Study design
handedness
The current study was part of a more extensive investigation of the effect of different stimulation training paradigms on arithmetic learning. The current study mainly investigates the functional and structural changes induced by stimulation. The study adopted a between-subjects, double-blinded, placebo-controlled, randomized parallel group design, was in line with the Helsinki declaration on ethical standards and approved by the local ethics committee at the University of Graz. Before any assessments started, the participants were informed about the study goals, and they read the study description. Then they were screened for inclusion and exclusion criteria, and if they were eligible, they were asked to sign a consent to enroll in the study. They were pseudo-randomly assigned to one of the two groups, i.e., experimental and sham. The experiment had a total duration of 5 days. On day one, we collected baseline behavioral and fMRI data. At the start, participants filled out a demographic questionnaire, a questionnaire ascertaining their handedness (Nicholls et al. The design of the study. Participants engaged in a 5-day experiment. On day 1, baseline assessments, including demographic, handedness, and mood (MDBF) questionnaires, were filled in. The participant performed computerized working memory (WM; N-Back task) and proactive interference (recent probes task, RPT) tasks. MRI scans were collected after questionnaires and behavioral measures. Alpha peak was assessed from Day 2 to Day 4, and individualized stimulation was administered, during which participants engaged in arithmetic training tasks. On day 5, MRI scanning, arithmetic tasks, N-back task, and proactive interference tasks similar to baseline measures were carried out