scholarly journals Representation of Grammatical Categories of Words in the Brain

1995 ◽  
Vol 7 (3) ◽  
pp. 396-407 ◽  
Author(s):  
Argye E. Hillis ◽  
Alfonso Caramazza
Keyword(s):  
Neural Mechanisms ◽  
Single Patient ◽  
Grammatical Category ◽  
Lexical Knowledge ◽  
Double Dissociation ◽  
Category Information ◽  
Orthographic Representations ◽  
Organizational Principle ◽  
The Brain ◽  
Verbal Output

We report the performance of a patient who, as a consequence of left frontal and temporoparietal strokes, makes far more errors on nouns than on verbs in spoken output tasks, but makes far more errors on verbs than on nouns in written input tasks. This double dissociation within a single patient with respect to grammatical category provides evidence for the hypothesis that phonological and orthographic representations of nouns and verbs are processed by independent neural mechanisms. Furthermore, the opposite dissociation in the verbal output modality, an advantage for nouns over verbs in spoken tasks, by a different patient using the same stimuli has also been reported (Caramazza & Hillis, 1991). This double dissociation across patients on the same task indicates that results cannot be ascribed to "greater difficulty" with one type of stimulus, and provides further evidence for the view that grammatical category information is an important organizational principle of lexical knowledge in the brain.

scholarly journals Antagonism between brain regions relevant for cognitive control and emotional memory facilitates the generation of humorous ideas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Florian Bitsch ◽  
Philipp Berger ◽  
Andreas Fink ◽  
Arne Nagels ◽  
Benjamin Straube ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Positive Emotions ◽  
Emotional Memory ◽  
Brain Regions ◽  
Neural Mechanisms ◽  
Functional Magnetic Resonance ◽  
Frontal Brain ◽  
Successful Resolution ◽  
Neural Underpinnings ◽  
The Brain

AbstractThe ability to generate humor gives rise to positive emotions and thus facilitate the successful resolution of adversity. Although there is consensus that inhibitory processes might be related to broaden the way of thinking, the neural underpinnings of these mechanisms are largely unknown. Here, we use functional Magnetic Resonance Imaging, a humorous alternative uses task and a stroop task, to investigate the brain mechanisms underlying the emergence of humorous ideas in 24 subjects. Neuroimaging results indicate that greater cognitive control abilities are associated with increased activation in the amygdala, the hippocampus and the superior and medial frontal gyrus during the generation of humorous ideas. Examining the neural mechanisms more closely shows that the hypoactivation of frontal brain regions is associated with an hyperactivation in the amygdala and vice versa. This antagonistic connectivity is concurrently linked with an increased number of humorous ideas and enhanced amygdala responses during the task. Our data therefore suggests that a neural antagonism previously related to the emergence and regulation of negative affective responses, is linked with the generation of emotionally positive ideas and may represent an important neural pathway supporting mental health.

Neural Mechanisms of Negative Symptoms

1989 ◽  
Vol 155 (S7) ◽  
pp. 93-98 ◽  
Author(s):  
Nancy C. Andreasen
Keyword(s):  
Frontal Cortex ◽  
Negative Symptoms ◽  
Neural Mechanism ◽  
Brain Regions ◽  
Brain Dysfunction ◽  
Neural Mechanisms ◽  
Dementia Praecox ◽  
Intellectual Abilities ◽  
The Brain ◽  
Psychic Mechanisms

When Kraepelin originally defined and described dementia praecox, he assumed that it was due to some type of neural mechanism. He hypothesised that abnormalities could occur in a variety of brain regions, including the prefrontal, auditory, and language regions of the cortex. Many members of his department, including Alzheimer and Nissl, were actively involved in the search for the neuropathological lesions that would characterise schizophrenia. Although Kraepelin did not use the term ‘negative symptoms', he describes them comprehensively and states explicitly that he believes the symptoms of schizophrenia can be explained in terms of brain dysfunction:“If it should be confirmed that the disease attacks by preference the frontal areas of the brain, the central convolutions and central lobes, this distribution would in a certain measure agree with our present views about the site of the psychic mechanisms which are principally injured by the disease. On various grounds, it is easy to believe that the frontal cortex, which is specially well developed in man, stands in closer relation to his higher intellectual abilities, and these are the faculties which in our patients invariably suffer profound loss in contrast to memory and acquired ability.” Kraepelin (1919, p. 219)

scholarly journals Category representations in the brain are both discretely localized and widely distributed

2018 ◽  
Vol 119 (6) ◽  
pp. 2256-2264 ◽  
Author(s):  
Zarrar Shehzad ◽  
Gregory McCarthy
Keyword(s):  
Functional Mri ◽  
Brain Connectivity ◽  
Strong Support ◽  
Brain Regions ◽  
Distributed Representations ◽  
Domain Specific ◽  
Category Information ◽  
Shared Information ◽  
Unique Domain ◽  
The Brain

