scholarly journals Towards a functional neuroanatomy of conscious perception and its modulation by volition: implications of human auditory neuroimaging studies

1998 ◽  
Vol 353 (1377) ◽  
pp. 1883-1888 ◽  
Author(s):  
◽  
D. A. Silbersweig ◽  
E. Stern
Keyword(s):  
Functional Neuroimaging ◽  
Brain Activity ◽  
Neural Substrates ◽  
Functional Neuroanatomy ◽  
Subcortical Structures ◽  
Sensory Stimuli ◽  
Sensory Awareness ◽  
Positron Emission ◽  
Neuroimaging Techniques

Conscious sensory perception and its modulation by volition are integral to human mental life. Functional neuroimaging techniques provide a direct means of identifying and characterizing in vivo the systems-level patterns of brain activity associated with such mental functions. In a series of positron emission tomography activation experiments, we and our colleagues have examined a range of normal and abnormal auditory states that, when contrasted, provide dissociations relevant to the question of the neural substrates of sensory awareness. These dissociations include sensory awareness in the presence and absence of external sensory stimuli, the transition from sensory unawareness to awareness (or vice versa) in the presence of sensory stimuli, and sensory awareness with and without volition. The auditory states studied include hallucinations, mental imagery, cortical deafness modulated by attention, and hearing modulated by sedation. The results of these studies highlight the distributed nature of the functional neuroanatomy that is sufficient, if not necessary, for sensory awareness. The probable roles of unimodal association (as compared with primary) cortices, heteromodal cortices, limbic/paralimbic regions and subcortical structures (such as the thalamus) are discussed. In addition, interactions between pre– and post–rolandic regions are examined in the context of top–down, volitional modulation of sensory awareness.

scholarly journals Imaging the Functional Neuroanatomy of Parkinson’s Disease: Clinical Applications and Future Directions

2021 ◽  
Vol 18 (5) ◽  
pp. 2356
Author(s):  
Fulvio Lauretani ◽  
Yari Longobucco ◽  
Giulia Ravazzoni ◽  
Elena Gallini ◽  
Marco Salvi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Single Photon ◽  
Photon Emission ◽  
Pathological Process ◽  
Emission Computed Tomography ◽  
Functional Neuroanatomy ◽  
Positron Emission ◽  
Neuroimaging Techniques

The neurobiology of Parkinson’s disease and its progression has been investigated during the last few decades. Braak et al. proposed neuropathological stages of this disease based on the recognizable topographical extent of Lewy body lesions. This pathological process involves specific brain areas with an ascending course from the brain stem to the cortex. Post-mortem studies are of importance to better understand not only the progression of motor symptoms, but also the involvement of other domains, including cognition and behavior. The correlation between the neuropathological expansion of the disease and the clinical phases remains demanding. Neuroimaging, including magnetic resonance imaging (MRI), positron emission tomography (PET), and single photon emission computed tomography (SPECT), could help to bridge this existing gap by providing in vivo evidence of the extension of the disorders. In the last decade, we observed an overabundance of reports regarding the sensitivity of neuroimaging techniques. All these studies were aimed at improving the accuracy of Parkinson’s disease (PD) diagnosis and discriminating it from other causes of parkinsonism. In this review, we look at the recent literature concerning PD and address the new frontier of diagnostic accuracy in terms of identification of early stages of the disease and conventional neuroimaging techniques that, in vivo, are capable of photographing the basal ganglia network and its cerebral connections.

scholarly journals Meditation and the Brain in Health and Disease

2020 ◽  
Author(s):  
Kieran C. R. Fox ◽  
B. Rael Cahn
Keyword(s):  
Cognitive Aging ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Well Being ◽  
Neural Substrates ◽  
Human Cognition ◽  
Psychiatric Disease ◽  
Positron Emission ◽  
Health And Disease ◽  
Pet Scans

The aim of this chapter is to provide an accessible introduction to the neuroscience of meditation. First, a review of studies examining the relationship between meditation and alterations in the structure of the brain’s grey and white matter (so-called morphometric neuroimaging) is offered. Next, the chapter discusses findings from functional neuroimaging methods, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) scans, and what they have taught us about the brain’s patterns of activity during different forms of meditation, how meditation alters the brain’s response to various tasks and experiences, and how the expertise of long-term meditators might be harnessed to help us explore subtle aspects of human cognition. Third, the chapter reviews electrophysiological methods of measuring brain activity during meditation, such as electroencephalography (EEG), and how these findings relate to what we have learned from morphometric and functional neuroimaging. Finally, there is a discussion of the implications of this research and of meditation more generally for brain health and psychological well-being. Specifically, the discussion focuses on how meditation might offset the deficits related to cognitive aging, as well as help ameliorate the symptoms and underlying neural substrates associated with neurodegenerative and psychiatric disease.

scholarly journals Meditation and the brain in health and disease

2018 ◽  
Author(s):  
Kieran Fox ◽  
B. Rael Cahn
Keyword(s):  
Cognitive Aging ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Well Being ◽  
Neural Substrates ◽  
Human Cognition ◽  
Psychiatric Disease ◽  
Positron Emission ◽  
Health And Disease ◽  
Pet Scans

