) and Olthoff et al. (2008) have since demonstrated a bilateral representation in a more dorsal region of motor cortex adjacent to the lip area and near a second ‘vocalisation’ region identified by Penfield and Roberts (1959, p. 200).”

“These projections encode the time-varying sensory expectations, or targets, associated with the active speech sound map cell.”

“The map consists of 10 pairs of antagonistic cells2 that correspond to parameters of the Maeda vocal tract that determine lip protrusion, upper and lower lip height, jaw height, tongue height, tongue shape, tongue body position, tongue tip location, larynx height, and glottal opening and pressure.”

“The model has been used to guide a number of behavioural and functional imaging studies of speech processing (eg, Bohland & Guenther, 2006 ; Ghosh, Tourville & Guenther, 2008; Guenther et al, 1999 ; Lane et al, 2005 , 2007a, 2007b; Nieto-Castanon, Guenther, Perkell, & Curtin, 2005; Perkell et al, 2004a , 2004b; Tourvi…”

“Support for these modifications and the impact they have on the model are discussed below.”

“…debate over which and to what extent prosodic feature control is lateralised (e.g., Doherty, West, Dilley, Shattuck-Hufnagel, & Caplan, 2004; Emmorey, 1987; Gandour et al., 2003; Meyer, Alter, Friederici, Lohmann, & von Cramon, 2002; Stiller et al., 1997; Walker, Pelletier, & Reif, 2004).”

“Based on recent imaging work (Brown, Ngan, & Liotti, 2008; Olthoff, Baudewig, Kruse, & Dechent, 2008), additional motor cortex cells have been added to the model that represent the intrinsic laryngeal muscles.”

“…of how speech and language are rooted in the brain as extensive research has shown how many other cortical and subcortical regions besides Broca’s and Wernicke’s areas are involved in processing speech and language (Hickok and Poeppel, 2007; Tourville and Guenther, 2011; Ueno et al., 2011).”