The neural basis of combinatory syntax and semantics

Science ◽  
2019 ◽  
Vol 366 (6461) ◽  
pp. 62-66 ◽  
Author(s):  
Liina Pylkkänen
Keyword(s):  
Syntactic Structure ◽  
Building Blocks ◽  
Brain Regions ◽  
System Research ◽  
Neural Basis ◽  
Signed Language ◽  
Show Evidence ◽  
Finite Set ◽  
Neurobiological Research ◽  
Natural Language Syntax

Human language allows us to create an infinitude of ideas from a finite set of basic building blocks. What is the neurobiology of this combinatory system? Research has begun to dissect the neural basis of natural language syntax and semantics by analyzing the basics of meaning composition, such as two-word phrases. This work has revealed a system of composition that involves rapidly peaking activity in the left anterior temporal lobe and later engagement of the medial prefrontal cortex. Both brain regions show evidence of shared processing between comprehension and production, as well as between spoken and signed language. Both appear to compute meaning, not syntactic structure. This Review discusses how language builds meaning and lays out directions for future neurobiological research on the combinatory system.

scholarly journals Syntactic representations in the human brain: beyond effort-based metrics

2020 ◽  
Author(s):  
Aniketh Janardhan Reddy ◽  
Leila Wehbe
Keyword(s):  
Language Processing ◽  
Syntactic Structure ◽  
Brain Activity ◽  
Brain Regions ◽  
Syntactic Processing ◽  
Language System ◽  
Language Studies ◽  
Syntactic Information ◽  
Show Evidence ◽  
The Brain

AbstractWe are far from having a complete mechanistic understanding of the brain computations involved in language processing and of the role that syntax plays in those computations. Most language studies do not computationally model syntactic structure, and most studies that do model syntactic processing use effort-based metrics. These metrics capture the effort needed to process the syntactic information given by every word [9, 10, 25]. They can reveal where in the brain syntactic processing occurs, but not what features of syntax are processed by different brain regions. Here, we move beyond effort-based metrics and propose explicit features capturing the syntactic structure that is incrementally built while a sentence is being read. Using these features and functional Magnetic Resonance Imaging (fMRI) recordings of participants reading a natural text, we study the brain representation of syntax. We find that our syntactic structure-based features are better than effort-based metrics at predicting brain activity in various parts of the language system. We show evidence of the brain representation of complex syntactic information such as phrase and clause structures. We see that regions well-predicted by syntactic features are distributed in the language system and are not distinguishable from those processing semantics. Our results call for a shift in the approach used for studying syntactic processing.

A tribute to Johann Gottlieb Burckhardt-Heussler (1836–1907), the pioneer of psychosurgery

2016 ◽  
Vol 33 (S1) ◽  
pp. S553-S553 ◽  
Author(s):  
M. Arts ◽  
P. Michielsen ◽  
S. Petrykiv ◽  
L. de Jonge
Keyword(s):  
Significant Contribution ◽  
Psychiatric Patients ◽  
Brain Regions ◽  
Medical Community ◽  
Psychiatric Illnesses ◽  
Scientific Papers ◽  
Show Evidence ◽  
Competing Interest ◽  
Chronic Psychiatric Patients ◽  
Deep Brain

IntroductionJohann Gottlieb Burckhardt-Heussler was a Swiss psychiatrist, who pioneered controversial psychosurgical procedures. Burckhardt-Heussler extirpated various brain regions from six chronic psychiatric patients under his care. By removing cortical tissue he aimed to relieve the patients of symptoms, including agitation, rather than effect a cure.ObjectivesTo present the scientific papers of Johann Gottlieb Burckhardt-Heussler on psychosurgery.AimsTo review available literature and to show evidence that Burckhardt-Heussler made a significant contribution to the development of psychosurgery.MethodsA biography and private papers are presented and discussed, followed by a literature review.ResultsThe theoretical basis of Burckhardt-Heussler's psychosurgical procedure was influenced by the zeitgeist and based on his belief that psychiatric illnesses were the result of specific brain lesions. His findings were ignored by scientists to make them disappear into the mists of time, while the details of his experiments became murky. Decades later, it was the American neurologist Walter Freeman II, performing prefrontal lobotomies since 1936, who found it inconceivable that the medical community had forgotten Burckhardt-Heussler and who conceded that he was familiar with, and probably even influenced by, Burckhardt's work.ConclusionIt is partly thanks to Burckhardt-Heussler's pioneering work that modern psychosurgery has gradually evolved from irreversible ablation to reversible stimulation techniques, including deep brain stimulation.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Dissociation between Frontal and Temporal-Parietal Contributions to Connected Speech in Acute Stroke

