What Is Left Is Right

2009 ◽  
Vol 14 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Kenneth Hugdahl ◽  
René Westerhausen
Keyword(s):  
Speech Processing ◽  
Information Transfer ◽  
Hemispheric Asymmetry ◽  
Functional Neuroimaging ◽  
Gray Matter Volume ◽  
Functional Anatomy ◽  
Posterior Part ◽  
Functional Asymmetry ◽  
Planum Temporale ◽  
Evolution Of Speech

The present paper is based on a talk on hemispheric asymmetry given by Kenneth Hugdahl at the Xth European Congress of Psychology, Praha July 2007. Here, we propose that hemispheric asymmetry evolved because of a left hemisphere speech processing specialization. The evolution of speech and the need for air-based communication necessitated division of labor between the hemispheres in order to avoid having duplicate copies in both hemispheres that would increase processing redundancy. It is argued that the neuronal basis of this labor division is the structural asymmetry observed in the peri-Sylvian region in the posterior part of the temporal lobe, with a left larger than right planum temporale area. This is the only example where a structural, or anatomical, asymmetry matches a corresponding functional asymmetry. The increase in gray matter volume in the left planum temporale area corresponds to a functional asymmetry of speech processing, as indexed from both behavioral, dichotic listening, and functional neuroimaging studies. The functional anatomy of the corpus callosum also supports such a view, with regional specificity of information transfer between the hemispheres.

Auditory–Articulatory Neural Alignment between Listener and Speaker during Verbal Communication

2019 ◽  
Vol 30 (3) ◽  
pp. 942-951 ◽  
Author(s):  
Lanfang Liu ◽  
Yuxuan Zhang ◽  
Qi Zhou ◽  
Douglas D Garrett ◽  
Chunming Lu ◽  
...  
Keyword(s):  
Speech Processing ◽  
Auditory Processing ◽  
Information Transfer ◽  
Temporal Cortex ◽  
Real Life ◽  
Hierarchical Organization ◽  
Speech Comprehension ◽  
Level Information ◽  
Motor Information ◽  
High Level

Abstract Whether auditory processing of speech relies on reference to the articulatory motor information of speaker remains elusive. Here, we addressed this issue under a two-brain framework. Functional magnetic resonance imaging was applied to record the brain activities of speakers when telling real-life stories and later of listeners when listening to the audio recordings of these stories. Based on between-brain seed-to-voxel correlation analyses, we revealed that neural dynamics in listeners’ auditory temporal cortex are temporally coupled with the dynamics in the speaker’s larynx/phonation area. Moreover, the coupling response in listener’s left auditory temporal cortex follows the hierarchical organization for speech processing, with response lags in A1+, STG/STS, and MTG increasing linearly. Further, listeners showing greater coupling responses understand the speech better. When comprehension fails, such interbrain auditory-articulation coupling vanishes substantially. These findings suggest that a listener’s auditory system and a speaker’s articulatory system are inherently aligned during naturalistic verbal interaction, and such alignment is associated with high-level information transfer from the speaker to the listener. Our study provides reliable evidence supporting that references to the articulatory motor information of speaker facilitate speech comprehension under a naturalistic scene.

scholarly journals A comparison of sensory-motor activity during speech in first and second languages

2011 ◽  
Vol 106 (1) ◽  
pp. 470-478 ◽  
Author(s):  
Anna J. Simmonds ◽  
Richard J. S. Wise ◽  
Novraj S. Dhanjal ◽  
Robert Leech
Keyword(s):  
Language Learning ◽  
Sensory Feedback ◽  
Functional Neuroimaging ◽  
Association Cortex ◽  
Planum Temporale ◽  
Second Languages ◽  
Somatosensory Cortices ◽  
Sensory Motor ◽  
Neuroimaging Study ◽  
Overt Speech