Whether category information is discretely localized or represented widely in the brain remains a contentious issue. Initial functional MRI studies supported the localizationist perspective that category information is represented in discrete brain regions. More recent fMRI studies using machine learning pattern classification techniques provide evidence for widespread distributed representations. However, these latter studies have not typically accounted for shared information. Here, we find strong support for distributed representations when brain regions are considered separately. However, localized representations are revealed by using analytical methods that separate unique from shared information among brain regions. The distributed nature of shared information and the localized nature of unique information suggest that brain connectivity may encourage spreading of information but category-specific computations are carried out in distinct domain-specific regions. NEW & NOTEWORTHY Whether visual category information is localized in unique domain-specific brain regions or distributed in many domain-general brain regions is hotly contested. We resolve this debate by using multivariate analyses to parse functional MRI signals from different brain regions into unique and shared variance. Our findings support elements of both models and show information is initially localized and then shared among other regions leading to distributed representations being observed.

scholarly journals Talent in the taxi: a model system for exploring expertise

2009 ◽  
Vol 364 (1522) ◽  
pp. 1407-1416 ◽  
Author(s):  
Katherine Woollett ◽  
Hugo J. Spiers ◽  
Eleanor A. Maguire
Keyword(s):  
Model System ◽  
Neural Mechanisms ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Taxi Drivers ◽  
The Brain ◽  
Use Of Expertise ◽  
Widespread Interest ◽  
Key Questions ◽  
Extensive Practice

While there is widespread interest in and admiration of individuals with exceptional talents, surprisingly little is known about the cognitive and neural mechanisms underpinning talent, and indeed how talent relates to expertise. Because many talents are first identified and nurtured in childhood, it can be difficult to determine whether talent is innate, can be acquired through extensive practice or can only be acquired in the presence of the developing brain. We sought to address some of these issues by studying healthy adults who acquired expertise in adulthood. We focused on the domain of memory and used licensed London taxi drivers as a model system. Taxi drivers have to learn the layout of 25 000 streets in London and the locations of thousands of places of interest, and pass stringent examinations in order to obtain an operating licence. Using neuropsychological assessment and structural and functional magnetic resonance imaging, we addressed a range of key questions: in the context of a fully developed brain and an average IQ, can people acquire expertise to an exceptional level; what are the neural signatures, both structural and functional, associated with the use of expertise; does expertise change the brain compared with unskilled control participants; does it confer any cognitive advantages, and similarly, does it come at a cost to other functions? By studying retired taxi drivers, we also consider what happens to their brains and behaviour when experts stop using their skill. Finally, we discuss how the expertise of taxi drivers might relate to the issue of talent and innate abilities. We suggest that exploring talent and expertise in this manner could have implications for education, rehabilitation of patients with cognitive impairments, understanding individual differences and possibly conditions such as autism where exceptional abilities can be a feature.

Domain-Specific Knowledge Systems in the Brain: The Animate-Inanimate Distinction

1998 ◽  
Vol 10 (1) ◽  
pp. 1-34 ◽  
Author(s):  
Alfonso Caramazza ◽  
Jennifer R. Shelton
Keyword(s):  
Knowledge Systems ◽  
Neural Mechanisms ◽  
Specific Knowledge ◽  
Knowledge Framework ◽  
Semantic Categories ◽  
Domain Specific ◽  
Domain Specific Knowledge ◽  
Cognitive Neuropsychological ◽  
The Brain ◽  
Selective Impairment

We claim that the animate and inanimate conceptual categories represent evolutionarily adapted domain-specific knowledge systems that are subserved by distinct neural mechanisms, thereby allowing for their selective impairment in conditions of brain damage. On this view, (some of) the category-specific deficits that have recently been reported in the cognitive neuropsychological literature—for example, the selective damage or sparing of knowledge about animals—are truly categorical effects. Here, we articulate and defend this thesis against the dominant, reductionist theory of category-specific deficits, which holds that the categorical nature of the deficits is the result of selective damage to noncategorically organized visual or functional semantic subsystems. On the latter view, the sensory/functional dimension provides the fundamental organizing principle of the semantic system. Since, according to the latter theory, sensory and functional properties are differentially important in determining the meaning of the members of different semantic categories, selective damage to the visual or the functional semantic subsystem will result in a category-like deficit. A review of the literature and the results of a new case of category-specific deficit will show that the domain-specific knowledge framework provides a better account of category-specific deficits than the sensory/functional dichotomy theory.

scholarly journals Brain Syndemics: Cognitive Deficit, Pathways of Interaction, and the Biology of Inequality

2021 ◽  
pp. 1-12
Author(s):  
Merrill Singer ◽  
Merrill Singer
Keyword(s):  
Air Pollution ◽  
Social Inequality ◽  
Chronic Stress ◽  
Cognitive Deficit ◽  
Developmental Delays ◽  
Neural Mechanisms ◽  
Social Discrimination ◽  
Behavioural And Emotional Problems ◽  
The Brain ◽  
Disadvantaged Families

