Brain activity sensitive to visual congruency effects relates to divergent thinking.

The present study used functional magnetic resonance imagining (fMRI) to examine the role of focused attention in divergent thinking and real-life creativity. Participants completed a Navon task, on which the stimuli consisted of a large letter made up of the smaller version of the same (congruent), or a different (incongruent) letter. Participants were cued to identify a letter at either the local or at the global level. A smaller congruency effect - how much faster people responded on the congruent than on the incongruent trials - was an index of focused attention. Overall, larger behavioral congruency effect was accompanied with increased activation in the anterior superior temporal gyrus (aSTG), and with increased activation in the left precuneus. Individual differences in divergent thinking, however, were associated with smaller behavioral congruency effect, as well as with smaller right aSTG increase on the incongruent versus congruent targets, suggesting that people with better performance on the divergent thinking tests have more focused attention. Real-world creativity was not associated with the congruency effect, or with any of the regions implicated in the congruency effect. Implications and directions for future research are discussed.

Intrahemispheric Perfusion in Chronic Stroke-Induced Aphasia.

Stroke-induced alterations in cerebral blood flow (perfusion) may contribute to functional language impairments and recovery in chronic aphasia. Using MRI, we examined perfusion in the right and left hemispheres of 35 aphasic and 16 healthy control participants. Across 76 regions (38 per hemisphere), no significant between-subjects differences were found in the left, whereas blood flow in the right was increased in the aphasic compared to the control participants. Region-of-interest (ROI) analyses showed a varied pattern of hypo- and hyperperfused regions across hemispheres in the aphasic participants; however, there were no significant correlations between perfusion values and language abilities in these regions. These patterns may reflect autoregulatory changes in blood flow following stroke and/or increases in general cognitive effort, rather than maladaptive language processing. We also examined blood flow in perilesional tissue, finding the greatest hypoperfusion close to the lesion (within 0-6 mm), with greater hypoperfusion in this region compared to more distal regions. In addition, hypoperfusion in this region was significantly correlated with language impairment. These findings underscore the need to consider cerebral perfusion as a factor contributing to language deficits in chronic aphasia as well as recovery of language function.

Hemispheric alpha asymmetry and self-rated originality of ideas.

The generation of highly original ideas in divergent thinking tasks has been found to be associated with task-related changes in the alpha band. The goal of the current study was to determine if exposure to brainwave entrainment (BWE) at the alpha centre frequency before and during performance of a divergent thinking task would result in increases in task-related, event-related synchrony and the production of more highly original ideas. We found that alpha entrainment interfered with the oscillatory dynamics associated with divergent thinking such that only the control group showed greater right hemispheric engagement. Furthermore, the control group showed greater self-rated originality. These findings provide confirmation of the importance of hemispheric asymmetry in alpha power to successful divergent thinking and indicate that refinements are required in order for BWE to be used effectively to improve divergent thinking performance.