1
|
Parrell B, Naber C, Kim OA, Nizolek CA, McDougle SD. Audiomotor prediction errors drive speech adaptation even in the absence of overt movement. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.13.607718. [PMID: 39185222 PMCID: PMC11343123 DOI: 10.1101/2024.08.13.607718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Observed outcomes of our movements sometimes differ from our expectations. These sensory prediction errors recalibrate the brain's internal models for motor control, reflected in alterations to subsequent movements that counteract these errors (motor adaptation). While leading theories suggest that all forms of motor adaptation are driven by learning from sensory prediction errors, dominant models of speech adaptation argue that adaptation results from integrating time-advanced copies of corrective feedback commands into feedforward motor programs. Here, we tested these competing theories of speech adaptation by inducing planned, but not executed, speech. Human speakers (male and female) were prompted to speak a word and, on a subset of trials, were rapidly cued to withhold the prompted speech. On standard trials, speakers were exposed to real-time playback of their own speech with an auditory perturbation of the first formant to induce single-trial speech adaptation. Speakers experienced a similar sensory error on movement cancelation trials, hearing a perturbation applied to a recording of their speech from a previous trial at the time they would have spoken. Speakers adapted to auditory prediction errors in both contexts, altering the spectral content of spoken vowels to counteract formant perturbations even when no actual movement coincided with the perturbed feedback. These results build upon recent findings in reaching, and suggest that prediction errors, rather than corrective motor commands, drive adaptation in speech.
Collapse
|
2
|
Beach SD, Johnson SA, Parrell B, Niziolek CA. Increased vowel contrast and intelligibility in connected speech induced by sensorimotor adaptation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.04.606537. [PMID: 39149284 PMCID: PMC11326165 DOI: 10.1101/2024.08.04.606537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Alterations to sensory feedback can drive robust adaptive changes to the production of consonants and vowels, but these changes often have no behavioral relevance or benefit to communication (e.g., making "head" more like "had"). This work aims to align the outcomes of adaptation with changes known to increase speech intelligibility - specifically, adaptations that increase the acoustic contrast between vowels in running speech. To this end, we implemented a vowel centralization feedback perturbation paradigm that pushes all vowels towards the center of vowel space, making them sound less distinct from one another. Speakers across the adult lifespan adapted to the centralization perturbation during sentence production, increasing the global acoustic contrast among vowels and the articulatory excursions for individual vowels. These changes persisted after the perturbation was removed, including after a silent delay, and showed robust transfer to words that were not present in the sentences. Control analyses demonstrated that these effects were unlikely to be due to explicit pronunciation strategies and occurred in the face of increasingly more rapid and less distinct production of familiar sentences. Finally, sentence transcription by crowd-sourced listeners showed that speakers' vowel contrast predicted their baseline intelligibility and that experimentally-induced increases in contrast predicted intelligibility gains. These findings establish the validity of a sensorimotor adaptation paradigm to implicitly increase vowel contrast and intelligibility in connected speech, an outcome that has the potential to enhance rehabilitation in individuals who present with a reduced vowel space due to motor speech disorders, such as the hypokinetic dysarthria associated with Parkinson's disease.