2019 ◽  
Author(s):  
Junhua Ding ◽  
Randi Martin ◽  
A. Cris Hamilton ◽  
Tatiana T. Schnur
Keyword(s):  
Acute Stroke ◽  
Syntactic Structure ◽  
Theoretical Models ◽  
Brain Regions ◽  
Lesion Size ◽  
Acute Stage ◽  
Chronic Stroke ◽  
Connected Speech ◽  
Left Hemisphere Stroke ◽  
Previous Identification

AbstractHumans are uniquely able to retrieve and combine words into syntactic structure to produce connected speech. Previous identification of focal brain regions necessary for production focused primarily on associations with the content produced by speakers with chronic stroke, where function may have shifted to other regions after reorganization occurred. Here, we relate patterns of brain damage with deficits to the content and structure of spontaneous connected speech in 52 speakers during the acute stage of a left hemisphere stroke. Multivariate lesion behavior mapping demonstrated that damage to temporal-parietal regions impacted the ability to retrieve words and produce them within increasingly complex combinations. Damage primarily to inferior frontal cortex affected the production of syntactically accurate structure. In contrast to previous work, functional-anatomical dissociations did not depend on lesion size likely because acute lesions were smaller than typically found in chronic stroke. These results are consistent with predictions from theoretical models based primarily on evidence from language comprehension and highlight the importance of investigating individual differences in brain-language relationships in speakers with acute stroke.

The Structural Language Network

2017 ◽  
Author(s):  
Angela D. Friederici ◽  
Noam Chomsky
Keyword(s):  
White Matter ◽  
Language Processing ◽  
Sentence Processing ◽  
Information Transfer ◽  
Right Hemisphere ◽  
Brain Regions ◽  
Neural Basis ◽  
Fiber Tracts ◽  
White Matter Fiber Tracts ◽  
The Right

An adequate description of the neural basis of language processing must consider the entire network both with respect to its structural white matter connections and the functional connectivities between the different brain regions as the information has to be sent between different language-related regions distributed across the temporal and frontal cortex. This chapter discusses the white matter fiber bundles that connect the language-relevant regions. The chapter is broken into three sections. In the first, we look at the white matter fiber tracts connecting the language-relevant regions in the frontal and temporal cortices; in the second, the ventral and dorsal pathways in the right hemisphere that connect temporal and frontal regions; and finally in the third, the two syntax-relevant and (at least) one semantic-relevant neuroanatomically-defined networks that sentence processing is based on. From this discussion, it becomes clear that online language processing requires information transfer via the long-range white matter fiber pathways that connect the language-relevant brain regions within each hemisphere and between hemispheres.

scholarly journals Understanding the Effects of General Anesthetics on Cortical Network Activity Using Ex Vivo Preparations

2019 ◽  
Vol 130 (6) ◽  
pp. 1049-1063 ◽  
Author(s):  
Logan J. Voss ◽  
Paul S. García ◽  
Harald Hentschke ◽  
Matthew I. Banks
Keyword(s):  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Brain Slices ◽  
Brain Regions ◽  
Cortical Network ◽  
Network Activity ◽  
Common Mechanism ◽  
General Anesthetics ◽  
Neural Basis

Abstract General anesthetics have been used to ablate consciousness during surgery for more than 150 yr. Despite significant advances in our understanding of their molecular-level pharmacologic effects, comparatively little is known about how anesthetics alter brain dynamics to cause unconsciousness. Consequently, while anesthesia practice is now routine and safe, there are many vagaries that remain unexplained. In this paper, the authors review the evidence that cortical network activity is particularly sensitive to general anesthetics, and suggest that disruption to communication in, and/or among, cortical brain regions is a common mechanism of anesthesia that ultimately produces loss of consciousness. The authors review data from acute brain slices and organotypic cultures showing that anesthetics with differing molecular mechanisms of action share in common the ability to impair neurophysiologic communication. While many questions remain, together, ex vivo and in vivo investigations suggest that a unified understanding of both clinical anesthesia and the neural basis of consciousness is attainable.

