scholarly journals Fear-induced increases in loss aversion are linked to increased neural negative-value coding

2020 ◽  
Vol 15 (6) ◽  
pp. 661-670
Author(s):  
Stefan Schulreich ◽  
Holger Gerhardt ◽  
Dar Meshi ◽  
Hauke R Heekeren
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Loss Aversion ◽  
Neural Mechanism ◽  
Brain Regions ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Fearful Faces ◽  
Value Coding

Abstract Human decisions are often influenced by emotions. An economically relevant example is the role of fear in generating loss aversion. Previous research implicates the amygdala as a key brain structure in the experience of fear and loss aversion. The neural mechanism behind emotional influences on loss aversion is, however, unclear. To address this, we measured brain activation with functional magnetic resonance imaging (fMRI) while participants made decisions about monetary gambles after viewing fearful or neutral faces. We observed that loss aversion following the presentation of neutral faces was mainly predicted by greater deactivations for prospective losses (relative to activations for prospective gains) in several brain regions, including the amygdala. By contrast, increases in loss aversion following the presentation of fearful faces were mainly predicted by greater activations for prospective losses. These findings suggest a fear-induced shift from positive to negative value coding that reflects a context-dependent involvement of distinct valuation processes.

Functional Magnetic Resonance Imaging Study of Thymus Activation Induced by Different Intensity Electrical Stimulation

2021 ◽  
Vol 11 (2) ◽  
pp. 378-385
Author(s):  
Tao Li ◽  
Kai Chen ◽  
Xianyue Quan
Keyword(s):  
Magnetic Resonance Imaging ◽  
Electrical Stimulation ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Brain Regions ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
The Subject ◽  
The Difference

Functional magnetic resonance imaging (fMRI) was used to observe the activation response of the hypothalamus under different intensity electrical stimulation, and to explore the role of thalamus in the pain regulation network. Ten subjects were selected as normal subjects, and 41 °C and 51 °C were performed on the dorsal side of the right forearm of all subjects, respectively. CCHS mission-mode functional magnetic resonance (fMRI) scans (41 °C. CCHS-fMRI group and 51 °C CHS-fMRI group) were pre-processed with fMRI using SPM8. A single sample t-test was used to compare 41 °C CCHS-fMRI group and 51 °C. The CCHS-fMRI group underwent intragroup analysis to observe the activation of brain regions under two different temperature CHS, and recorded the activation intensity of the activation region. A paired t-test was used to explore the difference in activation between the PD group and the control group, and brain regions with statistically significant differences were analyzed. The activation intensity of the activated brain region was recorded, and the cause of the difference was analyzed. At the end of the trial, the visual analog scale (CVAS) was used to score the pain experienced by the subject at the stimulation temperature, and then the subject was subjected to a sensory quantification test (QST), including the measurement of thermal sensation (WS) and thermal pain (HP). At the same time, under the same intensity electrical stimulation, the activation signal of the lateral thalamus was stronger than that of the lateral thalamus, showing a contralateral advantage, while the bilateral thalamus lacked this manifestation. The thalamus should be an important component of the pain-regulating network. This region exhibits a segregationactivated phenomenon, and each region has its own unique stimulatory response characteristics, which helps to understand the role of the thalamus in the treatment of pain information.

scholarly journals Applying 3DPCANet and Functional Magnetic Resonance Imaging to Aided Diagnosis of Alzheimer’s Disease

2021 ◽  
Author(s):  
Yu Wang ◽  
Hongfei Jia ◽  
Yifan Duan ◽  
Hongbing Xiao
Keyword(s):  
Magnetic Resonance Imaging ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Brain Regions ◽  
Support Vector ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Public Data

Abstract Alzheimer's disease (AD) is a progressive neurodegenerative disease, which changes the structure of brain regions by some hidden causes. In this paper for assisting doctors to make correct judgments, an improved 3DPCANet method is proposed to classify AD by combining the mean (mALFF) of the whole brain. The main idea includes that firstly, the functional magnetic resonance imaging (fMRI) data is pre-processed, and mALFF is calculated to get the corresponding matrix. Then the features of mALFF images are extracted via the improved 3DPCANet network. Finally, AD patients with different stages are classified using support vector machine (SVM). Experiments results based on public data from the Alzheimer’s disease neuroimaging initiative (ADNI) show that the proposed approach has better performance compared with state-of-the-art methods. The accuracies of AD vs. significant memory concern (SMC), SMC vs. late mild cognitive impairment (LMCI), and normal control (NC) vs. SMC reach respectively 92.42%, 91.80%, and 89.50%, which testifies the feasibility and effectiveness of the proposed method.

scholarly journals Resting-State Functional Magnetic Resonance Imaging Connectivity Between Semantic and Phonological Regions of Interest May Inform Language Targets in Aphasia

2020 ◽  
Vol 63 (9) ◽  
pp. 3051-3067
Author(s):  
Amy E. Ramage ◽  
Semra Aytur ◽  
Kirrie J. Ballard
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Resting State ◽  
Brain Regions ◽  
Regions Of Interest ◽  
Healthy Controls ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Language Performance