A foreign language (L2) learned after childhood results in an accent. This functional neuroimaging study investigated speech in L2 as a sensory-motor skill. The hypothesis was that there would be an altered response in auditory and somatosensory association cortex, specifically the planum temporale and parietal operculum, respectively, when speaking in L2 relative to L1, independent of rate of speaking. These regions were selected for three reasons. First, an influential computational model proposes that these cortices integrate predictive feedforward and postarticulatory sensory feedback signals during articulation. Second, these adjacent regions (known as Spt) have been identified as a “sensory-motor interface” for speech production. Third, probabilistic anatomical atlases exist for these regions, to ensure the analyses are confined to sensory-motor differences between L2 and L1. The study used functional magnetic resonance imaging (fMRI), and participants produced connected overt speech. The first hypothesis was that there would be greater activity in the planum temporale and the parietal operculum when subjects spoke in L2 compared with L1, one interpretation being that there is less efficient postarticulatory sensory monitoring when speaking in the less familiar L2. The second hypothesis was that this effect would be observed in both cerebral hemispheres. Although Spt is considered to be left-lateralized, this is based on studies of covert speech, whereas overt speech is accompanied by sensory feedback to bilateral auditory and somatosensory cortices. Both hypotheses were confirmed by the results. These findings provide the basis for future investigations of sensory-motor aspects of language learning using serial fMRI studies.

scholarly journals The Inferior Frontal Gyrus and Phonological Processing: An Investigation using rTMS

2004 ◽  
Vol 16 (2) ◽  
pp. 289-300 ◽  
Author(s):  
Philip Nixon ◽  
Jenia Lazarova ◽  
Iona Hodinott-Hill ◽  
Patricia Gough ◽  
Richard Passingham
Keyword(s):  
Working Memory ◽  
Phonological Processing ◽  
Functional Neuroimaging ◽  
Inferior Frontal Gyrus ◽  
Posterior Part ◽  
Verbal Working Memory ◽  
Normal Operation ◽  
Matching Task ◽  
Language Areas

Repetitive transcranial magnetic stimulation (rTMS) offers a powerful new technique for investigating the distinct contributions of the cortical language areas. We have used this method to examine the role of the left inferior frontal gyrus (IFG) in phonological processing and verbal working memory. Functional neuroimaging studies have implicated the posterior part of the left IFG in both phonological decision making and subvocal rehearsal mechanisms, but imaging is a correlational method and it is therefore necessary to determine whether this region is essential for such processes. In this paper we present the results of two experiments in which rTMS was applied over the frontal operculum while subjects performed a delayed phonological matching task. We compared the effects of disrupting this area either during the delay (memory) phase or at the response (decision) phase of the task. Delivered at a time when subjects were required to remember the sound of a visually presented word, rTMS impaired the accuracy with which they subsequently performed the task. However, when delivered later in the trial, as the subjects compared the remembered word with a given pseudoword, rTMS did not impair accuracy. Performance by the same subjects on a control task that required the processing of nonverbal visual stimuli was unaffected by the rTMS. Similarly, performance on both tasks was unaffected by rTMS delivered over a more anterior site (pars triangularis). We conclude that the opercular region of the IFG is necessary for the normal operation of phonologically based working memory mechanisms. Furthermore, this study shows that rTMS can shed further light on the precise role of cortical language areas in humans.

Functional asymmetry in schizophrenic patients during auditory speech processing

2001 ◽  
Vol 52 (1-2) ◽  
pp. 69-78 ◽  
Author(s):  
B Mohr ◽  
S Heim ◽  
F Pulvermüller ◽  
B Rockstroh
Keyword(s):  
Speech Processing ◽  
Functional Asymmetry ◽  
Auditory Speech ◽  
Schizophrenic Patients

scholarly journals Uncovering the functional anatomy of the human insula during speech

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Oscar Woolnough ◽  
Kiefer James Forseth ◽  
Patrick Sarahan Rollo ◽  
Nitin Tandon
Keyword(s):  
Functional Neuroimaging ◽  
Functional Anatomy ◽  
Insular Cortex ◽  
Superior Temporal Gyrus ◽  
Single Word ◽  
Orofacial Movements ◽  
Frontal Operculum ◽  
Posterior Insula ◽  
Series Of Experiments ◽  
Intracranial Electrodes