Collapse
Affiliation(s)
- Sara D. Beach
- Waisman Center, University of Wisconsin–Madison, Madison, WI, USA
| | | | - Benjamin Parrell
- Waisman Center, University of Wisconsin–Madison, Madison, WI, USA
- Department of Communication Sciences and Disorders, University of Wisconsin–Madison, Madison, WI, USA
- These authors contributed equally
| | - Caroline A. Niziolek
- Waisman Center, University of Wisconsin–Madison, Madison, WI, USA
- Department of Communication Sciences and Disorders, University of Wisconsin–Madison, Madison, WI, USA
- These authors contributed equally
- Lead contact
| |
Collapse
|
3
|
Li H, Chalavi S, Rasooli A, Rodríguez‐Nieto G, Seer C, Mikkelsen M, Edden RAE, Sunaert S, Peeters R, Mantini D, Swinnen SP. Baseline GABA+ levels in areas associated with sensorimotor control predict initial and long-term motor learning progress. Hum Brain Mapp 2024; 45:e26537. [PMID: 38140712 PMCID: PMC10789216 DOI: 10.1002/hbm.26537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 09/30/2023] [Accepted: 11/02/2023] [Indexed: 12/24/2023] Open
Abstract
Synaptic plasticity relies on the balance between excitation and inhibition in the brain. As the primary inhibitory and excitatory neurotransmitters, gamma-aminobutyric acid (GABA) and glutamate (Glu), play critical roles in synaptic plasticity and learning. However, the role of these neurometabolites in motor learning is still unclear. Furthermore, it remains to be investigated which neurometabolite levels from the regions composing the sensorimotor network predict future learning outcome. Here, we studied the role of baseline neurometabolite levels in four task-related brain areas during different stages of motor skill learning under two different feedback (FB) conditions. Fifty-one healthy participants were trained on a bimanual motor task over 5 days while receiving either concurrent augmented visual FB (CA-VFB group, N = 25) or terminal intrinsic visual FB (TA-VFB group, N = 26) of their performance. Additionally, MRS-measured baseline GABA+ (GABA + macromolecules) and Glx (Glu + glutamine) levels were measured in the primary motor cortex (M1), primary somatosensory cortex (S1), dorsolateral prefrontal cortex (DLPFC), and medial temporal cortex (MT/V5). Behaviorally, our results revealed that the CA-VFB group outperformed the TA-VFB group during task performance in the presence of augmented VFB, while the TA-VFB group outperformed the CA-VFB group in the absence of augmented FB. Moreover, baseline M1 GABA+ levels positively predicted and DLPFC GABA+ levels negatively predicted both initial and long-term motor learning progress in the TA-VFB group. In contrast, baseline S1 GABA+ levels positively predicted initial and long-term motor learning progress in the CA-VFB group. Glx levels did not predict learning progress. Together, these findings suggest that baseline GABA+ levels predict motor learning capability, yet depending on the FB training conditions afforded to the participants.
Collapse
Affiliation(s)
- Hong Li
- Movement Control and Neuroplasticity Research GroupGroup Biomedical Sciences, KU LeuvenLeuvenBelgium
- KU Leuven Brain Institute (LBI), KU LeuvenLeuvenBelgium
| | - Sima Chalavi
- Movement Control and Neuroplasticity Research GroupGroup Biomedical Sciences, KU LeuvenLeuvenBelgium
- KU Leuven Brain Institute (LBI), KU LeuvenLeuvenBelgium
| | - Amirhossein Rasooli
- Movement Control and Neuroplasticity Research GroupGroup Biomedical Sciences, KU LeuvenLeuvenBelgium
- KU Leuven Brain Institute (LBI), KU LeuvenLeuvenBelgium
| | - Geraldine Rodríguez‐Nieto
- Movement Control and Neuroplasticity Research GroupGroup Biomedical Sciences, KU LeuvenLeuvenBelgium
- KU Leuven Brain Institute (LBI), KU LeuvenLeuvenBelgium
| | - Caroline Seer
- Movement Control and Neuroplasticity Research GroupGroup Biomedical Sciences, KU LeuvenLeuvenBelgium
- KU Leuven Brain Institute (LBI), KU LeuvenLeuvenBelgium
| | - Mark Mikkelsen
- Department of RadiologyWeill Cornell MedicineNew YorkNew YorkUSA
| | - Richard A. E. Edden
- Russell H. Morgan Department of Radiology and Radiological ScienceJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- F. M. Kirby Research Center for Functional Brain ImagingKennedy Krieger InstituteBaltimoreMarylandUSA
| | - Stefan Sunaert
- KU Leuven Brain Institute (LBI), KU LeuvenLeuvenBelgium
- Department of Imaging and PathologyKU Leuven and University Hospital Leuven (UZ Leuven)LeuvenBelgium
| | - Ron Peeters
- Department of Imaging and PathologyKU Leuven and University Hospital Leuven (UZ Leuven)LeuvenBelgium
| | - Dante Mantini
- Movement Control and Neuroplasticity Research GroupGroup Biomedical Sciences, KU LeuvenLeuvenBelgium
- KU Leuven Brain Institute (LBI), KU LeuvenLeuvenBelgium
| | - Stephan P. Swinnen
- Movement Control and Neuroplasticity Research GroupGroup Biomedical Sciences, KU LeuvenLeuvenBelgium
- KU Leuven Brain Institute (LBI), KU LeuvenLeuvenBelgium
| |
Collapse
|
4
|
Miller HE, Kearney E, Nieto-Castañón A, Falsini R, Abur D, Acosta A, Chao SC, Dahl KL, Franken M, Heller Murray ES, Mollaei F, Niziolek CA, Parrell B, Perrachione T, Smith DJ, Stepp CE, Tomassi N, Guenther FH. Do Not Cut Off Your Tail: A Mega-Analysis of Responses to Auditory Perturbation Experiments. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2023; 66:4315-4331. [PMID: 37850867 PMCID: PMC10715843 DOI: 10.1044/2023_jslhr-23-00315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 08/04/2023] [Accepted: 08/06/2023] [Indexed: 10/19/2023]
Abstract
