Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

Thirty years of brain imaging research has converged to define the brain’s default network—a novel and only recently appreciated brain system that participates in internal modes of cognition Here we synthesize past observations to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment Analysis of connectional anatomy in the monkey supports the presence of an interconnected brain system Providing insight into function, the default network is active when individuals are engaged in internally focused tasks including autobiographical memory retrieval, envisioning the future, and conceiving the perspectives of others Probing the functional anatomy of the network in detail reveals that it is best understood as multiple interacting subsystems The medial temporal lobe subsystem provides information from prior experiences in the form of memories and associations that are the building blocks of mental simulation The medial prefrontal subsystem facilitates the flexible use of this information during the construction of self-relevant mental simulations These two subsystems converge on important nodes of integration including the posterior cingulate cortex The implications of these functional and anatomical observations are discussed in relation to possible adaptive roles of the default network for using past experiences to plan for the future, navigate social interactions, and maximize the utility of moments when we are not otherwise engaged by the external world We conclude by discussing the relevance of the default network for understanding mental disorders including autism, schizophrenia, and Alzheimer’s disease

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The Brain's Default Network Anatomy, Function, and Relevance to Disease

During performance of attention-demanding cognitive tasks, certain regions of the brain routinely increase activity, whereas others routinely decrease activity. In this study, we investigate the extent to which this task-related dichotomy is represented intrinsically in the resting human brain through examination of spontaneous fluctuations in the functional MRI blood oxygen level-dependent signal. We identify two diametrically opposed, widely distributed brain networks on the basis of both spontaneous correlations within each network and anticorrelations between networks. One network consists of regions routinely exhibiting task-related activations and the other of regions routinely exhibiting task-related deactivations. This intrinsic organization, featuring the presence of anticorrelated networks in the absence of overt task performance, provides a critical context in which to understand brain function. We suggest that both task-driven neuronal responses and behavior are reflections of this dynamic, ongoing, functional organization of the brain.

https://www.pnas.org/content/pnas/102/27/9673.full.pdf

The human brain is intrinsically organized into dynamic, anticorrelated functional networks

Research on moral judgment has been dominated by rationalist models, in which moral judgment is thought to be caused by moral reasoning. The author gives 4 reasons for considering the hypothesis that moral reasoning does not cause moral judgment; rather, moral reasoning is usually a post hoc construction, generated after a judgment has been reached. The social intuitionist model is presented as an alternative to rationalist models. The model is a social model in that it deemphasizes the private reasoning done by individuals and emphasizes instead the importance of social and cultural influences. The model is an intuitionist model in that it states that moral judgment is generally the result of quick, automatic evaluations (intuitions). The model is more consistent than rationalist models with recent findings in social, cultural, evolutionary, and biological psychology, as well as in anthropology and primatology.

https://www.motherjones.com/files/emotional_dog_and_rational_tail.pdf

The emotional dog and its rational tail: a social intuitionist approach to moral judgment.

This article describes a 2-systems model that explains social behavior as a joint function of reflective and impulsive processes. In particular, it is assumed that social behavior is controlled by 2 interacting systems that follow different operating principles. The reflective system generates behavioral decisions that are based on knowledge about facts and values, whereas the impulsive system elicits behavior through associative links and motivational orientations. The proposed model describes how the 2 systems interact at various stages of processing, and how their outputs may determine behavior in a synergistic or antagonistic fashion. It extends previous models by integrating motivational components that allow more precise predictions of behavior. The implications of this reflective–impulsive model are applied to various phenomena from social psychology and beyond. Extending previous dual-process accounts, this model is not limited to specific domains of mental functioning and attempts to integrate cognitive, motivational, and behavioral mechanisms.

/pdf/reflective-and-impulsive-determinants-of-social-behavior-fd62htt3ys.pdf

Reflective and Impulsive Determinants of Social Behavior

The long-standing rationalist tradition in moral psychology emphasizes the role of reason in moral judgment. A more recent trend places increased emphasis on emotion. Although both reason and emotion are likely to play important roles in moral judgment, relatively little is known about their neural correlates, the nature of their interaction, and the factors that modulate their respective behavioral influences in the context of moral judgment. In two functional magnetic resonance imaging (fMRI) studies using moral dilemmas as probes, we apply the methods of cognitive neuroscience to the study of moral judgment. We argue that moral dilemmas vary systematically in the extent to which they engage emotional processing and that these variations in emotional engagement influence moral judgment. These results may shed light on some puzzling patterns in moral judgment observed by contemporary philosophers.

https://science.sciencemag.org/content/sci/293/5537/2105.full.pdf

An fMRI Investigation of Emotional Engagement in Moral Judgment

Objective
To identify the causative gene in an autosomal dominant limb-girdle muscular dystrophy (LGMD) with skeletal muscle vacuoles.