The contribution of insular cortex to speech production remains unclear and controversial given diverse findings from functional neuroimaging and lesional data. To create a precise spatiotemporal map of insular activity, we performed a series of experiments: single-word articulations of varying complexity, non-speech orofacial movements and speech listening, in a cohort of 27 patients implanted with penetrating intracranial electrodes. The posterior insula was robustly active bilaterally, but after the onset of articulation, during listening to speech and during production of non-speech mouth movements. Preceding articulation there was very sparse activity, localized primarily to the frontal operculum rather than the insula. Posterior insular was active coincident with superior temporal gyrus but was more active for self-generated speech than external speech, the opposite of the superior temporal gyrus. These findings support the conclusion that the insula does not serve pre-articulatory preparatory roles.

Magnetic resonance imaging markers of suicide attempt and suicide risk in adolescents

CNS Spectrums ◽  
2015 ◽  
Vol 20 (4) ◽  
pp. 355-358 ◽  
Author(s):  
Petra C. Martin ◽  
Thomas J. Zimmer ◽  
Lisa A. Pan
Keyword(s):  
Suicide Attempt ◽  
Psychosocial Development ◽  
Functional Neuroimaging ◽  
Gray Matter Volume ◽  
The United States ◽  
Anterior Cingulate ◽  
Prefrontal Cortical ◽  
History Of ◽  
Brain Changes ◽  
Cortical Regions

More than 36,000 people in the United States die from suicide annually, and suicide is the third leading cause of death in adolescence. Adolescence is a time of high risk for suicidal behavior, as well as a time that intervention and treatment may have the greatest impact because of structural brain changes and significant psychosocial development during this period. Functional and structural neuroimaging studies in adults who have attempted suicide suggest distinct gray matter volume abnormalities in cortical regions, as well as prefrontal cortical and dorsal anterior cingulate gyrus neural circuitry differences compared with affective and healthy adult controls. Recent functional neuroimaging studies in adolescents with a history of suicide attempt suggest differences in the attention and salience networks compared with adolescents with depression and no history of suicide attempt and healthy controls when viewing angry faces. In contrast, no abnormalities are seen in these areas in the absence of emotional stimuli. These networks may represent promising targets for future neuroimaging studies to identify markers of risk for future suicide attempt in adolescents.

scholarly journals Neurosurgery for schizophrenia: an update on pathophysiology and a novel therapeutic target

2016 ◽  
Vol 124 (4) ◽  
pp. 917-928 ◽  
Author(s):  
Charles B. Mikell ◽  
Saurabh Sinha ◽  
Sameer A. Sheth
Keyword(s):  
Functional Neuroimaging ◽  
Treatment Options ◽  
Functional Anatomy ◽  
Clinical Problem ◽  
Psychotic Symptoms ◽  
Ethical Considerations ◽  
Vulnerable Patients ◽  
Glutamatergic Signaling ◽  
Deep Brain ◽  
Made In

The main objectives of this review were to provide an update on the progress made in understanding specific circuit abnormalities leading to psychotic symptoms in schizophrenia and to propose rational targets for therapeutic deep brain stimulation (DBS). Refractory schizophrenia remains a major unsolved clinical problem, with 10%–30% of patients not responding to standard treatment options. Progress made over the last decade was analyzed through reviewing structural and functional neuroimaging studies in humans, along with studies of animal models of schizophrenia. The authors reviewed theories implicating dysfunction in dopaminergic and glutamatergic signaling in the pathophysiology of the disorder, paying particular attention to neurosurgically relevant nodes in the circuit. In this context, the authors focused on an important pathological circuit involving the associative striatum, anterior hippocampus, and ventral striatum, and discuss the possibility of targeting these nodes for therapeutic neuromodulation with DBS. Finally, the authors examined ethical considerations in the treatment of these vulnerable patients. The functional anatomy of neural circuits relevant to schizophrenia remains of great interest to neurosurgeons and psychiatrists and lends itself to the development of specific targets for neuromodulation. Ongoing progress in the understanding of these structures will be critical to the development of potential neurosurgical treatments of schizophrenia.

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