Differential roles of polar orbital prefrontal cortex and parietal lobes in logical reasoning with neutral and negative emotional content

To answer the question of how brain pathology affects reasoning about negative emotional content, we administered a disjunctive logical reasoning task involving arguments with neutral content (e.g. Either there are tigers or women in NYC, but not both; There are no tigers in NYC; There are women in NYC) and emotionally laden content (e.g. Either there are pedophiles or politicians in Texas, but not both; There are politicians in Texas; There are no pedophiles in Texas) to 92 neurological patients with focal lesions to various parts of the brain. A Voxel Lesion Symptom Mapping (VLSM) analysis identified 16 patients, all with lesions to the orbital polar prefrontal cortex (BA 10 & 11), as being selectively impaired in the emotional reasoning condition. Another 17 patients, all with lesions to the parietal cortex, were identified as being impaired in the neutral content condition. The reasoning scores of these two patient groups, along with 23 matched normal controls, underwent additional analysis to explore the effect of belief bias. This analysis revealed that the differences identified above were largely driven by trials where there was an incongruency between the believability of the conclusion and the validity of the argument (i.e. valid argument /false conclusion or invalid argument /true conclusion). Patients with lesions to polar orbital prefrontal cortex underperformed in incongruent emotional content trials and over performed in incongruent neutral content trials (compared to both normal controls and patients with parietal lobe lesions). Patients with lesions to parietal lobes underperformed normal controls (at a trend level) in neutral trials where there was a congruency between the believability of the conclusion and the validity of the argument (i.e. valid argument/true conclusion or invalid argument/false conclusion). We conclude that lesions to the polar orbital prefrontal cortex (i) prevent these patients from enjoying any emotionally induced cognitive boost, and (ii) block the belief bias processing route in the neutral condition. Lesions to parietal lobes result in a generalized impairment in logical reasoning with neutral content

Differential roles of polar orbital prefrontal cortex and parietal lobes in logical reasoning with neutral and negative emotional content

To answer the question of how brain pathology affects reasoning about negative emotional content, we administered a disjunctive logical reasoning task involving arguments with neutral content (e.g. Either there are tigers or women in NYC, but not both; There are no tigers in NYC; There are women in NYC) and emotionally laden content (e.g. Either there are pedophiles or politicians in Texas, but not both; There are politicians in Texas; There are no pedophiles in Texas) to 92 neurological patients with focal lesions to various parts of the brain. A Voxel Lesion Symptom Mapping (VLSM) analysis identified 16 patients, all with lesions to the orbital polar prefrontal cortex (BA 10 & 11), as being selectively impaired in the emotional reasoning condition. Another 17 patients, all with lesions to the parietal cortex, were identified as being impaired in the neutral content condition. The reasoning scores of these two patient groups, along with 23 matched normal controls, underwent additional analysis to explore the effect of belief bias. This analysis revealed that the differences identified above were largely driven by trials where there was an incongruency between the believability of the conclusion and the validity of the argument (i.e. valid argument /false conclusion or invalid argument /true conclusion). Patients with lesions to polar orbital prefrontal cortex underperformed in incongruent emotional content trials and over performed in incongruent neutral content trials (compared to both normal controls and patients with parietal lobe lesions). Patients with lesions to parietal lobes underperformed normal controls (at a trend level) in neutral trials where there was a congruency between the believability of the conclusion and the validity of the argument (i.e. valid argument/true conclusion or invalid argument/false conclusion). We conclude that lesions to the polar orbital prefrontal cortex (i) prevent these patients from enjoying any emotionally induced cognitive boost, and (ii) block the belief bias processing route in the neutral condition. Lesions to parietal lobes result in a generalized impairment in logical reasoning with neutral content

Is the Relation Between the Solar Wind Dynamic Pressure and the Magnetopause Standoff Distance so Straightforward?