PURPOSE The practice of removing "following" responses from speech perturbation analyses is increasingly common, despite no clear evidence as to whether these responses represent a unique response type. This study aimed to determine if the distribution of responses to auditory perturbation paradigms represents a bimodal distribution, consisting of two distinct response types, or a unimodal distribution. METHOD This mega-analysis pooled data from 22 previous studies to examine the distribution and magnitude of responses to auditory perturbations across four tasks: adaptive pitch, adaptive formant, reflexive pitch, and reflexive formant. Data included at least 150 unique participants for each task, with studies comprising younger adult, older adult, and Parkinson's disease populations. A Silverman's unimodality test followed by a smoothed bootstrap resampling technique was performed for each task to evaluate the number of modes in each distribution. Wilcoxon signed-ranks tests were also performed for each distribution to confirm significant compensation in response to the perturbation. RESULTS Modality analyses were not significant (p > .05) for any group or task, indicating unimodal distributions. Our analyses also confirmed compensatory reflexive responses to pitch and formant perturbations across all groups, as well as adaptive responses to sustained formant perturbations. However, analyses of sustained pitch perturbations only revealed evidence of adaptation in studies with younger adults. CONCLUSION The demonstration of a clear unimodal distribution across all tasks suggests that following responses do not represent a distinct response pattern, but rather the tail of a unimodal distribution. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.24282676.
Collapse
Affiliation(s)
- Hilary E. Miller
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Elaine Kearney
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | | | - Riccardo Falsini
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Defne Abur
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Alexander Acosta
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Sara-Ching Chao
- College of Health Solutions, Arizona State University, Tempe
| | - Kimberly L. Dahl
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Matthias Franken
- Department of Psychology, McGill University, Montréal, Québec, Canada
| | | | - Fatemeh Mollaei
- School of Psychology and Clinical Language Sciences, University of Reading, England
| | - Caroline A. Niziolek
- Department of Communication Sciences and Disorders, University of Wisconsin–Madison
| | - Benjamin Parrell
- Department of Communication Sciences and Disorders, University of Wisconsin–Madison
| | - Tyler Perrachione
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Dante J. Smith
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Cara E. Stepp
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Nicole Tomassi
- Graduate Program for Neuroscience, Boston University, MA
| | - Frank H. Guenther
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| |
Collapse
|
5
|
Kim KS, Gaines JL, Parrell B, Ramanarayanan V, Nagarajan SS, Houde JF. Mechanisms of sensorimotor adaptation in a hierarchical state feedback control model of speech. PLoS Comput Biol 2023; 19:e1011244. [PMID: 37506120 PMCID: PMC10434967 DOI: 10.1371/journal.pcbi.1011244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 08/17/2023] [Accepted: 06/06/2023] [Indexed: 07/30/2023] Open
Abstract
Upon perceiving sensory errors during movements, the human sensorimotor system updates future movements to compensate for the errors, a phenomenon called sensorimotor adaptation. One component of this adaptation is thought to be driven by sensory prediction errors-discrepancies between predicted and actual sensory feedback. However, the mechanisms by which prediction errors drive adaptation remain unclear. Here, auditory prediction error-based mechanisms involved in speech auditory-motor adaptation were examined via the feedback aware control of tasks in speech (FACTS) model. Consistent with theoretical perspectives in both non-speech and speech motor control, the hierarchical architecture of FACTS relies on both the higher-level task (vocal tract constrictions) as well as lower-level articulatory state representations. Importantly, FACTS also computes sensory prediction errors as a part of its state feedback control mechanism, a well-established framework in the field of motor control. We explored potential adaptation mechanisms and found that adaptive behavior was present only when prediction errors updated the articulatory-to-task state transformation. In contrast, designs in which prediction errors updated forward sensory prediction models alone did not generate adaptation. Thus, FACTS demonstrated that 1) prediction errors can drive adaptation through task-level updates, and 2) adaptation is likely driven by updates to task-level control rather than (only) to forward predictive models. Additionally, simulating adaptation with FACTS generated a number of important hypotheses regarding previously reported phenomena such as identifying the source(s) of incomplete adaptation and driving factor(s) for changes in the second formant frequency during adaptation to the first formant perturbation. The proposed model design paves the way for a hierarchical state feedback control framework to be examined in the context of sensorimotor adaptation in both speech and non-speech effector systems.
