scholarly journals Meet me in the middle: brain-behavior mediation analysis for fMRI experiments

2020 ◽  
Author(s):  
Jules Brochard ◽  
Jean Daunizeau
Keyword(s):  
Mediation Analysis ◽  
Statistical Tests ◽  
Brain Regions ◽  
Computationally Efficient ◽  
Information Theoretic ◽  
Decision Under Risk ◽  
Specificity And Sensitivity ◽  
Fmri Study ◽  
Brain Behavior ◽  
External Stimuli

AbstractFunctional outcomes (e.g., subjective percepts, emotions, memory retrievals, decisions, etc…) are partly determined by external stimuli and/or cues. But they may also be strongly influenced by (trial-by-trial) uncontrolled variations in brain responses to incoming information. In turn, this variability provides information regarding how stimuli and/or cues are processed by the brain to shape behavioral responses. This can be exploited by brain-behavior mediation analysis to make specific claims regarding the contribution of brain regions to functionally-relevant input-output transformations. In this work, we address four challenges of this type of approach, when applied in the context of mass-univariate fMRI data analysis: (i) we quantify the specificity and sensitivity profiles of different variants of mediation statistical tests, (ii) we evaluate their robustness to hemo-dynamic and other confounds, (iii) we identify the sorts of brain mediators that one can expect to detect, and (iv) we disclose possible interpretational issues and address them using complementary information-theoretic approaches. En passant, we propose a computationally efficient algorithmic implementation of the approach that is amenable to whole-brain exploratory analysis. We also demonstrate the strengths and weaknesses of brain-behavior mediation analysis in the context of an fMRI study of decision under risk. Finally, we discuss the limitations and possible extensions of the approach.

scholarly journals Adaptive stimulus selection for multi-alternative psychometric functions with lapses

2018 ◽  
Author(s):  
Ji Hyun Bak ◽  
Jonathan W. Pillow
Keyword(s):  
Multinomial Logistic Regression ◽  
Stimulus Selection ◽  
Selection Methods ◽  
Computationally Efficient ◽  
Information Theoretic ◽  
Building Models ◽  
Speed Up ◽  
Selection For ◽  
Regression Mixture ◽  
External Stimuli

Psychometric functions (PFs) quantify how external stimuli affect behavior and play an important role in building models of sensory and cognitive processes. Adaptive stimulus selection methods seek to select stimuli that are maximally informative about the PF given data observed so far in an experiment and thereby reduce the number of trials required to estimate the PF. Here we develop new adaptive stimulus selection methods for flexible PF models in tasks with two or more alternatives. We model the PF with a multinomial logistic regression mixture model that incorporates realistic aspects of psychophysical behavior, including lapses and multiple alternatives for the response. We propose an information-theoretic criterion for stimulus selection and develop computationally efficient methods for inference and stimulus selection based on semi-adaptive Markov Chain Monte Carlo (MCMC) sampling. We apply these methods to data from macaque monkeys performing a multi-alternative motion discrimination task, and show in simulated experiments that our method can achieve a substantial speed-up over random designs. These advances will reduce the data needed to build accurate models of multi-alternative PFs and can be extended to high-dimensional PFs that would be infeasible to characterize with standard methods.

Comparação de testes coproparasitológicos em criadouro comercial de psitacídeos exóticos

2020 ◽  
Vol 3 (5) ◽  
pp. 100-107
Author(s):  
Marina Camargo de Sousa ◽  
◽  
Julia Ronzani Vial ◽  
Rodrigo Hidalgo Friciello Teixeira ◽  
Andrea Cristina Higa Nakaghi ◽  
...  
Keyword(s):  
Statistical Tests ◽  
Companion Animals ◽  
Clinical Importance ◽  
Breeding Site ◽  
Chi Square ◽  
Fecal Samples ◽  
Breeding Sites ◽  
Specificity And Sensitivity ◽  
Nematode Eggs ◽  
Commercial Breeding