/pdf/exome-sequencing-reveals-dnajb6-mutations-in-dominantly-58iwiifp2w.pdf

Exome sequencing reveals DNAJB6 mutations in dominantly-inherited myopathy.

Introduction: Ipilimumab, a monoclonal anti–CTLA-4 antibody, is used to treat melanoma. Neuromuscular side effects, possibly autoimmune, may occur. Methods: In this investigation we undertook a retrospective review of patient records. Results: After 3 doses of ipilimumab, a 31-year-old man developed asymmetric, severe weakness involving all limbs, respiration, and cranial nerves, which was progressive over 2 weeks. EMG/NCS showed an axonal polyradiculoneuropathy with multifocal motor conduction blocks. CSF protein was 749 mg/dl. Nerve pathology showed inflammation around the endoneurial microvessels and subperineurial edema and inflammation. Spine MRI showed leptomeningeal and anterior and posterior root enhancement. Strength improved slowly over months after ipilimumab discontinuation and immunomodulating treatment. Conclusions: Ipilimumab toxicity presented as a monophasic, multifocal, asymmetric polyradiculoneuropathy involving roots and peripheral and cranial nerves. Ipilimumab may produce a polyradiculoneuropathy with disruption of the blood–nerve barrier due to a microvasculopathy. Muscle Nerve 48: 440–444, 2013

Multifocal radiculoneuropathy during ipilimumab treatment of melanoma

INTRODUCTION CANOMAD/CANDA are syndromes characterized by ataxic neuropathy, ophthalmoplegia, monoclonal gammopathy, cold agglutinins and disialosyl antibodies. METHODS A retrospective review of our neuromuscular autoantibody panel database was performed. Anti-GD1b seropositive patients with ataxia were included. RESULTS Eleven patients were identified. Median age at onset was 56 years. Median disease duration was 6 years. All patients had gait disorders. Nine had ocular motility abnormalities. Most had a monoclonal protein and all had elevated serum IgM. Electrodiagnostic studies showed a mixed axonal/demyelinating pattern (6), an axonal pattern (4), or a pure demyelinating pattern (1). Ultrasounds showed nerve enlargement patterns consistent with acquired demyelination. A nerve biopsy showed near complete loss of myelinated axons with preservation of smaller axons. Rituximab was the most effective immunotherapy. CONCLUSION CANOMAD/CANDA are rare and debilitating disorders with characteristic clinical and diagnostic findings. In our cohort, nerve ultrasound showed regional nerve enlargement and rituximab was the most effective immunomodulatory therapy.

CANOMAD and other chronic ataxic neuropathies with disialosyl antibodies (CANDA)

Introduction:
In this investigation we studied clinical and laboratory features of polyneuropathies in patients with serum IgM binding to the trisulfated disaccharide IdoA2S-GlcNS-6S (TS-HDS).

Methods:
We retrospectively compared 58 patients with selective IgM binding to TS-HDS to 41 consecutive patients with polyneuropathies without TS-HDS binding.

Results:
Patients with IgM vs. TS-HDS commonly had distal, sensory, axonal neuropathies. Weakness was associated with IgM M-proteins. Hand pain and serum IgM M-proteins were more common than in control neuropathy patients. TS-HDS antibody binding was often selectively κ class. Biopsies showed capillary pathology with thickened basal lamina and C5b9 complement deposition. IgM in sera with TS-HDS antibodies often bound to capillaries.

Conclusions:
Serum IgM binding to TS-HDS is associated with painful, sensory > motor, polyneuropathies with an increased frequency of persistent hand discomfort, serum IgM M-proteins, and capillary pathology. Serum IgM binding to TS-HDS suggests a possible immune etiology underlying some otherwise idiopathic sensory polyneuropathies. Muscle Nerve 45: 866–872, 2012

R. Brian Sommerville

Papers

An fMRI Investigation of Emotional Engagement in Moral Judgment

Exome sequencing reveals DNAJB6 mutations in dominantly-inherited myopathy.

Multifocal radiculoneuropathy during ipilimumab treatment of melanoma

CANOMAD and other chronic ataxic neuropathies with disialosyl antibodies (CANDA)

Clinical and laboratory features of neuropathies with serum IgM binding to TS-HDS