scholarly journals Limb Preference in Animals: New Insights into the Evolution of Manual Laterality in Hominids

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 96
Author(s):  
Grégoire Boulinguez-Ambroise ◽  
Juliette Aychet ◽  
Emmanuelle Pouydebat
Keyword(s):  
Functional Neuroimaging ◽  
Hemispheric Specialization ◽  
Brain Regions ◽  
Brain Lateralization ◽  
Intentional Communication ◽  
Wide Range ◽  
Specific Trait ◽  
Communicative Gestures ◽  
The Brain ◽  
Human Specific

Until the 1990s, the notion of brain lateralization—the division of labor between the two hemispheres—and its more visible behavioral manifestation, handedness, remained fiercely defined as a human specific trait. Since then, many studies have evidenced lateralized functions in a wide range of species, including both vertebrates and invertebrates. In this review, we highlight the great contribution of comparative research to the understanding of human handedness’ evolutionary and developmental pathways, by distinguishing animal forelimb asymmetries for functionally different actions—i.e., potentially depending on different hemispheric specializations. Firstly, lateralization for the manipulation of inanimate objects has been associated with genetic and ontogenetic factors, with specific brain regions’ activity, and with morphological limb specializations. These could have emerged under selective pressures notably related to the animal locomotion and social styles. Secondly, lateralization for actions directed to living targets (to self or conspecifics) seems to be in relationship with the brain lateralization for emotion processing. Thirdly, findings on primates’ hand preferences for communicative gestures accounts for a link between gestural laterality and a left-hemispheric specialization for intentional communication and language. Throughout this review, we highlight the value of functional neuroimaging and developmental approaches to shed light on the mechanisms underlying human handedness.

scholarly journals A review of the new minimally invasive brain stimulation techniques in psychiatry

2001 ◽  
Vol 23 (2) ◽  
pp. 100-109 ◽  
Author(s):  
Jeong-Ho Chae ◽  
Xingbao Li ◽  
Ziad Nahas ◽  
F. Andrew Kozel ◽  
Mark S. George
Keyword(s):  
Minimally Invasive ◽  
Brain Stimulation ◽  
Functional Neuroimaging ◽  
Neuropsychiatric Disorders ◽  
Brain Regions ◽  
Therapeutic Tools ◽  
Invasive Techniques ◽  
The Brain ◽  
Neuroimaging Techniques ◽  
Deep Brain

New knowledge about the specific brain regions involved in neuropsychiatric disorders is rapidly evolving due to recent advances in functional neuroimaging techniques. The ability to stimulate the brain in awake alert adults without neurosurgery is a real advance that neuroscientists have long dreamed for. Several novel and minimally invasive techniques to stimulate the brain have recently developed. Among these newer somatic interventions, transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS) and deep brain stimulation (DBS) show promise as therapeutic tools in the treatment of neuropsychiatric disorders. This article reviews the history, methodology, and the future of these minimally invasive brain stimulation (MIBS) techniques and their emerging research and therapeutic applications in psychiatry

scholarly journals Predication Drives Verb Cortical Signatures

2014 ◽  
Vol 26 (8) ◽  
pp. 1829-1839 ◽  
Author(s):  
Mireia Hernández ◽  
Scott L. Fairhall ◽  
Alessandro Lenci ◽  
Marco Baroni ◽  
Alfonso Caramazza
Keyword(s):  
Functional Neuroimaging ◽  
Specific Property ◽  
Brain Regions ◽  
Grammatical Class ◽  
Middle Temporal ◽  
Lexical Feature ◽  
Left Posterior ◽  
Word Classes ◽  
The Brain ◽  
Fundamental Units

Verbs and nouns are fundamental units of language, but their neural instantiation remains poorly understood. Neuropsychological research has shown that nouns and verbs can be damaged independently of each other, and neuroimaging research has found that several brain regions respond differentially to the two word classes. However, the semantic–lexical properties of verbs and nouns that drive these effects remain unknown. Here we show that the most likely candidate is predication: a core lexical feature involved in binding constituent arguments (boy, candies) into a unified syntactic–semantic structure expressing a proposition (the boy likes the candies). We used functional neuroimaging to test whether the intrinsic “predication-building” function of verbs is what drives the verb–noun distinction in the brain. We first identified verb-preferring regions with a localizer experiment including verbs and nouns. Then, we examined whether these regions are sensitive to transitivity—an index measuring its tendency to select for a direct object. Transitivity is a verb-specific property lying at the core of its predication function. Neural activity in the left posterior middle temporal and inferior frontal gyri correlates with transitivity, indicating sensitivity to predication. This represents the first evidence that grammatical class preference in the brain is driven by a word's function to build predication structures.