Birds of the psittaciform order, composed by the Psittacidae and Loridae family have several characteristics making them more frequently kept as companion animals, promoting the increase of breeding sites in Brazil. The present study aimed to analyze the specificity and sensitivity of three different coproparasitological tests, Willis, Hoffman and Direto de feces, through statistical tests: Chi-Square and Kappa. 70 fecal samples of exotic parrots were collected from a commercial breeding site and these were submitted to the three tests, totaling 210 coproparasitological exams. Among the tests performed, 29,5% were positive for nematode eggs, cestodes and oocysts. Coproparasitological exams are inexpensive, have clinical importance, indicating the population of endoparasites and therapeutic treatments.

scholarly journals Peripheral arterial stiffness during electrocutaneous stimulation is positively correlated with pain-related brain activity and subjective pain intensity: an fMRI study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshio Tsuji ◽  
Fumiya Arikuni ◽  
Takafumi Sasaoka ◽  
Shin Suyama ◽  
Takashi Akiyoshi ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Pain Intensity ◽  
Brain Activity ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Electrocutaneous Stimulation ◽  
Pain Matrix ◽  
Fmri Study ◽  
Subjective Pain ◽  
Peripheral Arterial

AbstractBrain activity associated with pain perception has been revealed by numerous PET and fMRI studies over the past few decades. These findings helped to establish the concept of the pain matrix, which is the distributed brain networks that demonstrate pain-specific cortical activities. We previously found that peripheral arterial stiffness $${\beta }_{\text{art}}$$ β art responds to pain intensity, which is estimated from electrocardiography, continuous sphygmomanometer, and photo-plethysmography. However, it remains unclear whether and to what extent $${\beta }_{\text{art}}$$ β art aligns with pain matrix brain activity. In this fMRI study, 22 participants received different intensities of pain stimuli. We identified brain regions in which the blood oxygen level-dependent signal covaried with $${\beta }_{\text{art}}$$ β art using parametric modulation analysis. Among the identified brain regions, the lateral and medial prefrontal cortex and ventral and dorsal anterior cingulate cortex were consistent with the pain matrix. We found moderate correlations between the average activities in these regions and $${\beta }_{\text{art}}$$ β art (r = 0.47, p < 0.001). $${\beta }_{\text{art}}$$ β art was also significantly correlated with self-reported pain intensity (r = 0.44, p < 0.001) and applied pain intensity (r = 0.43, p < 0.001). Our results indicate that $${\beta }_{\text{art}}$$ β art is positively correlated with pain-related brain activity and subjective pain intensity. This study may thus represent a basis for adopting peripheral arterial stiffness as an objective pain evaluation metric.

Distinguishing hypochondriasis and schizophrenia using regional homogeneity: a resting-state fMRI study and support vector machine analysis

2021 ◽  
pp. 1-29
Author(s):  
Kangyu Jin ◽  
Zhe Shen ◽  
Guoxun Feng ◽  
Zhiyong Zhao ◽  
Jing Lu ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Resting State ◽  
Parietal Lobe ◽  
Brain Activity ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Regional Homogeneity ◽  
Middle Temporal Gyrus ◽  
Support Vector ◽  
Fmri Study

Abstract Objective: A few former studies suggested there are partial overlaps in abnormal brain structure and cognitive function between Hypochondriasis (HS) and schizophrenia (SZ). But their differences in brain activity and cognitive function were unclear. Methods: 21 HS patients, 23 SZ patients, and 24 healthy controls (HC) underwent Resting-state functional magnetic resonance imaging (rs-fMRI) with the regional homogeneity analysis (ReHo), subsequently exploring the relationship between ReHo value and cognitive functions. The support vector machines (SVM) were used on effectiveness evaluation of ReHo for differentiating HS from SZ. Results: Compared with HC, HS showed significantly increased ReHo values in right middle temporal gyrus (MTG), left inferior parietal lobe (IPL) and right fusiform gyrus (FG), while SZ showed increased ReHo in left insula, decreased ReHo values in right paracentral lobule. Additionally, HS showed significantly higher ReHo values in FG, MTG and left paracentral lobule but lower in insula than SZ. The higher ReHo values in insula were associated with worse performance in MCCB in HS group. SVM analysis showed a combination of the ReHo values in insula and FG was able to satisfactorily distinguish the HS and SZ patients. Conclusion: our results suggested the altered default mode network (DMN), of which abnormal spontaneous neural activity occurs in multiple brain regions, might play a key role in the pathogenesis of HS, and the resting-state alterations of insula closely related to cognitive dysfunction in HS. Furthermore, the combination of the ReHo in FG and insula was a relatively ideal indicator to distinguish HS from SZ.

