Browsing by Author "Makkonen, Emilia"

Transcranial direct current stimulation (tDCS) is a method that in recent years has gained the attention of researchers. In certain contexts, tDCS can be utilised in modulating brain function and cognitive performance, and it has been found to modulate symptoms and neural correlates of some pathologies. Due to differences in protocols between studies, the literature is inconclusive on the effects of tDCS on some brain areas and networks. In this study the effects of tDCS directed to medial prefrontal cortex (mPFC) on functional networks of the brain in resting state are examined. 36 healthy female subjects were divided into control and tDCS-groups of equal sizes. Functional networks were examined using functional magnetic resonance imaging (fMRI) in resting state before one stimulation session of 20 minutes with 2 mA current or sham stimulation, and after the session. Functional networks were identified with independent component analysis (ICA), which was performed on the set of images with both groups combined. The groups were then compared on a network level. The tDCS group showed increased functional connectivity in and around the left anterior cingulate cortex (ACC) in language network compared to the sham group. Other networks identified by ICA that showed no statistically significant differences between groups were posterior and anterior default mode, dorsal attention, sensorimotor, orbitofrontal, left and right frontoparietal, medial and lateral visual network, basal ganglia and the cerebellum. The results of this study were partially in line with previous studies that have found increases in the functional connectivity of brain regions associated with reward processing. There is a need for systematic examination of the effects of different tDCS protocols on functional networks in future studies.