Journal ArticleDOI
What catatonia can tell us about "top-down modulation": a neuropsychiatric hypothesis.
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It is hypothesized that similarities and differences between Parkinson's disease and catatonia may be accounted for by distinct kinds of modulation between Cortico-cortical and cortico-subcortic relations.Abstract:
Differential diagnosis of motor symptoms, for example, akinesia, may be difficult in clinical neuropsychiatry. Symptoms may be either of neurologic origin, for example, Parkinson's disease, or of psychiatric origin, for example, catatonia, leading to a so-called "conflict of paradigms." Despite their different origins, symptoms may appear more or less clinically similar. Possibility of dissociation between origin and clinical appearance may reflect functional brain organisation in general, and cortical-cortical/subcortical relations in particular. It is therefore hypothesized that similarities and differences between Parkinson's disease and catatonia may be accounted for by distinct kinds of modulation between cortico-cortical and cortico-subcortical relations. Catatonia can be characterized by concurrent motor, emotional, and behavioural symptoms. The different symptoms may be accounted for by dysfunction in orbitofrontal-prefrontal/parietal cortical connectivity reflecting "horizontal modulation" of cortico-cortical relation. Furthermore, alteration in "top-down modulation" reflecting "vertical modulation" of caudate and other basal ganglia by GABA-ergic mediated orbitofrontal cortical deficits may account for motor symptoms in catatonia. Parkinson's disease, in contrast, can be characterized by predominant motor symptoms. Motor symptoms may be accounted for by altered "bottom-up modulation" between dopaminergic mediated deficits in striatum and premotor/motor cortex. Clinical similarities between Parkinson's disease and catatonia with respect to akinesia may be related with involvement of the basal ganglia in both disorders. Clinical differences with respect to emotional and behavioural symptoms may be related with involvement of different cortical areas, that is, orbitofrontal/parietal and premotor/motor cortex implying distinct kinds of modulation--"vertical" and "horizontal" modulation, respectively.read more
Citations
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Journal ArticleDOI
Bridging emotion theory and neurobiology through dynamic systems modeling.
TL;DR: A psychological model of emotion–appraisal states with reference to neural processes is presented, identifying trigger, self-amplification, and self-stabilization phases of emotion-appRAisal states, leading to consolidating traits.
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Glutamate and the neural basis of the subjective effects of ketamine: a pharmaco-magnetic resonance imaging study.
J.F. William Deakin,Jane Lees,Shane McKie,Jaime Eduardo Cecílio Hallak,Steve R. Williams,Serdar M. Dursun +5 more
TL;DR: The results are compatible with the theory that the neural and subjective effects of ketamine involve increased glutamate release and may underpin 2 fundamental processes of psychosis: abnormal perceptual experiences and impaired cognitive-emotional evaluation of their significance.
Journal ArticleDOI
Catatonia: clinical aspects and neurobiological correlates.
TL;DR: This review synthesizes over 20 years of original research and comprehensive review articles with attention to the most recent findings to suggest that catatonia due to an underlying general medical condition and catatonian due to a psychiatric illness can be treated similarly and that the catatonic symptoms and the underlying illness must be addressed in both types.
Journal ArticleDOI
"Scared stiff": catatonia as an evolutionary-based fear response.
TL;DR: It is argued that catatonia originally derived from ancestral encounters with carnivores whose predatory instincts were triggered by movement but is now inappropriately expressed in very different modern threat situations.
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TL;DR: The principles of neural science as mentioned in this paper have been used in neural networks for the purpose of neural network engineering and neural networks have been applied in the field of neural networks, such as:
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Does the autistic child have a theory of mind
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