Sound representation in higher language areas during language generation

How language is encoded by neural activity in the higher-level language areas of humans is still largely unknown. We investigated whether the electrophysiological activity of Broca’s area correlates with the sound of the utterances produced. During speech perception, the electric cortical activity of the auditory areas correlates with the sound envelope of the utterances. In our experiment, we compared the electrocorticogram recorded during awake neurosurgical operations in Broca’s area and in the dominant temporal lobe with the sound envelope of single words versus sentences read aloud or mentally by the patients. Our results indicate that the electrocorticogram correlates with the sound envelope of the utterances, starting before any sound is produced and even in the absence of speech, when the patient is reading mentally. No correlations were found when the electrocorticogram was recorded in the superior parietal gyrus, an area not directly involved in language generation, or in Broca’s area when the participants were executing a repetitive motor task, which did not include any linguistic content, with their dominant hand. The distribution of suprathreshold correlations across frequencies of cortical activities varied whether the sound envelope derived from words or sentences. Our results suggest the activity of language areas is organized by sound when language is generated before any utterance is produced or heard.

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Redefining the role of Broca’s area in speech

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1414491112 ◽

2015 ◽

Vol 112 (9) ◽

pp. 2871-2875 ◽

Cited By ~ 177

Author(s):

Adeen Flinker ◽

Anna Korzeniewska ◽

Avgusta Y. Shestyuk ◽

Piotr J. Franaszczuk ◽

Nina F. Dronkers ◽

...

Keyword(s):

Motor Cortex ◽

Neural Activity ◽

Large Scale ◽

Inferior Frontal Gyrus ◽

Temporal Cortex ◽

Word Production ◽

Broca’S Area ◽

Broca's Area ◽

Neurosurgical Patients

For over a century neuroscientists have debated the dynamics by which human cortical language networks allow words to be spoken. Although it is widely accepted that Broca’s area in the left inferior frontal gyrus plays an important role in this process, it was not possible, until recently, to detail the timing of its recruitment relative to other language areas, nor how it interacts with these areas during word production. Using direct cortical surface recordings in neurosurgical patients, we studied the evolution of activity in cortical neuronal populations, as well as the Granger causal interactions between them. We found that, during the cued production of words, a temporal cascade of neural activity proceeds from sensory representations of words in temporal cortex to their corresponding articulatory gestures in motor cortex. Broca’s area mediates this cascade through reciprocal interactions with temporal and frontal motor regions. Contrary to classic notions of the role of Broca’s area in speech, while motor cortex is activated during spoken responses, Broca’s area is surprisingly silent. Moreover, when novel strings of articulatory gestures must be produced in response to nonword stimuli, neural activity is enhanced in Broca’s area, but not in motor cortex. These unique data provide evidence that Broca’s area coordinates the transformation of information across large-scale cortical networks involved in spoken word production. In this role, Broca’s area formulates an appropriate articulatory code to be implemented by motor cortex.

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Facilitation and inhibition of syntactic processing by focal transcranial magnetic stimulation of Broca's area

Neuroscience Research ◽

10.1016/s0168-0102(00)81164-5 ◽

2000 ◽

Vol 38 ◽

pp. S53

Author(s):

K Sakai

Keyword(s):

Transcranial Magnetic Stimulation ◽

Magnetic Stimulation ◽

Syntactic Processing ◽

Broca’S Area ◽

Broca's Area ◽

Stimulation Of

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The „narrow faculty“ and Broca's area

Aktuelle Neurologie ◽

10.1055/s-0028-1086964 ◽

2008 ◽

Vol 35 (S 01) ◽

Author(s):

M Musso ◽

A Schneider ◽

C Büchel ◽

C Weiller

Keyword(s):

Broca’S Area ◽

Broca's Area

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Faculty Opinions recommendation of Encoding of human action in Broca's area.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1168491.630680 ◽

2009 ◽

Author(s):

Barbro B Johansson

Keyword(s):

Human Action ◽

Broca’S Area ◽

Broca's Area

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An Agent-Specific Stochastic Model of Generalized Reaching Task Difficulty

Applied Sciences ◽

10.3390/app11104330 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4330

Author(s):

