Electrocorticographic dissociation of alpha and beta rhythmic activity in the human sensorimotor system.

This study uses electrocorticography in humans to assess how alpha- and beta-band rhythms modulate excitability of the sensorimotor cortex during psychophysically-controlled movement imagery. Both rhythms displayed effector-specific modulations, tracked spectral markers of action potentials in the local neuronal population, and showed spatially systematic phase relationships (traveling waves). Yet, alpha- and beta-band rhythms differed in their anatomical and functional properties, were weakly correlated, and traveled along opposite directions across the sensorimotor cortex. Increased alpha-band power in the somatosensory cortex ipsilateral to the selected arm was associated with spatially-unspecific inhibition. Decreased beta-band power over contralateral motor cortex was associated with a focal shift from relative inhibition to excitation. These observations indicate the relevance of both inhibition and disinhibition mechanisms for precise spatiotemporal coordination of movement-related neuronal populations, and illustrate how those mechanisms are implemented through the substantially different neurophysiological properties of sensorimotor alpha- and beta-band rhythms.

Do clinicians use more question marks?

OBJECTIVE: To quantify the use of question marks in titles of published studies. DESIGN AND SETTING: Literature review. PARTICIPANTS: All Pubmed publications between 1 January 2013 and 31 December 2013 with an available abstract. Papers were classified as being clinical when the search terms clin*, med* or patient* were found anywhere in the paper's title, abstract or the journal's name. Other papers were considered controls. As a verification, clinical journals were compared to non-clinical journals in two different approaches. Also, 50 highest impact journals were explored for publisher group dependent differences. MAIN OUTCOME MEASURE: Total number of question marks in titles. RESULTS: A total of 368,362 papers were classified as clinical and 596,889 as controls. Clinical papers had question marks in 3.9% (95% confidence interval 3.8-4.0%) of titles and other papers in 2.3% (confidence interval 2.3-2.3%; p < 0.001). These findings could be verified for clinical journals compared to non-clinical journals. Different percentages between four publisher groups were found (p < 0.01). CONCLUSION: We found more question marks in titles of clinical papers than in other papers. This could suggest that clinicians often have a question-driven approach to research and scientists in more fundamental research a hypothesis-driven approach. An alternative explanation is that clinicians like catchy titles. Publishing groups might have pro- and anti-question mark policies.