Collapse
Affiliation(s)
- Kwang S. Kim
- Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Jessica L. Gaines
- Graduate Program in Bioengineering, University of California Berkeley-University of California San Francisco, San Francisco, California, United States of America
| | - Benjamin Parrell
- Department of Communication Sciences and Disorders, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Vikram Ramanarayanan
- Department of Otolaryngology-Head and Neck Surgery, University of California San Francisco, San Francisco, California, United States of America
- Modality.AI, San Francisco, California, United States of America
| | - Srikantan S. Nagarajan
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States of America
| | - John F. Houde
- Department of Otolaryngology-Head and Neck Surgery, University of California San Francisco, San Francisco, California, United States of America
| |
Collapse
|
6
|
Chao SC, Daliri A. Effects of Gradual and Sudden Introduction of Perturbations on Adaptive Responses to Formant-Shift and Formant-Clamp Perturbations. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2023; 66:1588-1599. [PMID: 37059081 PMCID: PMC10457088 DOI: 10.1044/2023_jslhr-21-00435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/30/2022] [Accepted: 01/31/2023] [Indexed: 05/11/2023]
Abstract
PURPOSE When the speech motor system encounters errors, it generates adaptive responses to compensate for the errors. Unlike errors induced by formant-shift perturbations, errors induced by formant-clamp perturbations do not correspond with the speaker's speech (i.e., degraded motor-to-auditory correspondence). We previously showed that adaptive responses to formant-clamp perturbations are smaller than responses to formant-shift perturbations when perturbations are introduced gradually. This study examined responses to formant-clamp and formant-shift perturbations when perturbations are introduced suddenly. METHOD One group of participants (n = 30) experienced gradually introduced formant-clamp and formant-shift perturbations, and another group (n = 30) experienced suddenly introduced formant-clamp and formant-shift perturbations. We designed the perturbations based on participant-specific vowel configurations such that a participant's first and second formants of /ɛ/ were perturbed toward their /æ/. To estimate adaptive responses, we measured formant changes (0-100 ms of the vowel) in response to the formant perturbations. RESULTS We found that (a) the difference between responses to formant-clamp and formant-shift perturbations was smaller when the perturbations were introduced suddenly and (b) responses to suddenly introduced (but not gradually introduced) formant-shift perturbations positively correlated with responses to formant-clamp perturbations. CONCLUSIONS These results showed that the speech motor system responds to errors induced by formant-shift and formant-clamp perturbations more differently when perturbations are introduced gradually than suddenly. Overall, the quality of errors (formant-shift vs. formant-clamp) and the manner of introducing errors (gradually vs. suddenly) modulate the speech motor system's evaluations of and responses to errors. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.22406422.
Collapse
Affiliation(s)
- Sara-Ching Chao
- College of Health Solutions, Arizona State University, Tempe
| | - Ayoub Daliri
- College of Health Solutions, Arizona State University, Tempe
| |
Collapse
|
7
|
Tang DL, Parrell B, Niziolek CA. Movement variability can be modulated in speech production. J Neurophysiol 2022; 128:1469-1482. [PMID: 36350054 PMCID: PMC9705022 DOI: 10.1152/jn.00095.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 10/19/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022] Open
Abstract
Although movement variability is often attributed to unwanted noise in the motor system, recent work has demonstrated that variability may be actively controlled. To date, research on regulation of motor variability has relied on relatively simple, laboratory-specific reaching tasks. It is not clear how these results translate to complex, well-practiced tasks. Here, we test how variability is regulated during speech production, a complex, highly overpracticed, and natural motor behavior that relies on auditory and somatosensory feedback. Specifically, in a series of four experiments, we assessed the effects of auditory feedback manipulations that modulate perceived speech variability, shifting every production either toward (inward pushing) or away from (outward pushing) the center of the distribution for each vowel. Participants exposed to the inward-pushing perturbation (experiment 1) increased produced variability while the perturbation was applied as well as after it was removed. Unexpectedly, the outward-pushing perturbation (experiment 2) also increased produced variability during exposure, but variability returned to near-baseline levels when the perturbation was removed. Outward-pushing perturbations failed to reduce participants' produced variability both with larger perturbation magnitude (experiment 3) and after their variability had increased above baseline levels as a result of the inward-pushing perturbation (experiment 4). Simulations of the applied perturbations using a state-space model of motor behavior suggest that the increases in produced variability in response to the two types of perturbations may arise through distinct mechanisms. Together, these results suggest that motor variability is actively monitored and can be modulated even in complex and well-practiced behaviors such as speech.NEW & NOTEWORTHY By implementing a novel auditory feedback perturbation that modulates participants' perceived trial-to-trial variability without affecting their overall mean behavior, we show that variability in the speech motor system can be modulated. By assaying speech production, we expand our current understanding of variability to a well-practiced, complex behavior outside of the limb control system. Our results additionally highlight the need to incorporate the active control of variability in models of speech motor control.
