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Physiological Reviews Oct 2011Language processing is a trait of human species. The knowledge about its neurobiological basis has been increased considerably over the past decades. Different brain... (Review)
Review
Language processing is a trait of human species. The knowledge about its neurobiological basis has been increased considerably over the past decades. Different brain regions in the left and right hemisphere have been identified to support particular language functions. Networks involving the temporal cortex and the inferior frontal cortex with a clear left lateralization were shown to support syntactic processes, whereas less lateralized temporo-frontal networks subserve semantic processes. These networks have been substantiated both by functional as well as by structural connectivity data. Electrophysiological measures indicate that within these networks syntactic processes of local structure building precede the assignment of grammatical and semantic relations in a sentence. Suprasegmental prosodic information overtly available in the acoustic language input is processed predominantly in a temporo-frontal network in the right hemisphere associated with a clear electrophysiological marker. Studies with patients suffering from lesions in the corpus callosum reveal that the posterior portion of this structure plays a crucial role in the interaction of syntactic and prosodic information during language processing.
Topics: Brain; Brain Mapping; Frontal Lobe; Humans; Language Development; Nerve Net; Speech Perception; Temporal Lobe
PubMed: 22013214
DOI: 10.1152/physrev.00006.2011 -
Epileptic Disorders : International... Dec 2004Frontal lobe epilepsy accounts for only 10-20% of the patients in surgical series, but the incidence in non-surgical patient cohorts seems to be much higher. The typical... (Review)
Review
Frontal lobe epilepsy accounts for only 10-20% of the patients in surgical series, but the incidence in non-surgical patient cohorts seems to be much higher. The typical clinical presentation of the seizures includes contralateral clonic movements, uni- or bilateral tonic motor activity as well as complex automatism. The yield of surface EEG may be limited due to the difficulty in detection of mesial or basal foci, and the patient may be misdiagnosed as having non-epileptic events. In addition, in patients with mesial frontal foci the epileptiform discharges may be mislateralized ("paradoxical lateralization"). Therefore, epilepsy surgery has been commonly considered as less promising in patients with frontal lobe epilepsy. However, the advent of sophisticated neuroimaging techniques, particularly MRI with epilepsy-specific sequences, has made it possible to delineate the epileptogenic lesion and detect a specific etiology, in an increasing number of patients. Thus, the success rate of epilepsy surgery in frontal lobe epilepsy is currently comparable to temporal lobe epilepsy, if the candidates are carefully selected. Patients with frontal lobe epilepsy who do not respond to anticonvulsive medication, and who are not eligible for epilepsy surgery may benefit from alternative approaches such as electrical brain stimulation.
Topics: Anticonvulsants; Brain Mapping; Diagnosis, Differential; Electroencephalography; Epilepsy, Frontal Lobe; Evoked Potentials; Frontal Lobe; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Prognosis; Psychosurgery; Treatment Outcome
PubMed: 15634619
DOI: No ID Found -
Journal of Clinical Neurophysiology :... Oct 2012Dorsolateral frontal lobe seizures often present as a diagnostic challenge. The diverse semiologies may not produce lateralizing or localizing signs and can appear... (Review)
Review
Dorsolateral frontal lobe seizures often present as a diagnostic challenge. The diverse semiologies may not produce lateralizing or localizing signs and can appear bizarre and suggest psychogenic events. Unfortunately, scalp electroencephalographic (EEG) and magnetic resonance imaging (MRI) are often unsatisfactory. It is not uncommon that these traditional diagnostic studies are either unhelpful or even misleading. In some cases, SPECT and positron emission tomography imaging can be an effective tool to identify the origin of seizures. However, these techniques and other emerging techniques all have limitations, and new approaches are needed to improve source localization.
Topics: Adult; Anticonvulsants; Brain Mapping; Brain Waves; Electroencephalography; Epilepsy, Frontal Lobe; Female; Frontal Lobe; Humans; Magnetic Resonance Imaging; Neurosurgical Procedures; Periodicity; Positron-Emission Tomography; Predictive Value of Tests; Tomography, Emission-Computed, Single-Photon; Treatment Outcome
PubMed: 23027094
DOI: 10.1097/WNP.0b013e31826b3c7c -
Trends in Psychiatry and Psychotherapy 2016To highlight the changes in the frontal lobe of the human brain in people with schizophrenia. (Review)
Review
OBJECTIVE:
To highlight the changes in the frontal lobe of the human brain in people with schizophrenia.
METHODS:
This was a qualitative review of the literature.