Andrea Lucchese ◽

Salvatore Digiesi ◽

Kübra Akbaş ◽

Carlotta Mummolo

Keyword(s):

Stochastic Model ◽

Task Difficulty ◽

Motor Task ◽

Younger Adults ◽

Reaching Task ◽

Index Of Difficulty ◽

Young Subjects ◽

Aged Subjects ◽

Spatial Trajectories ◽

Repetitive Motor

The ability of an agent to accomplish a trajectory during a certain motor task depends on the fit between external (environment) and internal (agent) constraints, also known as affordance. A model of difficulty for a generalized reaching motor task is proposed as an affordance-related measure, as perceived by a specific agent for a given environment and task. By extending the information-based Index of Difficulty of a trajectory, a stochastic model of difficulty is formulated based on the observed variability of spatial trajectories executed by a given agent during a repetitive motor task. The model is tested on an experimental walking dataset available in the literature, where the repetitive stride movement of differently aged subjects (14 “old” subjects aged 50–73; 20 “young” subjects aged 21–37) at multiple speed conditions (comfortable, ~30% faster, ~30% slower) is analyzed. Reduced trajectory variability in older as compared to younger adults results in a higher Index of Difficulty (slower: +24%, p < 0.0125; faster: +38%, p < 0.002) which is interpreted in this context as reduced affordance. The model overcomes the limits of existing difficulty measures by capturing the stochastic dependency of task difficulty on a subject’s age and average speed. This model provides a benchmarking tool for motor performance in biomechanics and ergonomics applications.

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SURG-40. SURGICAL RESECTIONS IN BROCA’S AREA DO NOT LEAD TO BROCA’S APHASIA

Neuro-Oncology ◽

10.1093/neuonc/noaa215.886 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii212-ii212

Author(s):

John Andrews ◽

Nathan Cahn ◽

Benjamin Speidel ◽

Valerie Lu ◽

Mitchel Berger ◽

...

Keyword(s):

Inferior Frontal Gyrus ◽

Brain Surgery ◽

Broca’S Area ◽

Broca's Area ◽

Supramarginal Gyrus ◽

Broca's Aphasia ◽

Broca’S Aphasia ◽

Language Evaluations ◽

Lesion Symptom Mapping ◽

Normal Speech

Abstract Brodmann’s areas 44/45 of the inferior frontal gyrus (IFG), are the seat of Broca’s area. The Western Aphasia Battery is a commonly used language battery that diagnoses aphasias based on fluency, comprehension, naming and repetition. Broca’s aphasia is defined as low fluency (0-4/10), retained comprehension (4-10/10), and variable deficits in repetition (0-7.9/10) and naming (0-8/10). The purpose of this study was to find anatomic areas associated with Broca’s aphasia. Patients who underwent resective brain surgery in the dominant hemisphere were evaluated with standardized language batteries pre-op, POD 2, and 1-month post-op. The resection cavities were outlined to construct 3D-volumes of interest. These were aligned using an affine transformation to MNI brain space. A voxel-based lesion-symptom mapping (VLSM) algorithm determined areas associated with Broca’s aphasia when incorporated into a resection. Post-op MRIs were reviewed blindly and percent involvement of pars orbitalis, triangularis and opercularis was recorded. 287 patients had pre-op and POD 2 language evaluations and 178 had 1 month post-op language evaluation. 82/287 patients had IFG involvement in resections. Only 5/82 IFG resections led to Broca’s aphasia. 11/16 patients with Broca’s aphasia at POD 2 had no involvement of IFG in resection. 35% of IFG resections were associated with non-specific dysnomia and 36% were normal. By one-month, 76% of patients had normal speech. 80% of patients with Broca’s aphasia at POD 2 improved to normal speech at 1-month, with 20% improved to non-specific dysnomia. The most highly correlated (P< 0.005) anatomic areas with Broca’s aphasia were juxta-sylvian pre- and post-central gyrus extending to supramarginal gyrus. While Broca’s area resections were rarely associated with Broca’s aphasia, juxta-sylvian pre- and post-central gyri extending to the supramarginal gyrus were statistically associated with Broca’s type aphasia when resected. These results have implications for planning resective brain surgery in these presumed eloquent brain areas.

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