The Impact of Mercenaries and Private Military and Security Companies on Civil War Severity between 1946 and 2002

Research has long abandoned the view that only states wage war. On the contrary, civil war research has produced an impressive body of literature on violent non-state actors. Still, a particular group of actors—mercenaries—has been widely neglected so far, although they have participated in numerous conflicts in the second half of the twentieth century. Whether their presence aggravated or improved the situation is a matter of dispute. Some believe that the additional military capabilities provided by mercenaries help to end civil wars quickly without increased bloodshed, while others deem mercenaries greedy and bloodthirsty combatants who contribute to making civil wars more brutal, while a third opinion differentiates between different types of mercenaries. This article tests the impact of mercenaries on civil war severity. The evidence indicates that the presence of both mercenaries and private military and security contractors increases its severity

The Effects of Fluency Enhancing Conditions on Sensorimotor Control of Speech in Typically Fluent Speakers: An EEG Mu Rhythm Study

Objective: To determine whether changes in sensorimotor control resulting from speaking conditions that induce fluency in people who stutter (PWS) can be measured using electroencephalographic (EEG) mu rhythms in neurotypical speakers.Methods: Non-stuttering (NS) adults spoke in one control condition (solo speaking) and four experimental conditions (choral speech, delayed auditory feedback (DAF), prolonged speech and pseudostuttering). Independent component analysis (ICA) was used to identify sensorimotor μ components from EEG recordings. Time-frequency analyses measured μ-alpha (8–13 Hz) and μ-beta (15–25 Hz) event-related synchronization (ERS) and desynchronization (ERD) during each speech condition.Results: 19/24 participants contributed μ components. Relative to the control condition, the choral and DAF conditions elicited increases in μ-alpha ERD in the right hemisphere. In the pseudostuttering condition, increases in μ-beta ERD were observed in the left hemisphere. No differences were present between the prolonged speech and control conditions.Conclusions: Differences observed in the experimental conditions are thought to reflect sensorimotor control changes. Increases in right hemisphere μ-alpha ERD likely reflect increased reliance on auditory information, including auditory feedback, during the choral and DAF conditions. In the left hemisphere, increases in μ-beta ERD during pseudostuttering may have resulted from the different movement characteristics of this task compared with the solo speaking task. Relationships to findings in stuttering are discussed.Significance: Changes in sensorimotor control related feedforward and feedback control in fluency-enhancing speech manipulations can be measured using time-frequency decompositions of EEG μ rhythms in neurotypical speakers. This quiet, non-invasive, and temporally sensitive technique may be applied to learn more about normal sensorimotor control and fluency enhancement in PWS