Cortex; a journal devoted to the study of the nervous system and behavior
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Traumatic brain injury (TBI) is associated with neuronal loss, diffuse axonal injury and executive dysfunction. Whereas executive dysfunction has traditionally been associated with prefrontal lesions, ample evidence suggests that those functions requiring behavioral flexibility critically depend on the interaction between frontal cortex, basal ganglia and thalamus. To test whether structural integrity of this fronto-striato-thalamic circuit can account for executive impairments in TBI we automatically segmented the thalamus, putamen and caudate of 25 patients and 21 healthy controls and obtained diffusion weighted images. ⋯ Global volume of the nuclei showed no clear relationship with task performance. However, the shape analysis revealed that participants with smaller volume of those subregions that have connections with the prefrontal cortex and rostral motor areas showed higher switch costs and mixing costs, and made more errors while switching. These results support the idea that flexible cognitive control over action depends on interactions within the fronto-striato-thalamic circuit.
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Creativity is imperative to the progression of civilization and is central to cultural life. Many neuroimaging studies have investigated the patterns of functional activity in the brain during different creative tasks, and the structural and functional characteristics of the highly creative individuals. However, few studies have investigated resting-state functional connectivity (RSFC) in the brain related to individual differences in creativity, and it is still unclear whether the RSFC underlying creativity can be changed by training. ⋯ In addition, behavioral data showed that cognitive stimulation was successful in enhancing originality in a subset of the original participants (n = 34). Most interesting, we found that there was also a significantly increased RSFC between the mPFC and the mTG by analyzing the data of Rs-fMRI after creativity training. Taken together, these results suggest that increased RSFC between mPFC and mTG, which belong to the default mode network might be crucial to creativity, and that RSFC between the mPFC and mTG can be improved by means of cognitive stimulation (reflecting creativity training-induced changes in functional connectivity, especially in the lower creativity individuals who had lower scores of Torrance Tests of Creative Thinking).