scholarly journals Sociality and Interaction Envelope Organize Visual Action Representations

2019 ◽  
Author(s):  
Leyla Tarhan ◽  
Talia Konkle
Keyword(s):  
Visual Cortex ◽  
Large Scale ◽  
Functional Neuroimaging ◽  
Action Observation ◽  
The Body ◽  
Whole Body ◽  
Action Perception ◽  
Social Content ◽  
Wide Range ◽  
The Brain

Humans observe a wide range of actions in their surroundings. How is the visual cortex organized to process this diverse input? Using functional neuroimaging, we measured brain responses while participants viewed short videos of everyday actions, then probed the structure in these responses using voxel-wise encoding modeling. Responses were well fit by feature spaces that capture the body parts involved in an action and the action’s targets (i.e. whether the action was directed at an object, another person, the actor, and space). Clustering analyses revealed five large-scale networks that summarized the voxel tuning: one related to social aspects of an action, and four related to the scale of the interaction envelope, ranging from fine-scale manipulations directed at objects, to large-scale whole-body movements directed at distant locations. We propose that these networks reveal the major representational joints in how actions are processed by visual regions of the brain.Significance StatementHow does the brain perceive other people’s actions? Prior work has established that much of the visual cortex is active when observing others’ actions. However, this activity reflects a wide range of processes, from identifying a movement’s direction to recognizing its social content. We investigated how these diverse processes are organized within the visual cortex. We found that five networks respond during action observation: one that is involved in processing actions’ social content, and four that are involved in processing agent-object interactions and the scale of the effect that these actions have on the world (its “interaction envelope”). Based on these findings, we propose that sociality and interaction envelope size are two of the major features that organize action perception in the visual cortex.

scholarly journals Studies of Altered Social Cognition in Neuropsychiatric Disorders Using Functional Neuroimaging

2002 ◽  
Vol 47 (4) ◽  
pp. 327-336 ◽  
Author(s):  
Cheryl L Grady ◽  
Michelle L Keightley
Keyword(s):  
Social Cognition ◽  
Brain Function ◽  
Functional Neuroimaging ◽  
Neuropsychiatric Disorders ◽  
Brain Regions ◽  
The Past ◽  
Complex Interactions ◽  
Social Abilities ◽  
The Brain ◽  
Self Reference

In this paper, we review studies using functional neuroimaging to examine cognition in neuropsychiatric disorders. The focus is on social cognition, which is a topic that has received increasing attention over the past few years. A network of brain regions is proposed for social cognition that includes regions involved in processes relevant to social functioning (for example, self reference and emotion). We discuss the alterations of activity in these areas in patients with autism, depression, schizophrenia, and posttraumatic stress disorder in relation to deficits in social behaviour and symptoms. The evidence to date suggests that there may be some specificity of the brain regions involved in these 4 disorders, but all are associated with dysfunction in the amygdala and dorsal cingulate gyrus. Although there is much work remaining in this area, we are beginning to understand the complex interactions of brain function and behaviour that lead to disruptions of social abilities.

scholarly journals Functionnectome: a framework to analyse the contribution of brain circuits to fMRI

2021 ◽  
Author(s):  
Victor Nozais ◽  
Stephanie Forkel ◽  
Chris Foulon ◽  
Laurent Petit ◽  
Michel Thiebaut de Schotten
Keyword(s):  
White Matter ◽  
Functional Neuroimaging ◽  
Brain Regions ◽  
Functional Networks ◽  
Language Functions ◽  
Brain Circuits ◽  
Novel Method ◽  
Joint Contribution ◽  
The Relationship ◽  
The Brain

Abstract In recent years, the field of functional neuroimaging has moved from a pure localisationist approach of isolated functional brain regions to a more integrated view of those regions within functional networks. The methods used to investigate such networks, however, rely on local signals in grey matter and are limited in identifying anatomical circuitries supporting the interaction between brain regions. Mapping the brain circuits mediating the functional signal between brain regions would propel forward our understanding of the brain’s functional signatures and dysfunctions. We developed a novel method to unravel the relationship between brain circuits and functions: The Functionnectome. The Functionectome combines the functional signal from fMRI with the anatomy of white matter brain circuits to unlock and chart the first maps of functional white matter. To showcase the versatility of this new method, we provide the first functional white matter maps revealing the joint contribution of connected areas to motor, working memory, and language functions. The Functionnectome comes with an open source companion software and opens new avenues into studying functional networks by applying the method to already existing dataset and beyond task fMRI.