We present results of global magnetohydrodynamic simulations which reconsider the relationship between the solar wind dynamic pressure (Pd) and magnetopause standoff distance (RSUB). We simulate the magnetospheric response to increases in the dynamic pressure by varying separately the solar wind density or velocity for northward and southward interplanetary magnetic field (IMF). We obtain different values of the power law indices N in the relation RSUB- ¼Pd- 1/N depending on which parameter, density, or velocity, has been varied and for which IMF orientation. The changes in the standoff distance are smaller (higher N) for a density increase for southward IMF and greater (smaller N) for a velocity increase. An enhancement of the solar wind velocity for a southward IMF increases the magnetopause reconnection rate and Region 1 current that move the magnetopause closer to the Earth than it appears in the case of density increase for the same dynamic pressure.Plain Language SummaryThe magnetopause is the boundary between the near- Earth space, which is governed by the magnetic field produced in the Earth’s core, and interplanetary space populated by the plasma emitted from the Sun called the solar wind. It is well known that the position of this boundary is defined by the balance of the pressures from both sides of the magnetopause and in a unique way depends on the velocity and density of the plasma in the interplanetary space. In this work, we reexamine the relationship between the magnetopause position and parameters of the solar wind by means of computer modeling. It is shown that the relationship between solar wind velocity and density and magnetopause position is more complex than originally thought. It is suggested that the pressure balance condition through the magnetopause depends on the continuing magnetic reconnection between the interplanetary and magnetospheric magnetic field lines and that the consequences of the reconnection change the relationship between the solar wind dynamic pressure and magnetopause boundary location.Key PointsWe reconsider the relation between the solar wind dynamic pressure and magnetopause standoff distanceThe magnetopause reacts differently to density, and velocity increases for the same dynamic pressureA new scaling law for magnetopause standoff distance is proposedPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154966/1/grl60461_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154966/2/grl60461.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154966/3/grl60461-sup-0001-Supporting_Information_SI-S01.pd

The nature and origin of Seyfert warm absorbers

We collate the results of recent high resolution X-ray spectroscopic observations of 23 AGN, and use the resulting information to try to provide answers to some of the main open questions about warm absorbers: where do they originate, what effect do they have on their host galaxies, and what is their importance within the energetics and dynamics of the AGN system as a whole? We find that the warm absorbers of nearby Seyferts and certain QSOs are most likely to originate in outflows from the dusty torus, and that the kinetic luminosity of these outflows accounts for well under 1% of the bolometric luminosities of the AGN. Our analysis supports, however, the view that the relativistic outflows recently observed in two PG quasars have their origin in accretion disc winds, although the energetic importance of these outflows is similar to that of the Seyfert warm absorbers. We find that the observed soft X-ray absorbing ionisation phases fill less than 10% of the available volume. Finally, we show that the amount of matter processed through an AGN outflow system, over the lifetime of the AGN, is probably large enough to have a significant influence on the evolution of the host galaxy and of the AGN itself.Comment: v2: 15 pages, 9 figures, accepted for publication in A&A, minor typos correcte

Fatty-acid amide hydrolase polymorphisms and post-traumatic stress disorder after penetrating brain injury

The past few years have seen an increase in the clinical awareness of post-traumatic stress disorder (PTSD), one of the most disabling and least understood behavioral disorders. Although the biological bases of PTSD are poorly understood, fatty-acid amide hydrolase (FAAH) activity has been linked with arousability and aversive-memories extinction, that is, two key features of PTSD. In this study, we investigated the association between the FAAH genetic polymorphisms and PTSD development and maintenance. We assessed PTSD frequency in a group of male Vietnam war veterans who suffered combat-related penetrating traumatic brain injury, that is, a relatively homogeneous population regarding the nature of the events that led to PTSD. We showed that rs2295633, a single-nucleotide polymorphism of FAAH, was significantly associated with PTSD diagnosis in subjects without lesions in the ventromedial prefrontal cortex. Moreover, the presence of the C allele was associated with more severe re-experiencing of trauma and more negative reported childhood experiences. In conclusion, our data suggest that FAAH has an important role in PTSD through modulation of aversive memories and point to both a novel therapeutic target and a possible risk marker for this condition

General Relativistic Radiative Transfer: Applications to Black-Hole Systems

We present general relativistic radiation transfer formulations which include opacity effects due to absorption, emission and scattering explicitly. We consider a moment expansions for the transfer in the presence of scattering. The formulation is applied to calculation emissions from accretion and outflows in black-hole systems. Cases with thin accretion disks and accretion tori are considered. Effects, such as emission anisotropy, non-stationary flows and geometrical self-occultation are investigated. Polarisation transfer in curved space-time is discussed qualitatively