The aim of this chapter is to provide an accessible introduction to the neuroscience of meditation. First, we review studies examining the relationship between meditation and alterations in the structure of the brain’s grey and white matter (so-called morphometric neuroimaging). Next, we discuss findings from functional neuroimaging methods, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) scans, and what they have taught us about the brain’s patterns of activity during different forms of meditation, how meditation alters the brain’s response to various tasks and experiences, and how the expertise of long-term meditators might be harnessed to help us explore subtle aspects of human cognition. Third, we review electrophysiological methods of measuring brain activity during meditation, such as electroencephalography (EEG), and how these findings relate to what we have learned from morphometric and functional neuroimaging. Finally, we discuss the implications of this research and of meditation more generally for brain health and psychological well-being. Specifically, we focus on how meditation might ameliorate the deficits related to cognitive aging, as well as help ameliorate the symptoms and underlying neural substrates associated with neurodegenerative and psychiatric disease.

scholarly journals Diagnosis of Parkinson’s Disease. Part 1. The Potential of Functional Neuroimaging

Doctor Ru ◽  
2020 ◽  
Vol 19 (9) ◽  
pp. 6-12
Author(s):  
M.R. Sapronova ◽  
◽  
D.V. Dmitrenko ◽  
N.A. Schnaider ◽  
A.A. Molgachev ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Functional Neuroimaging ◽  
Single Photon ◽  
Photon Emission ◽  
Transcranial Sonography ◽  
Emission Computed Tomography ◽  
Resonance Spectroscopy ◽  
Positron Emission ◽  
Neuroimaging Techniques

Objective of the Review: To describe available functional neuroimaging techniques for use in patients with Parkinson’s disease (PD). Key Points: Parkinson’s disease is a neurodegenerative disorder which affects 2-3% of people older than 65 years. The main neuropathological hallmarks of PD are an accumulation of alpha-synuclein aggregates in the cellular cytoplasm and a loss of neurons in the pars compacta of the substantia nigra, leading to dopamine deficiency. Clinical symptoms of the disease appear when the underlying neural impairment is already advanced, which significantly reduces treatment options. Over the two last decades, functional neuroimaging techniques such as positron emission tomography, single-photon emission computed tomography, proton magnetic resonance spectroscopy, and transcranial sonography have increasingly been used for diagnosing PD during patients’ lifetime and understanding the neuropathological mechanisms and compensatory reactions underlying its symptoms, as well as for monitoring the progression of PD. Conclusion: Modern functional neuroimaging techniques not only facilitate differential diagnosis of PD, but also make it possible to detect the disease at its early/preclinical stage. Keywords: Parkinson’s disease, neuroimaging, positron emission tomography, single-photon emission computed tomography, proton magnetic resonance spectroscopy, transcranial sonography.

scholarly journals Functional neuroimaging studies of the effects of psychotherapy

2014 ◽  
Vol 16 (1) ◽  
pp. 75-81 ◽  
Keyword(s):  
Functional Neuroimaging ◽  
Brain Activity ◽  
Behavioral Changes ◽  
Neural Mechanisms ◽  
Psychological Interventions ◽  
Emotional States ◽  
Major Depressive ◽  
Psychotherapeutic Interventions ◽  
Functional Brain Activity ◽  
Neuroimaging Techniques

It has been long established that psychological interventions can markedly alter patients' thinking patterns, beliefs, attitudes, emotional states, and behaviors. Little was known about the neural mechanisms mediating such alterations before the advent of functional neuroimaging techniques. Since the turn of the new millenium, several functional neuroimaging studies have been conducted to tackle this important issue. Some of these studies have explored the neural impact of various forms of psychotherapy in individuals with major depressive disorder. Other neuroimaging studies have investigated the effects of psychological interventions for anxiety disorders. I review these studies in the present article, and discuss the putative neural mechanisms of change in psychotherapy. The findings of these studies suggest that mental and behavioral changes occurring during psychotherapeutic interventions can lead to a normalization of functional brain activity at a global level.

scholarly journals Measurement of Changes in Opioid Receptor Binding in Vivo During Trigeminal Neuralgic Pain Using [11C]Diprenorphine and Positron Emission Tomography

1999 ◽  
Vol 19 (7) ◽  
pp. 803-808 ◽  
Author(s):  
Anthony K. P. Jones ◽  
Niel D. Kitchen ◽  
Hiroshi Watabe ◽  
Vincent J. Cunningham ◽  
Terry Jones ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Volume Of Distribution ◽  
Emission Tomography ◽  
Subcortical Structures ◽  
Endogenous Opioid ◽  
Positron Emission ◽  
Before And After ◽  
Pain State ◽  
Parietal Cortices