scholarly journals A neuromechanistic model for rhythmic beat generation

2018 ◽  
Author(s):  
Amitabha Bose ◽  
Áine Byrne ◽  
John Rinzel
Keyword(s):  
Experimental Studies ◽  
Brain Regions ◽  
Beat Generation ◽  
Systems Model ◽  
Hard Time ◽  
Wide Range ◽  
Neuronal Network Model ◽  
Musical Traditions ◽  
Algorithmic Approaches ◽  
The Brain

AbstractWhen listening to music, humans can easily identify and move to the beat. Numerous experimental studies have identified brain regions that may be involved with beat perception and representation. Several theoretical and algorithmic approaches have been proposed to account for this ability. Related to, but different from the issue of how we perceive a beat, is the question of how we learn to generate and hold a beat. In this paper, we introduce a neuronal framework for a beat generator that is capable of learning isochronous rhythms over a range of frequencies that are relevant to music and speech. Our approach combines ideas from error-correction and entrainment models to investigate the dynamics of how a biophysically-based neuronal network model synchronizes its period and phase to match that of an external stimulus. The model makes novel use of on-going faster gamma rhythms to form a set of discrete clocks that provide estimates, but not exact information, of how well the beat generator spike times match those of a stimulus sequence. The beat generator is endowed with plasticity allowing it to quickly learn and thereby adjust its spike times to achieve synchronization. Our model makes generalizable predictions about the existence of asymmetries in the synchronization process, as well as specific predictions about resynchronization times after changes in stimulus tempo or phase. Analysis of the model demonstrates that accurate rhythmic time keeping can be achieved over a range of frequencies relevant to music, in a manner that is robust to changes in parameters and to the presence of noise.Author summaryMusic is integral to human experience and is appreciated across a wide range of cultures. Although many features distinguish different musical traditions, rhythm is central to nearly all. Most humans can detect and move along to the beat through finger or foot tapping, hand clapping or other bodily movements. But many people have a hard time “keeping a beat”, or say they have “no sense of rhythm”. There appears to be a disconnect between our ability to perceive a beat versus our ability to produce a beat, as a drummer would do as part of a musical group. Producing a beat requires beat generation, the process by which we learn how to keep track of the specific time intervals between beats, as well as executing the motor movement needed to produce the sound associated with a beat. In this paper, we begin to explore neural mechanisms that may be responsible for our ability to generate and keep a beat. We develop a computational model that includes different neurons and shows how they cooperate to learn a beat and keep it, even after the stimulus is removed, across a range of frequencies relevant to music. Our dynamical systems model leads to predictions for how the brain may react when learning a beat. Our findings and techniques should be widely applicable to those interested in understanding how the brain processes time, particularly in the context of music.

scholarly journals The Neural Basis of Motivational Influences on Cognitive Control

2017 ◽  
Author(s):  
Cameron Parro ◽  
Matthew L Dixon ◽  
Kalina Christoff
Keyword(s):  
Cognitive Control ◽  
Large Scale ◽  
Functional Neuroimaging ◽  
Meta Analysis ◽  
Premotor Cortex ◽  
Likelihood Estimation ◽  
Brain Regions ◽  
Control Mechanisms ◽  
Neural Basis ◽  
The Brain

AbstractCognitive control mechanisms support the deliberate regulation of thought and behavior based on current goals. Recent work suggests that motivational incentives improve cognitive control, and has begun to elucidate the brain regions that may support this effect. Here, we conducted a quantitative meta-analysis of neuroimaging studies of motivated cognitive control using activation likelihood estimation (ALE) and Neurosynth in order to delineate the brain regions that are consistently activated across studies. The analysis included functional neuroimaging studies that investigated changes in brain activation during cognitive control tasks when reward incentives were present versus absent. The ALE analysis revealed consistent recruitment in regions associated with the frontoparietal control network including the inferior frontal sulcus (IFS) and intraparietal sulcus (IPS), as well as consistent recruitment in regions associated with the salience network including the anterior insula and anterior mid-cingulate cortex (aMCC). A large-scale exploratory meta-analysis using Neurosynth replicated the ALE results, and also identified the caudate nucleus, nucleus accumbens, medial thalamus, inferior frontal junction/premotor cortex (IFJ/PMC), and hippocampus. Finally, we conducted separate ALE analyses to compare recruitment during cue and target periods, which tap into proactive engagement of rule-outcome associations, and the mobilization of appropriate viscero-motor states to execute a response, respectively. We found that largely distinct sets of brain regions are recruited during cue and target periods. Altogether, these findings suggest that flexible interactions between frontoparietal, salience, and dopaminergic midbrain-striatal networks may allow control demands to be precisely tailored based on expected value.