scholarly journals An fMRI study of scientists with a Ph.D. in physics confronted with naive ideas in science

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Geneviève Allaire-Duquette ◽  
Lorie-Marlène Brault Foisy ◽  
Patrice Potvin ◽  
Martin Riopel ◽  
Marilyne Larose ◽  
...  
Keyword(s):  
Inhibitory Control ◽  
Conceptual Understanding ◽  
Matched Control ◽  
Brain Regions ◽  
Scientific Training ◽  
Frontal Brain ◽  
Fmri Study ◽  
Lower Accuracy ◽  
Neuroimaging Study ◽  
Scientific Value

AbstractA central challenge in developing conceptual understanding in science is overcoming naive ideas that contradict the content of science curricula. Neuroimaging studies reveal that high school and university students activate frontal brain areas associated with inhibitory control to overcome naive ideas in science, probably because they persist despite scientific training. However, no neuroimaging study has yet explored how persistent naive ideas in science are. Here, we report brain activations of 25 scientists with a Ph.D. in physics assessing the scientific value of naive ideas in science. Results show that scientists are slower and have lower accuracy when judging the scientific value of naive ideas compared to matched control ideas. fMRI data reveals that a network of frontal brain regions is more activated when judging naive ideas. Results suggest that naive ideas are likely to persist, even after completing a Ph.D. Advanced experts may still rely on high order executive functions like inhibitory control to overcome naive ideas when the context requires it.

scholarly journals Comparação de testes coproparasitológicos em criadouro comercial de psitacídeos exóticos

2020 ◽  
Vol 3 (5) ◽  
pp. 100-107
Author(s):  
Marina Camargo de Sousa ◽  
◽  
Julia Ronzani Vial ◽  
Rodrigo Hidalgo Friciello Teixeira ◽  
Andrea Cristina Higa Nakaghi ◽  
...  
Keyword(s):  
Statistical Tests ◽  
Companion Animals ◽  
Clinical Importance ◽  
Breeding Site ◽  
Chi Square ◽  
Fecal Samples ◽  
Breeding Sites ◽  
Specificity And Sensitivity ◽  
Nematode Eggs ◽  
Commercial Breeding

Birds of the psittaciform order, composed by the Psittacidae and Loridae family have several characteristics making them more frequently kept as companion animals, promoting the increase of breeding sites in Brazil. The present study aimed to analyze the specificity and sensitivity of three different coproparasitological tests, Willis, Hoffman and Direto de feces, through statistical tests: Chi-Square and Kappa. 70 fecal samples of exotic parrots were collected from a commercial breeding site and these were submitted to the three tests, totaling 210 coproparasitological exams. Among the tests performed, 29,5% were positive for nematode eggs, cestodes and oocysts. Coproparasitological exams are inexpensive, have clinical importance, indicating the population of endoparasites and therapeutic treatments.

scholarly journals Lynn_etal_MathSkills_CPM_Preprint_V1_05July2021

2021 ◽  
Author(s):  
Andrew Lynn ◽  
Eric D. Wilkey ◽  
Gavin Price
Keyword(s):  
Functional Connectivity ◽  
Predictive Modeling ◽  
Brain Connectivity ◽  
Network Connectivity ◽  
Brain Regions ◽  
Math Skills ◽  
Whole Brain ◽  
Building Models ◽  
State Dependent ◽  
Brain Behavior

