Temporal dynamics of the speech readiness potential, and its use in a neural decoder of speech-motor intention

Abstract Holding a conversation means that speech must be started, maintained, and stopped continuously. The brain networks that underlie these aspects of speech motor control remain poorly understood. Here we collected functional magnetic resonance imaging (fMRI) data while participants produced normal and fast rate speech in response to sequences of visually presented objects. We took a non-conventional approach to fMRI data analysis that allowed us to study speech motor behavior as it unfolded over time. To this end, whole-brain fMRI signals were extracted in stimulus-locked epochs using slice-based fMRI. These data were then subjected to group independent component analysis to discover spatially independent networks that were associated with different temporal activation profiles. The results revealed two basic brain networks with different temporal dynamics: a cortical network that was activated continuously during speech production, and a second cortico-subcortical network that increased in activity during the initiation and suppression of speech production. Additional analyses explored whether key areas involved in motor suppression such as the right inferior frontal gyrus, sub-thalamic nucleus and pre-supplementary motor area provide first-order signals to stop speech. The results reveal for the first time the brain networks associated with the initiation, maintenance, and suppression of speech motor behavior.

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Predicted sensory consequences of voluntary actions modulate amplitude and temporal dynamics of preceding readiness potentials

10.1101/101402 ◽

2017 ◽

Author(s):

Daniel Reznik ◽

Shiri Simon ◽

Roy Mukamel

Keyword(s):

Motor Activity ◽

Early Phase ◽

Healthy Subjects ◽

Temporal Dynamics ◽

Readiness Potential ◽

Button Press ◽

Eeg Signal ◽

Eeg Data ◽

Readiness Potentials ◽

Neural Signature

AbstractSelf-generated, voluntary actions, are preceded by a slow negativity in the scalp electroencephalography (EEG) signal recorded from frontal regions (termed ‘readiness potential’; RP). This signal, and its lateralized subcomponent (LRP), is mainly regarded as preparatory motor activity associated with the forthcoming motor act. However, it is not clear whether this neural signature is associated with preparatory motor activity, expectation of its associated sensory consequences, or both. Here we recorded EEG data from 12 healthy subjects while they performed self-paced button presses with their right index and middle fingers. In one condition (motor+sound) these button-presses triggered a sound while in another (motor-only) they did not. Additionally, subjects passively listened to sounds delivered in expected timings (sound-only). We found that the RP amplitude (locked to time of button press) was significantly more negative in the motor+sound compared with motor-only conditions starting ~1.4 seconds prior to button press. Importantly, no signal negativity was observed prior to expected sound delivery in the sound-only condition. Thus, the differences in RP amplitude between motor+sound and motor-only conditions are beyond differences in mere expectation of a forthcoming auditory sound. No significant differences between the two conditions were obtained in the LRP component. Our results suggest that expected auditory consequences are encoded in the early phase of the RP preceding the voluntary actions that generate them.

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Cognitive Load Affects Speech Motor Performance Differently in Older and Younger Adults

Journal of Speech Language and Hearing Research ◽

10.1044/2018_jslhr-s-17-0222 ◽

2019 ◽

Vol 62 (5) ◽

pp. 1258-1277 ◽

Cited By ~ 1

Author(s):

Megan K. MacPherson

Keyword(s):

Older Adults ◽

Cognitive Load ◽

Motor Performance ◽

Age Groups ◽

Incongruent Condition ◽

Sentence Production ◽

Movement Duration ◽

Production Task ◽

Younger Adults ◽

Speech Motor

PurposeThe aim of this study was to determine the impact of cognitive load imposed by a speech production task on the speech motor performance of healthy older and younger adults. Response inhibition, selective attention, and working memory were the primary cognitive processes of interest.MethodTwelve healthy older and 12 healthy younger adults produced multiple repetitions of 4 sentences containing an embedded Stroop task in 2 cognitive load conditions: congruent and incongruent. The incongruent condition, which required participants to suppress orthographic information to say the font colors in which color words were written, represented an increase in cognitive load relative to the congruent condition in which word text and font color matched. Kinematic measures of articulatory coordination variability and movement duration as well as a behavioral measure of sentence production accuracy were compared between groups and conditions and across 3 sentence segments (pre-, during-, and post-Stroop).ResultsIncreased cognitive load in the incongruent condition was associated with increased articulatory coordination variability and movement duration, compared to the congruent Stroop condition, for both age groups. Overall, the effect of increased cognitive load was greater for older adults than younger adults and was greatest in the portion of the sentence in which cognitive load was manipulated (during-Stroop), followed by the pre-Stroop segment. Sentence production accuracy was reduced for older adults in the incongruent condition.ConclusionsIncreased cognitive load involving response inhibition, selective attention, and working memory processes within a speech production task disrupted both the stability and timing with which speech was produced by both age groups. Older adults' speech motor performance may have been more affected due to age-related changes in cognitive and motoric functions that result in altered motor cognition.