scholarly journals The neuroscience of Romeo and Juliet : an fMRI study of acting

2019 ◽  
Vol 6 (3) ◽  
pp. 181908 ◽  
Author(s):  
Steven Brown ◽  
Peter Cockett ◽  
Ye Yuan
Keyword(s):  
Brain Activity ◽  
Role Playing ◽  
Brain Regions ◽  
Multiple Roles ◽  
First Person ◽  
Neural Basis ◽  
Romeo And Juliet ◽  
Loss Of Self ◽  
Fmri Study ◽  
Mri Study

The current study represents a first attempt at examining the neural basis of dramatic acting. While all people play multiple roles in daily life—for example, ‘spouse' or ‘employee'—these roles are all facets of the ‘self' and thus of the first-person (1P) perspective. Compared to such everyday role playing, actors are required to portray other people and to adopt their gestures, emotions and behaviours. Consequently, actors must think and behave not as themselves but as the characters they are pretending to be. In other words, they have to assume a ‘fictional first-person' (Fic1P) perspective. In this functional MRI study, we sought to identify brain regions preferentially activated when actors adopt a Fic1P perspective during dramatic role playing. In the scanner, university-trained actors responded to a series of hypothetical questions from either their own 1P perspective or from that of Romeo (male participants) or Juliet (female participants) from Shakespeare's drama. Compared to responding as oneself, responding in character produced global reductions in brain activity and, particularly, deactivations in the cortical midline network of the frontal lobe, including the dorsomedial and ventromedial prefrontal cortices. Thus, portraying a character through acting seems to be a deactivation-driven process, perhaps representing a ‘loss of self'.

scholarly journals Neural tracking of subjective value under riskand ambiguity in adolescence

2019 ◽  
Vol 19 (6) ◽  
pp. 1364-1378 ◽  
Author(s):  
Neeltje E. Blankenstein ◽  
Anna C. K. van Duijvenvoorde
Keyword(s):  
Brain Activation ◽  
Superior Temporal Gyrus ◽  
Building Blocks ◽  
Brain Regions ◽  
Activation Patterns ◽  
Subjective Value ◽  
Adolescent Risk ◽  
Dorsolateral Prefrontal ◽  
Adolescent Sample ◽  
Superior Parietal Cortex

Abstract Although many neuroimaging studies on adolescent risk taking have focused on brain activation during outcome valuation, less attention has been paid to the neural correlates of choice valuation. Subjective choice valuation may be particularly influenced by whether a choice presents risk (known probabilities) or ambiguity (unknown probabilities), which has rarely been studied in developmental samples. Therefore, we examined the neural tracking of subjective value during choice under risk and ambiguity in a large sample of adolescents (N = 188, 12–22 years). Specifically, we investigated which brain regions tracked subjective value coding under risk and ambiguity. A model-based approach to estimate individuals’ risk and ambiguity attitudes showed prominent variation in individuals’ aversions to risk and ambiguity. Furthermore, participants subjectively experienced the ambiguous options as being riskier than the risky options. Subjective value tracking under risk was coded by activation in ventral striatum and superior parietal cortex. Subjective value tracking under ambiguity was coded by dorsolateral prefrontal cortex (PFC) and superior temporal gyrus activation. Finally, overlapping activation in the dorsomedial PFC was observed for subjective value under both conditions. Overall, this is the first study to chart brain activation patterns for subjective choice valuation under risk and ambiguity in an adolescent sample, which shows that the building blocks for risk and ambiguity processing are already present in early adolescence. Finally, we highlight the potential of combining behavioral modeling with fMRI for investigating choice valuation in adolescence, which may ultimately aid in understanding who takes risks and why.

