Figure 1
From: Gamma tACS over the temporal lobe increases the occurrence of Eureka! moments
Experimental design. (a) A graphical representation of the theoretical model of insight problem-solving proposed by Jung-Beeman and colleagues8, showing the contribution of brain oscillations in the α and γ bands before a Eureka! moment, with α activity in the right parietal lobe (orange circle) preceding a burst of γ band in the right temporal pole (green circle). (b) The role of α oscillations at an early stage, and γ ones right before the successful solution of a given problem, constituted the rationale for the adopted brain stimulation solutions. The detailed modeling of the electrode montage and induced electric field are provided in Fig. S1 and Supplementary Information. (c) Given prior EEG and fMRI evidence, electrical stimulation was delivered over the right parietal and temporal lobes, respectively at 10 Hz and 40 Hz (continuously for each block of stimulation), while participants solved a verbal (CRA) and a visuo-spatial (Rebus Puzzles) insight task. (d) EEG data were recorded before and after each stimulation block (i.e. Sham, 10 Hz tACS on right parietal lobe, 40 Hz on right temporal area). Cognitive and resting-state fMRI data were also collected on a separate day to investigate possible sources of variability in the individual response to tACS (see Supplementary Information).