RESULTS:
Many schizophrenic patients exhibit functional, structural, and metabolic abnormalities in the frontal lobe. Some patients have few or no alterations, while some have more functional and structural changes than others. Magnetic resonance imaging (MRI) shows structural and functional changes in volume, gray matter, white matter, and functional activity in the frontal lobe, but the mechanisms underlying these changes are not yet fully understood.
CONCLUSION:
When schizophrenia is studied as an essential topic in the field of neuropsychiatry, neuroscientists find that the frontal lobe is the most commonly involved area of the human brain. A clear picture of how this lobe is affected in schizophrenia is still lacking. We therefore recommend that further research be conducted to improve understanding of the pathophysiology of this psychiatric dilemma.
Topics: Frontal Lobe; Humans; Schizophrenia
PubMed: 28076640
DOI: 10.1590/2237-6089-2015-0088 -
Epilepsia 1998On the basis of cytoarchitectural and functional studies, the frontal lobe can be subdivided into the primary motor cortex, premotor cortex, prefrontal cortex, and the... (Review)
Review
On the basis of cytoarchitectural and functional studies, the frontal lobe can be subdivided into the primary motor cortex, premotor cortex, prefrontal cortex, and the limbic and paralimbic cortices. However, we are still a long way from clearly identifying individual frontal lobe epilepsies. Instead, we are limited to a discussion of frontal lobe seizures arising from various regions of the frontal lobe. Supplementary motor area epilepsy and perirolandic epilepsy have been quite well defined, in contrast to syndromes involving other regions of the frontal lobe. Recent technological advances in neuroimaging, electroencephalography, magnetoencephalography and detailed videotape analysis of seizure semiology may enable us to delineate these frontal lobe syndromes with better accuracy, thereby improving outcome after epilepsy surgery.
Topics: Epilepsy, Frontal Lobe; Fluorodeoxyglucose F18; Frontal Lobe; Humans; Magnetic Resonance Imaging; Magnetoencephalography; Motor Cortex; Prefrontal Cortex; Terminology as Topic; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Treatment Outcome
PubMed: 9637594
DOI: 10.1111/j.1528-1157.1998.tb05126.x -
Epilepsia 1998The mesiofrontal cortex comprises a number of distinct anatomic and functional areas. Structural lesions and cortical dysgenesis are recognized causes of mesial frontal... (Review)
Review
The mesiofrontal cortex comprises a number of distinct anatomic and functional areas. Structural lesions and cortical dysgenesis are recognized causes of mesial frontal epilepsy, but a specific gene defect may also be important, as seen in some forms of familial frontal lobe epilepsy. The predominant seizure manifestations, which are not necessarily strictly correlated with a specific ictal onset zone, are absence, hypermotor, and postural tonic seizures. Other seizure types also occur. The task of localization of the epileptogenic zone can be challenging, whether EEG or imaging methods are used. Successful localization can lead to a rewarding outcome after epilepsy surgery, particularly in those with an imaged lesion.
Topics: Adolescent; Adult; Electrodes, Implanted; Electroencephalography; Epilepsy, Absence; Epilepsy, Frontal Lobe; Frontal Lobe; Gyrus Cinguli; Humans; Magnetic Resonance Imaging; Motor Cortex; Radionuclide Imaging; Treatment Outcome
PubMed: 9637593
DOI: 10.1111/j.1528-1157.1998.tb05125.x -
F1000Research 2020Even apparently simple choices, like selecting a dessert in a pastry shop, involve options characterized by multiple motivationally relevant attributes. Neuroeconomic... (Review)
Review
Even apparently simple choices, like selecting a dessert in a pastry shop, involve options characterized by multiple motivationally relevant attributes. Neuroeconomic research suggests that the human brain may track the subjective value of such options, allowing disparate reward-predictive information to be compared in a common currency. However, the brain mechanisms involved in identifying value-predictive features and combining these to assess the value of each decision option remain unclear. Here, we review recent evidence from studies of multi-attribute decision-making in people with focal frontal lobe damage and in healthy people undergoing functional magnetic resonance imaging. This work suggests that ventromedial and lateral prefrontal cortex and orbitofrontal cortex are important for forming value judgments under conditions of complexity. We discuss studies supporting the involvement of these regions in selecting among and evaluating option attributes during value judgment and decision-making and when learning from reward feedback. These findings are consistent with roles for these regions in guiding value construction. They argue for a more nuanced understanding of how ventral and lateral prefrontal cortex contribute to discovering and recognizing value, processes that are required under the complex conditions typical of many everyday decisions.