The Neural Basis of Escape Behavior in Vertebrates

2020 ◽  
Vol 43 (1) ◽  
pp. 417-439 ◽  
Author(s):  
Tiago Branco ◽  
Peter Redgrave
Keyword(s):  
Neural Circuits ◽  
Escape Behavior ◽  
Building Blocks ◽  
Normative Theory ◽  
Neural Systems ◽  
Adaptive Behaviors ◽  
Neural Basis ◽  
Sensory Stimuli ◽  
Evolutionarily Conserved ◽  
Escape Behaviors

Escape is one of the most studied animal behaviors, and there is a rich normative theory that links threat properties to evasive actions and their timing. The behavioral principles of escape are evolutionarily conserved and rely on elementary computational steps such as classifying sensory stimuli and executing appropriate movements. These are common building blocks of general adaptive behaviors. Here we consider the computational challenges required for escape behaviors to be implemented, discuss possible algorithmic solutions, and review some of the underlying neural circuits and mechanisms. We outline shared neural principles that can be implemented by evolutionarily ancient neural systems to generate escape behavior, to which cortical encephalization has been added to allow for increased sophistication and flexibility in responding to threat.

Perceptual Representations and the Vividness of Stimulus-Triggered and Stimulus-Independent Experiences

2020 ◽  
Vol 15 (5) ◽  
pp. 1200-1213 ◽  
Author(s):  
Peter Fazekas ◽  
Georgina Nemeth ◽  
Morten Overgaard
Keyword(s):  
Working Memory ◽  
Mental Imagery ◽  
Information Exchange ◽  
Activity Patterns ◽  
Mind Wandering ◽  
Brain Regions ◽  
Neural Basis ◽  
Fine Grained ◽  
Common Framework ◽  
Cortical Regions

In recent years, researchers from independent subfields have begun to engage with the idea that the same cortical regions that contribute to on-line perception are recruited during and underlie off-line activities such as information maintenance in working memory, mental imagery, hallucinations, dreaming, and mind wandering. Accumulating evidence suggests that in all of these cases the activity of posterior brain regions provides the contents of experiences. This article is intended to move one step further by exploring specific links between the vividness of experiences, which is a characteristic feature of consciousness regardless of its actual content, and certain properties of the content-specific neural-activity patterns. Investigating the mechanisms that underlie mental imagery and its relation to working memory and the processes responsible for mind wandering and its similarities to dreaming form two clusters of research that are in the forefront of the recent scientific study of mental phenomena, yet communication between these two clusters has been surprisingly sparse. Here our aim is to foster such information exchange by articulating a hypothesis about the fine-grained phenomenological structure determining subjective vividness and its possible neural basis that allows us to shed new light on these mental phenomena by bringing them under a common framework.

scholarly journals Brain structural correlates of functional capacity in first-episode psychosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Erkan Alkan ◽  
Geoff Davies ◽  
Kathy Greenwood ◽  
Simon L. Evans
Keyword(s):  
Functional Capacity ◽  
Gray Matter Volume ◽  
Brain Regions ◽  
First Episode Psychosis ◽  
First Episode ◽  
Control Group ◽  
Neural Basis ◽  
Antipsychotic Therapy ◽  
Brain Volumes ◽  
Episode Psychosis

Abstract Impaired functional capacity is a core feature of schizophrenia and presents even in first-episode psychosis (FEP) patients. Impairments in daily functioning tend to persist despite antipsychotic therapy but their neural basis is less clear. Previous studies suggest that volume loss in frontal cortex might be an important contributor, but findings are inconsistent. We aimed to comprehensively investigate the brain structural correlates of functional capacity in FEP using MRI and a reliable objective measure of functioning [University of California, San Diego Performance-Based Skills Assessment (UPSA)]. In a sample of FEP (n = 39) and a well-matched control group (n = 21), we measured cortical thickness, gray matter volume, and white matter tract integrity (fractional anisotropy, FA) within brain regions implicated by previous work. The FEP group had thinner cortex in various frontal regions and fusiform, and reduced FA in inferior longitudinal fasciculus (ILF). In FEP, poorer functional capacity correlated with reduced superior frontal volume and lower FA in left ILF. Importantly, frontal brain volumes and integrity of the ILF were identified as the structural correlates of functional capacity in FEP, controlling for other relevant factors. These findings enhance mechanistic understanding of functional capacity deficits in schizophrenia by specifying the underlying neural correlates. In future, this could help inform intervention strategies.

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