The human brain comprises multiple canonical networks, several of which are distributed across frontal, parietal, and temporooccipital regions. Studies report both positive and negative correlations between children’s math skills and the strength of functional connectivity among these regions during math-related tasks and at rest. Yet, it is unclear how the relation between children’s math skills and functional connectivity map onto patterns of distributed whole-brain connectivity, canonical network connectivity, and whether these relations are consistent across different task-states. We used connectome-based predictive modeling to test whether functional connectivity during number comparison and at rest predicts children’s math skills (N=31, Mage=9.21years) using distributed whole-brain connections versus connections among canonical networks. We found that weaker connectivity distributed across the whole brain and weaker connectivity between key math-related brain regions in specific canonical networks predicts better math skills in childhood. The specific connections predicting math skills, and whether they were distributed or mapped onto canonical networks, varied between tasks, suggesting that state-dependent rather than trait-level functional network architectures support children’s math skills. Furthermore, the current predictive modeling approach moves beyond brain-behavior correlations and toward building models of brain connectivity that may eventually aid in predicting future math skills.

scholarly journals Methodological Considerations in Conducting an Olfactory fMRI Study

2013 ◽  
Vol 27 (3) ◽  
pp. 267-276 ◽  
Author(s):  
Faezeh Vedaei ◽  
Mohammad Fakhri ◽  
Mohammad Hossein Harirchian ◽  
Kavous Firouznia ◽  
Yones Lotfi ◽  
...  
Keyword(s):  
Functional Neuroimaging ◽  
Neurological Diseases ◽  
Brain Regions ◽  
Brain Network ◽  
Functional Brain Imaging ◽  
Behavioral Studies ◽  
Fmri Study ◽  
Methodological Considerations ◽  
Technical Principles ◽  
Review Current

The sense of smell is a complex chemosensory processing in human and animals that allows them to connect with the environment as one of their chief sensory systems. In the field of functional brain imaging, many studies have focused on locating brain regions that are involved during olfactory processing. Despite wealth of literature about brain network in different olfactory tasks, there is a paucity of data regarding task design. Moreover, considering importance of olfactory tasks for patients with variety of neurological diseases, special contemplations should be addressed for patients. In this article, we review current olfaction tasks for behavioral studies and functional neuroimaging assessments, as well as technical principles regarding utilization of these tasks in functional magnetic resonance imaging studies.

scholarly journals C-19 An fMRI Study of Age-Associated Changes in Basic Visual Discrimination

2019 ◽  
Vol 34 (6) ◽  
pp. 1048-1048
Author(s):  
T Seider ◽  
E Porges ◽  
A Woods ◽  
R Cohen
Keyword(s):  
Visual Processing ◽  
Visual Discrimination ◽  
Community Sample ◽  
Visual Assessment ◽  
Brain Regions ◽  
Brain Response ◽  
Match To Sample ◽  
Fmri Study ◽  
Perceptual Skill ◽  
Cluster Level

Abstract Objective The study was conducted to determine age-associated changes in functional brain response, measured with fMRI, during visual discrimination with regard to three elementary components of visual perception: shape, location, and velocity. A secondary aim was to validate the method used to isolate the hypothesized brain regions associated with these perceptual functions. Method Items from the Visual Assessment Battery (VAB), a simultaneous match-to-sample task, assessed visual discrimination in 40 healthy adults during fMRI. Participants were aged 51-91 and recruited from a larger community sample for a study on normal aging. The tasks were designed to isolate neural recruitment during discrimination of either location, shape, or velocity by using tasks that were identical aside from the perceptual skill required to complete them. Results The Location task uniquely activated the dorsal visual processing stream, the Shape task the ventral stream, and the Velocity task V5/MT. Greater age was associated with greater neural recruitment, particularly in frontal areas (uncorrected voxel-level p < .001, family-wise error cluster-level p□.05). Conclusions Results validated the specialization of brain regions for spatial, perceptual, and movement discriminations and the use of the VAB to assess functioning localized to these regions. Anterior neural recruitment during visual discrimination increases with age.

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