scholarly journals Transmission time delays organize the brain network synchronization

2019 ◽  
Vol 377 (2153) ◽  
pp. 20180132 ◽  
Author(s):  
Spase Petkoski ◽  
Viktor K. Jirsa
Keyword(s):  
Time Delays ◽  
Phase Synchronization ◽  
Brain Regions ◽  
Brain Network ◽  
Temporal Organization ◽  
Delay Systems ◽  
Oscillatory Dynamics ◽  
Wide Range ◽  
Kuramoto Oscillators ◽  
The Brain

The timing of activity across brain regions can be described by its phases for oscillatory processes, and is of crucial importance for brain functioning. The structure of the brain constrains its dynamics through the delays due to propagation and the strengths of the white matter tracts. We use self-sustained delay-coupled, non-isochronous, nonlinearly damped and chaotic oscillators to study how spatio-temporal organization of the brain governs phase lags between the coherent activity of its regions. In silico results for the brain network model demonstrate a robust switching from in- to anti-phase synchronization by increasing the frequency, with a consistent lagging of the stronger connected regions. Relative phases are well predicted by an earlier analysis of Kuramoto oscillators, confirming the spatial heterogeneity of time delays as a crucial mechanism in shaping the functional brain architecture. Increased frequency and coupling are also shown to distort the oscillators by decreasing their amplitude, and stronger regions have lower, but more synchronized activity. These results indicate specific features in the phase relationships within the brain that need to hold for a wide range of local oscillatory dynamics, given that the time delays of the connectome are proportional to the lengths of the structural pathways. This article is part of the theme issue ‘Nonlinear dynamics of delay systems’.

Direct Comparison of Neural Systems Mediating Conscious and Unconscious Skill Learning

2002 ◽  
Vol 88 (3) ◽  
pp. 1451-1460 ◽  
Author(s):  
Daniel B. Willingham ◽  
Joanna Salidis ◽  
John D.E. Gabrieli
Keyword(s):  
Sequence Learning ◽  
Functional Neuroimaging ◽  
Brain Regions ◽  
Procedural Learning ◽  
Skill Learning ◽  
Adaptive Plasticity ◽  
Neural Systems ◽  
Motor Sequence ◽  
Learning Without Awareness ◽  
The Brain

Procedural learning, such as perceptual-motor sequence learning, has been suggested to be an obligatory consequence of practiced performance and to reflect adaptive plasticity in the neural systems mediating performance. Prior neuroimaging studies, however, have found that sequence learning accompanied with awareness (declarative learning) of the sequence activates entirely different brain regions than learning without awareness of the sequence (procedural learning). Functional neuroimaging was used to assess whether declarative sequence learning prevents procedural learning in the brain. Awareness of the sequence was controlled by changing the color of the stimuli to match or differ from the color used for random sequences. This allowed direct comparison of brain activation associated with procedural and declarative memory for an identical sequence. Activation occurred in a common neural network whether initial learning had occurred with or without awareness of the sequence, and whether subjects were aware or not aware of the sequence during performance. There was widespread additional activation associated with awareness of the sequence. This supports the view that some types of unconscious procedural learning occurs in the brain whether or not it is accompanied by conscious declarative knowledge.

New Methods of Brain Stimulation Are Improving Research and Therapy in Obsessive-Compulsive Disorder

CNS Spectrums ◽  
2000 ◽  
Vol 5 (S4) ◽  
pp. 12-17 ◽  
Author(s):  
Mark S. George
Keyword(s):  
Obsessive Compulsive Disorder ◽  
Brain Stimulation ◽  
Functional Neuroimaging ◽  
Brain Regions ◽  
Current Status ◽  
Obsessive Compulsive ◽  
New Techniques ◽  
Compulsive Disorder ◽  
The Past ◽  
The Brain

AbstractOver the past decade, new functional neuroimaging tools have enabled researchers to identify the specific brain regions involved in obsessive-compulsive disorder (OCD). More recently, researchers have perfected several new techniques for stimulating the brain. With some exceptions, these new brain stimulation techniques are regionally specific and less invasive than older methods. As a class, these “somatic interventions” build on prior neuroanatomic information about OCD. This article reviews the past and current status of these brain stimulation methodologies, which promise to revolutionize neuropsychiatric research and therapy over the next 10 to 20 years. As the brain circuits in OCD and the pharmacology within those circuits become better understood, these brain stimulation techniques hold particular promise in helping to understand and perhaps treat OCD.

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