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What Does It Mean to Be Social? Defining the Social Landscape for Children With Childhood Apraxia of Speech

Perspectives of the ASHA Special Interest Groups ◽

10.1044/2020_persp-19-00116 ◽

2020 ◽

Vol 5 (4) ◽

pp. 843-852 ◽

Cited By ~ 1

Author(s):

Nancy Tarshis ◽

Michelle Garcia Winner ◽

Pamela Crooke

Keyword(s):

Social Development ◽

Social Goals ◽

Apraxia Of Speech ◽

Childhood Apraxia Of Speech ◽

Social Competencies ◽

The Social ◽

Social Landscape ◽

Communication Challenges ◽

Primary Focus ◽

Speech Motor

Purpose What does it mean to be social? In addition, how is that different from behaving socially appropriately? The purpose of this clinical focus article is to tackle these two questions along with taking a deeper look into how communication challenges in childhood apraxia of speech impact social competencies for young children. Through the lens of early social development and social competency, this clinical focus article will explore how speech motor challenges can impact social development and what happens when young learners miss early opportunities to grow socially. While not the primary focus, the clinical focus article will touch upon lingering issues for individuals diagnosed with childhood apraxia of speech as they enter the school-aged years. Conclusion Finally, it will address some foundational aspects of intervention and offer ideas and suggestions for structuring therapy to address both speech and social goals.

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Syntax, Stress Response, and Speech Motor Control

Perspectives on Fluency and Fluency Disorders ◽

10.1044/ffd17.2.25 ◽

2007 ◽

Vol 17 (2) ◽

pp. 25-26

Author(s):

Jennifer Kleinow

Keyword(s):

Motor Control ◽

Stress Response ◽

Speech Motor Control ◽

Speech Motor

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Do Sentence Length and Syntactic Complexity Influence Speech Motor Control?

ASHA Leader ◽

10.1044/leader.rib3.18072013.33 ◽

2013 ◽

Vol 18 (7) ◽

pp. 33-34

Keyword(s):

Motor Control ◽

Sentence Length ◽

Speech Motor Control ◽

Syntactic Complexity ◽

Speech Motor

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Physiologic Studies Provide New Perspectives on Early Speech Development

Perspectives on Speech Science and Orofacial Disorders ◽

10.1044/ssod20.2.29 ◽

2010 ◽

Vol 20 (2) ◽

pp. 29-36

Author(s):

Erin M. Wilson ◽

Ignatius S. B. Nip

Keyword(s):

Motor Control ◽

Motor Development ◽

Motion Tracking ◽

Speech Development ◽

Speech Motor Control ◽

Therapeutic Approaches ◽

Facial Motion ◽

Disordered Speech ◽

Speech Motor ◽

Physiologic Data

Abstract Although certain speech development milestones are readily observable, the developmental course of speech motor control is largely unknown. However, recent advances in facial motion tracking systems have been used to investigate articulator movements in children and the findings from these studies are being used to further our understanding of the physiologic basis of typical and disordered speech development. Physiologic work has revealed that the emergence of speech is highly dependent on the lack of flexibility in the early oromotor system. It also has been determined that the progression of speech motor development is non-linear, a finding that has motivated researchers to investigate how variables such as oromotor control, cognition, and linguistic factors affect speech development in the form of catalysts and constraints. Physiologic data are also being used to determine if non-speech oromotor behaviors play a role in the development of speech. This improved understanding of the physiology underlying speech, as well as the factors influencing its progression, helps inform our understanding of speech motor control in children with disordered speech and provide a framework for theory-driven therapeutic approaches to treatment.

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Nonlinear Spatio-Temporal Dynamics and Chaos in Semiconductors

10.1017/cbo9780511524615 ◽

2001 ◽

Cited By ~ 136

Author(s):

Eckehard Schöll

Keyword(s):

Temporal Dynamics ◽

Spatio Temporal

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Effects of Monetary Incentives on Task Switching

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000146 ◽

2012 ◽

Vol 59 (4) ◽

pp. 216-226 ◽

Cited By ~ 36

Author(s):

Thomas Kleinsorge ◽

Gerhard Rinkenauer

Keyword(s):

Task Switching ◽

Temporal Dynamics ◽

Reward Processing ◽

General Level ◽

Monetary Incentives ◽

Switch Costs ◽

Expectancy Effect ◽

Reward Expectancy ◽

Trial Basis

In two experiments, effects of incentives on task switching were investigated. Incentives were provided as a monetary bonus. In both experiments, the availability of a bonus varied on a trial-to-trial basis. The main difference between the experiments relates to the association of incentives to individual tasks. In Experiment 1, the association of incentives to individual tasks was fixed. Under these conditions, the effect of incentives was largely due to reward expectancy. Switch costs were reduced to statistical insignificance. This was true even with the task that was not associated with a bonus. In Experiment 2, there was a variable association of incentives to individual tasks. Under these conditions, the reward expectancy effect was bound to conditions with a well-established bonus-task association. In conditions in which the bonus-task association was not established in advance, enhanced performance of the bonus task was accompanied by performance decrements with the task that was not associated with a bonus. Reward expectancy affected mainly the general level of performance. The outcome of this study may also inform recently suggested neurobiological accounts about the temporal dynamics of reward processing.

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