Children born into and raised in disadvantaged families tend to experience poorer health and more developmental delays, lower achievement, and a greater number of behavioural and emotional problems than children from wealthier homes. There is growing evidence that poverty and social inequality leave their imprint on brain structure as well. The brain exhibits considerable plasticity, one expression of which is shaped by the biology of inequality. A specific consequence is cognitive deficit found among children raised in poverty and subject to social discrimination. This paper argues that several pathways impacted by poverty, including chronic stress, malnutrition, exposure to heightened levels of air pollution, and other toxin exposures, syndemically link social inequality to underlying neural mechanisms and to suboptimal brain development and structure. These deficits need not be permanent and are reversible through urgently needed structural, socio-economic intervention.

scholarly journals Neural Mechanisms of Inflammation-Induced Fever

2018 ◽  
Vol 24 (4) ◽  
pp. 381-399 ◽  
Author(s):  
Anders Blomqvist ◽  
David Engblom
Keyword(s):  
Peripheral Nerves ◽  
Circumventricular Organs ◽  
Neural Mechanisms ◽  
Prostaglandin E ◽  
Receptor Subtype ◽  
Common Symptom ◽  
Immune Challenge ◽  
Brain Endothelial Cells ◽  
Efferent Limb ◽  
The Brain

Fever is a common symptom of infectious and inflammatory disease. It is well-established that prostaglandin E2 is the final mediator of fever, which by binding to its EP3 receptor subtype in the preoptic hypothalamus initiates thermogenesis. Here, we review the different hypotheses on how the presence of peripherally released pyrogenic substances can be signaled to the brain to elicit fever. We conclude that there is unequivocal evidence for a humoral signaling pathway by which proinflammatory cytokines, through their binding to receptors on brain endothelial cells, evoke fever by eliciting prostaglandin E2 synthesis in these cells. The evidence for a role for other signaling routes for fever, such as signaling via circumventricular organs and peripheral nerves, as well as transfer into the brain of peripherally synthesized prostaglandin E2 are yet far from conclusive. We also review the efferent limb of the pyrogenic pathways. We conclude that it is well established that prostaglandin E2 binding in the preoptic hypothalamus produces fever by disinhibition of presympathetic neurons in the brain stem, but there is yet little understanding of the mechanisms by which factors such as nutritional status and ambient temperature shape the response to the peripheral immune challenge.

rethinking brain asymmetries in humans

2005 ◽  
Vol 28 (4) ◽  
pp. 598-599
Author(s):  
bianca dräger ◽  
caterina breitenstein ◽  
stefan knecht
Keyword(s):  
Bimodal Distribution ◽  
Language Lateralization ◽  
Evolutionarily Conserved ◽  
Organizational Principle ◽  
Directional Asymmetries ◽  
The Right ◽  
The Brain ◽  
Biological Advantage

similar to directional asymmetries in animals, language lateralization in humans follows a bimodal distribution. a majority of individuals are lateralized to the left and a minority of individuals are lateralized to the right side of the brain. however, a biological advantage for either lateralization is lacking. the scenario outlined by vallortigara & rogers (v&r) suggests that language lateralization in humans is not specific to language or human speciation but simply follows an evolutionarily conserved organizational principle of the brain.

scholarly journals Multiple timescales of neural dynamics and integration of task-relevant signals across cortex

2020 ◽  
Vol 117 (36) ◽  
pp. 22522-22531 ◽  
Author(s):  
Mehran Spitmaan ◽  
Hyojung Seo ◽  
Daeyeol Lee ◽  
Alireza Soltani
Keyword(s):  
Cortical Area ◽  
Dynamic Decision Making ◽  
Neural Dynamics ◽  
Neural Processing ◽  
Neuronal Dynamics ◽  
Time Constants ◽  
Multiple Timescales ◽  
Comprehensive Method ◽  
Organizational Principle ◽  
The Brain

A long-lasting challenge in neuroscience has been to find a set of principles that could be used to organize the brain into distinct areas with specific functions. Recent studies have proposed the orderly progression in the time constants of neural dynamics as an organizational principle of cortical computations. However, relationships between these timescales and their dependence on response properties of individual neurons are unknown, making it impossible to determine how mechanisms underlying such a computational principle are related to other aspects of neural processing. Here, we developed a comprehensive method to simultaneously estimate multiple timescales in neuronal dynamics and integration of task-relevant signals along with selectivity to those signals. By applying our method to neural and behavioral data during a dynamic decision-making task, we found that most neurons exhibited multiple timescales in their response, which consistently increased from parietal to prefrontal and cingulate cortex. While predicting rates of behavioral adjustments, these timescales were not correlated across individual neurons in any cortical area, resulting in independent parallel hierarchies of timescales. Additionally, none of these timescales depended on selectivity to task-relevant signals. Our results not only suggest the existence of multiple canonical mechanisms for increasing timescales of neural dynamics across cortex but also point to additional mechanisms that allow decorrelation of these timescales to enable more flexibility.

Sign in / Sign up

Export Citation Format

Share Document