Citation

Diez I, Drijkoningen D, Stramaglia S, Bonifazi P, Marinazzo D, Gooijers J, Swinnen SP, Cortes JM. Netw. Neurosci. 2017; 1(2): 116-142.

Copyright

(Copyright © 2017, MIT Press)

DOI

10.1162/NETN_a_00007

PMID

unavailable

Abstract

Traumatic brain injury (TBI) affects structural connectivity, triggering the reorganization of structural-functional circuits in a manner that remains poorly understood. We focus here on brain network reorganization in relation to postural control deficits after TBI. We enrolled young participants who had suffered moderate to severe TBI, comparing them to young, typically developing control participants. TBI patients (but not controls) recruited prefrontal regions to interact with two separated networks: (1) a subcortical network, including parts of the motor network, basal ganglia, cerebellum, hippocampus, amygdala, posterior cingulate gyrus, and precuneus; and (2) a task-positive network, involving regions of the dorsal attention system, together with dorsolateral and ventrolateral prefrontal regions. We also found that the increased prefrontal connectivity in TBI patients was correlated with some postural control indices, such as the amount of body sway, whereby patients with worse balance increased their connectivity in frontal regions more strongly. The increased prefrontal connectivity found in TBI patients may provide the structural scaffolding for stronger cognitive control of certain behavioral functions, consistent with the observations that various motor tasks are performed less automatically following TBI and that more cognitive control is associated with such actions.

The number of radical Islamist groups fighting in civil wars in Muslim countries has steadily grown over the last twenty years, with such groups outlasting and outperforming more moderate groups. By 2016, Salafi jihadist groups accounted for most of the militant groups in Syria and half of such groups in Somalia. In Iraq, a third of all militant groups were composed of Salafi jihadists. Many analysts argue that the rise of these groups reflects an increase in radical beliefs in Muslim societies. Under certain conditions, however, rebel leaders have strong incentives to embrace an extreme ideology even if they do not believe the ideas that underlie it. When competition is high, information is poor, and institutional constraints are weak, an extremist ideology can help rebel leaders overcome difficult collective-action, principal-agent, and commitment problems. All three of these conditions have been present in the post-2003 civil wars in the Middle East and Africa, and all help explain the emergence and growth of radical groups such as the Islamic State and al-Qaida.


© 2018 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology.

Language: en