Collapse
Affiliation(s)
- Ding-Lan Tang
- Department of Communication Sciences and Disorders, University of Wisconsin-Madison, Madison, Wisconsin
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Benjamin Parrell
- Department of Communication Sciences and Disorders, University of Wisconsin-Madison, Madison, Wisconsin
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Caroline A Niziolek
- Department of Communication Sciences and Disorders, University of Wisconsin-Madison, Madison, Wisconsin
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin
| |
Collapse
|
8
|
Kearney E, Nieto-Castañón A, Falsini R, Daliri A, Heller Murray ES, Smith DJ, Guenther FH. Quantitatively characterizing reflexive responses to pitch perturbations. Front Hum Neurosci 2022; 16:929687. [PMID: 36405080 PMCID: PMC9666385 DOI: 10.3389/fnhum.2022.929687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022] Open
Abstract
Background Reflexive pitch perturbation experiments are commonly used to investigate the neural mechanisms underlying vocal motor control. In these experiments, the fundamental frequency–the acoustic correlate of pitch–of a speech signal is shifted unexpectedly and played back to the speaker via headphones in near real-time. In response to the shift, speakers increase or decrease their fundamental frequency in the direction opposing the shift so that their perceived pitch is closer to what they intended. The goal of the current work is to develop a quantitative model of responses to reflexive perturbations that can be interpreted in terms of the physiological mechanisms underlying the response and that captures both group-mean data and individual subject responses. Methods A model framework was established that allowed the specification of several models based on Proportional-Integral-Derivative and State-Space/Directions Into Velocities of Articulators (DIVA) model classes. The performance of 19 models was compared in fitting experimental data from two published studies. The models were evaluated in terms of their ability to capture both population-level responses and individual differences in sensorimotor control processes. Results A three-parameter DIVA model performed best when fitting group-mean data from both studies; this model is equivalent to a single-rate state-space model and a first-order low pass filter model. The same model also provided stable estimates of parameters across samples from individual subject data and performed among the best models to differentiate between subjects. The three parameters correspond to gains in the auditory feedback controller’s response to a perceived error, the delay of this response, and the gain of the somatosensory feedback controller’s “resistance” to this correction. Excellent fits were also obtained from a four-parameter model with an additional auditory velocity error term; this model was better able to capture multi-component reflexive responses seen in some individual subjects. Conclusion Our results demonstrate the stereotyped nature of an individual’s responses to pitch perturbations. Further, we identified a model that captures population responses to pitch perturbations and characterizes individual differences in a stable manner with parameters that relate to underlying motor control capabilities. Future work will evaluate the model in characterizing responses from individuals with communication disorders.
Collapse
Affiliation(s)
- Elaine Kearney
- Department of Speech, Language, and Hearing Sciences, Boston University, Boston, MA, United States
- *Correspondence: Elaine Kearney,
| | - Alfonso Nieto-Castañón
- Department of Speech, Language, and Hearing Sciences, Boston University, Boston, MA, United States
- The McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Riccardo Falsini
- Department of Speech, Language, and Hearing Sciences, Boston University, Boston, MA, United States
| | - Ayoub Daliri
- College of Health Solutions, Arizona State University, Tempe, AZ, United States
| | | | - Dante J. Smith
- Gradutate Program for Neuroscience, Boston University, Boston, MA, United States
| | - Frank H. Guenther
- Department of Speech, Language, and Hearing Sciences, Boston University, Boston, MA, United States
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, United States
| |
Collapse
|