The binding of [11C]diprenorphine to µ, κ, and Δ subsites in cortical and subcortical structures was measured by positron emission tomography in vivo in six patients before and after surgical relief of trigeminal neuralgia pain. The volume of distribution of [11C]diprenorphine binding was significantly increased after thermocoagulation of the relevant trigeminal division in the following areas: prefrontal, insular, perigenual, mid-cingulate and inferior parietal cortices, basal ganglia, and thalamus bilaterally. In addition to the pain relief associated with the surgical procedure, there also was an improvement in anxiety and depression scores. In the context of other studies, these changes in binding most likely resulted from the change in the pain state. The results suggest an increased occupancy by endogenous opioid peptides during trigeminal pain but cannot exclude coexistent down-regulation of binding sites.

scholarly journals Functional neuroimaging of psychiatric disorders: exploring hidden behaviour

2004 ◽  
Vol 34 (4) ◽  
pp. 577-581 ◽  
Author(s):  
P. C. FLETCHER
Keyword(s):  
Functional Neuroimaging ◽  
Brain Activity ◽  
Cognitive Strategies ◽  
Healthy Person ◽  
Brain Regions ◽  
Task Demands ◽  
Unrealistic Expectation ◽  
Positron Emission ◽  
The Impact ◽  
Function Mapping

From the outset, people have had high expectations of functional neuroimaging. Many will have been disappointed. After roughly a decade of widespread use, even an enthusiastic advocate must be diffident about the impact of the two most frequently used techniques – positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) – upon clinical psychiatry. Perhaps this disappointment arises from an unrealistic expectation of what these techniques are able to tell us about the workings of the normal and the disordered brain. Anyone who hoped for intricate and unambiguous region-to-function mapping was always going to be disappointed. This expectation presupposes, among other things, a thorough understanding of the cognitive functions that are to be mapped onto the brain regions. This understanding, however, while developing, is still rudimentary. Mapping disorder along comparable lines is even more complex since it demands two levels of understanding. The first is of the healthy region-to-function mapping, the second of the disordered region-to-function mapping, which immediately demands a consideration of the nature of the function in the disordered state. After all, someone with schizophrenia, when confronted with a psychological task, might tackle it in a very different way, in terms of the cognitive strategies used, from a healthy person confronted with the same task. The observation that brain activity differs across the two individuals would only be interpretable insofar as one thoroughly understood the processes that each individual invoked in response to the task demands.

scholarly journals Translating the hemodynamic response: why focused interdisciplinary integration should matter for the future of functional neuroimaging

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6621 ◽  
Author(s):  
Sigita Cinciute
Keyword(s):  
Functional Neuroimaging ◽  
Hemodynamic Response ◽  
Cellular Biology ◽  
Brain Functioning ◽  
Scientific Discussion ◽  
Brain Physiology ◽  
Physiological Phenomenon ◽  
Critical Overview ◽  
Neuroimaging Techniques

The amount of information acquired with functional neuroimaging techniques, particularly fNIRS and fMRI, is rapidly growing and has enormous potential for studying human brain functioning. Therefore, many scientists focus on solving computational neuroimaging and Big Data issues to advance the discipline. However, the main obstacle—the accurate translation of the hemodynamic response (HR) by the investigation of a physiological phenomenon called neurovascular coupling—is still not fully overcome and, more importantly, often overlooked in this context. This article provides a brief and critical overview of significant findings from cellular biology and in vivo brain physiology with a focus on advancing existing HR modelling paradigms. A brief historical timeline of these disciplines of neuroscience is presented for readers to grasp the concept better, and some possible solutions for further scientific discussion are provided.

scholarly journals Measuring Endogenous 5-HT Release by Emission Tomography: Promises and Pitfalls

2010 ◽  
Vol 30 (10) ◽  
pp. 1682-1706 ◽  
Author(s):  
Louise M Paterson ◽  
Robin J Tyacke ◽  
David J Nutt ◽  
Gitte M Knudsen
Keyword(s):  
Emission Tomography ◽  
Basic Knowledge ◽  
Binding Potential ◽  
Endogenous Dopamine ◽  
Positron Emission ◽  
Serotonin Reuptake Transporter ◽  
Endogenous Dopamine Release ◽  
Receptor Targets ◽  
Neuroimaging Techniques

Molecular in vivo neuroimaging techniques can be used to measure regional changes in endogenous neurotransmitters, evoked by challenges that alter synaptic neurotransmitter concentration. This technique has most successfully been applied to the study of endogenous dopamine release using positron emission tomography, but has not yet been adequately extended to other neurotransmitter systems. This review focuses on how the technique has been applied to the study of the 5-hydroxytryptamine (5-HT) system. The principles behind visualising fluctuations in neurotransmitters are introduced, with reference to the dopaminergic system. Studies that aim to image acute, endogenous 5-HT release or depletion at 5-HT receptor targets are summarised, with particular attention to studies in humans. Radiotracers targeting the 5-HT1A, 5-HT2A, and 5-HT4 receptors and the serotonin reuptake transporter have been explored for their sensitivity to 5-HT fluctuations, but with mixed outcomes; tracers for these targets cannot reliably image endogenous 5-HT in humans. Shortcomings in our basic knowledge of the mechanisms underlying changes in binding potential are addressed, and suggestions are made as to how the selection of targets, radiotracers, challenge paradigms, and experimental design might be optimised to improve our chances of successfully imaging endogenous neurotransmitters in the future.

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