Topics: Decision Making; Frontal Lobe; Humans; Magnetic Resonance Imaging; Prefrontal Cortex; Reward
PubMed: 32161644
DOI: 10.12688/f1000research.21946.1 -
Brain and Language Jul 2013Thalamic nuclei associated with language including the ventral lateral, ventral anterior, intralaminar and mediodorsal form a hub that uniquely receives the output of... (Review)
Review
Thalamic nuclei associated with language including the ventral lateral, ventral anterior, intralaminar and mediodorsal form a hub that uniquely receives the output of the basal ganglia and cerebellum, and is connected with frontal (premotor and prefrontal) cortices through two parallel circuits: a thalamic pathway targets the middle frontal cortical layers focally, and the other innervates widely cortical layer 1, poised to recruit other cortices and thalamic nuclei for complex cognitive operations. Return frontal pathways to the thalamus originate from cortical layers 6 and 5. Information through this integrated thalamo-cortical system is gated by the inhibitory thalamic reticular nucleus and modulated by dopamine, representing a specialization in primates. The intricate dialogue of distinct thalamic nuclei with the basal ganglia, cerebellum, and specific dorsolateral prefrontal and premotor cortices associated with language, suggests synergistic roles in the complex but seemingly effortless sequential transformation of cognitive operations for speech production in humans.
Topics: Frontal Lobe; Humans; Language; Neural Pathways; Speech; Thalamic Nuclei
PubMed: 23211411
DOI: 10.1016/j.bandl.2012.10.001 -
Journal of Integrative Neuroscience Mar 2022Frontal lobe volume has been extensively researched in individuals with Autism spectrum disorder (ASD), though findings are yet to be summarised to explain the... (Review)
Review
Frontal lobe volume has been extensively researched in individuals with Autism spectrum disorder (ASD), though findings are yet to be summarised to explain the developmental trends of frontal lobe volume. The aim of the present study is to consolidate all existing frontal lobe volume and age data of autistic individuals below 30 years of age, and compare this data to non-autistic (N-ASD) controls. Following a systematic review, frontal lobe volume data were obtained from seven papers. Raw data, or the means and standard deviations of frontal lobe volume, and age, were obtained from the studies giving 372 autistic and 190 N-ASD participants. Data were plotted and analysed. Findings revealed that regression lines of fit for ASD ( = 0.33; = 0.52) and N-ASD ( = 0.14; = 0.39) were significantly different by diagnosis (linear = 0.002, quadratic = 0.02) with quadratic models providing significantly better fit within ASD ( 0.001) and N-ASD ( 0.001). Additional analyses revealed that frontal lobe volume was greater in autistic individuals than N-ASD between two and four years ( = 12.965, 0.005, η2 = 0.291). In the present study, there were distinct developmental trends for frontal lobe volume between ASD and N-ASD.
Topics: Autism Spectrum Disorder; Autistic Disorder; Frontal Lobe; Humans
PubMed: 35364645
DOI: 10.31083/j.jin2102057 -
Journal of Neurosurgical Sciences Dec 2021The frontal aslant tract (FAT) is an intralobar white matter fasciculus providing dense connections between the medial part of the superior frontal gyrus, in particular... (Review)
Review
The frontal aslant tract (FAT) is an intralobar white matter fasciculus providing dense connections between the medial part of the superior frontal gyrus, in particular the presupplementary motor area (SMA) and the SMA proper, and the lateral part of the frontal lobe, especially the inferior frontal gyrus. Although this tract has been characterized belatedly, it has received important attention in recent years due notably to its increasingly evidenced role in the speech and language networks. As cerebral tumors frequently affect the frontal lobe, an improved knowledge of the functional anatomy of the FAT is mandatory to refine the way neurosurgeries are performed and to give the patients the best opportunities to recover after surgery. In this work, we first describe the spatial arrangement of the FAT and detail its cortical projections. We then provide a comprehensive review of the functions supposedly mediated by this transverse frontal connectivity. It is structured following a tripartite organization where the linguistic (i.e. speech and language), supralinguistic (i.e. functions that interact with speech and language: executive functions, working memory, and social communication) and extralinguistic implications (i.e. functions outside the linguistic domain: visuospatial processing, praxis and motor skills) are successively addressed. We lastly discussed this knowledge in the context of wide-awake neurosurgeries for brain tumors. We emphasize the need to evaluate thoroughly the functions conveyed by FAT by means of longitudinally-designed studies to first estimate its plasticity potential and then to determine which tasks should be selected to avoid lasting impairments due to its disconnective breakdown.
Topics: Brain Mapping; Frontal Lobe; Humans; Language; Motor Cortex; Neural Pathways; Speech
PubMed: 33870673
DOI: 10.23736/S0390-5616.21.05344-3