Purpose Brain imaging has provided puzzle pieces in the understanding of language. In neurologically healthy populations, the structure of certain brain regions is associated with particular language functions (e.g., semantics, phonology). In studies on focal brain damage, certain brain regions or connections are considered sufficient or necessary for a given language function. However, few of these account for the effects of lesioned tissue on the “functional” dynamics of the brain for language processing. Here, functional connectivity (FC) among semantic–phonological regions of interest (ROIs) is assessed to fill a gap in our understanding about the neural substrates of impaired language and whether connectivity strength can predict language performance on a clinical tool in individuals with aphasia. Method Clinical assessment of language, using the Western Aphasia Battery–Revised, and resting-state functional magnetic resonance imaging data were obtained for 30 individuals with chronic aphasia secondary to left-hemisphere stroke and 18 age-matched healthy controls. FC between bilateral ROIs was contrasted by group and used to predict Western Aphasia Battery–Revised scores. Results Network coherence was observed in healthy controls and participants with stroke. The left–right premotor cortex connection was stronger in healthy controls, as reported by New et al. (2015) in the same data set. FC of (a) connections between temporal regions, in the left hemisphere and bilaterally, predicted lexical–semantic processing for auditory comprehension and (b) ipsilateral connections between temporal and frontal regions in both hemispheres predicted access to semantic–phonological representations and processing for verbal production. Conclusions Network connectivity of brain regions associated with semantic–phonological processing is predictive of language performance in poststroke aphasia. The most predictive connections involved right-hemisphere ROIs—particularly those for which structural adaptions are known to associate with recovered word retrieval performance. Predictions may be made, based on these findings, about which connections have potential as targets for neuroplastic functional changes with intervention in aphasia. Supplemental Material https://doi.org/10.23641/asha.12735785

scholarly journals How Does Our Brain Process Sugars and Non-Nutritive Sweeteners Differently: A Systematic Review on Functional Magnetic Resonance Imaging Studies

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3010
Author(s):  
Andy Wai Kan Yeung ◽  
Natalie Sui Miu Wong
Keyword(s):  
Magnetic Resonance Imaging ◽  
Systematic Review ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Brain Regions ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Imaging Studies ◽  
Brain Responses ◽  
Fasting Duration

This systematic review aimed to reveal the differential brain processing of sugars and sweeteners in humans. Functional magnetic resonance imaging studies published up to 2019 were retrieved from two databases and were included into the review if they evaluated the effects of both sugars and sweeteners on the subjects’ brain responses, during tasting and right after ingestion. Twenty studies fulfilled the inclusion criteria. The number of participants per study ranged from 5 to 42, with a total number of study participants at 396. Seven studies recruited both males and females, 7 were all-female and 6 were all-male. There was no consistent pattern showing that sugar or sweeteners elicited larger brain responses. Commonly involved brain regions were insula/operculum, cingulate and striatum, brainstem, hypothalamus and the ventral tegmental area. Future studies, therefore, should recruit a larger sample size, adopt a standardized fasting duration (preferably 12 h overnight, which is the most common practice and brain responses are larger in the state of hunger), and reported results with familywise-error rate (FWE)-corrected statistics. Every study should report the differential brain activation between sugar and non-nutritive sweetener conditions regardless of the complexity of their experiment design. These measures would enable a meta-analysis, pooling data across studies in a meaningful manner.

scholarly journals Cerebral Functional Magnetic Resonance Imaging Activation Modulated by a Single Dose of the Monoamine Neurotransmission Enhancers Fluoxetine and Fenozolone during Hand Sensorimotor Tasks

1999 ◽  
Vol 19 (12) ◽  
pp. 1365-1375 ◽  
Author(s):  
Isabelle Loubinoux ◽  
Keder Boulanouar ◽  
Jean-Philippe Ranjeva ◽  
Christophe Carel ◽  
Isabelle Berry ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Single Dose ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Motor Activity ◽  
Healthy Subjects ◽  
Drug Effects ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

Fluoxetine inhibits the reuptake of serotonin, and dextroamphetamine enhances presynaptic release of monoamines. Although the excitatory effect of both noradrenaline and dopamine on motor behavior generally is accepted, the role of serotonin on motor output is under debate. In the current investigation, the authors evidenced a putative role of monoamines and, more specifically, of serotonin in the regulation of cerebral motor activity in healthy subjects. The effects on cerebral motor activity of a single dose of fluoxetine (20 mg), an inhibitor of serotonin reuptake, and fenozolone (20 mg/50 kg), an amphetamine-like drug, were assessed by functional magnetic resonance imaging. Subjects performed sensorimotor tasks with the right hand. Functional magnetic resonance imaging studies were performed in two sessions on two different days. The first session, with two scan experiments separated by 5 hours without any drug administration, served as time-effect control. A second, similar session but with drug administration after the first scan assessed drug effects. A large increase in evoked signal intensity occurred in the ipsilateral cerebellum, and a parallel, large reduction occurred in primary and secondary motor cortices (P < 10–3). These results are consistent with the known effects of habituation. Both drugs elicited comparable effects, that is, a more focused activation in the contralateral sensorimotor area, a greater involvement of posterior supplementary motor area, and a widespread decrease of bilateral cerebellar activation (P < 10–3). The authors demonstrated for the first time that cerebral motor activity can be modulated by a single dose of fluoxetine or fenozolone in healthy subjects. Drug effects demonstrated a direct or indirect involvement of monoamines and serotonin in the facilitation of cerebral motor activity.

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