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Amplitude of low‐frequency fluctuation (ALFF) has been widely used for localization of abnormal activity at the single‐voxel level in resting‐state fMRI (RS‐fMRI) studies. However, previous ALFF studies were based on fast Fourier transform (FFT‐ALFF). Our recent study found that ALFF based on wavelet transform (Wavelet‐ALFF) showed better sensitivity and reproducibility than FFT‐ALFF. The current study aimed to test the reliability and validity of Wavelet‐ALFF, and apply Wavelet‐ALFF to investigate the modulation effect of repetitive transcranial magnetic stimulation (rTMS). The reliability and validity were assessed on multicenter RS‐fMRI datasets under eyes closed (EC) and eyes open (EO) conditions (248 healthy participants in total). We then detected the sensitivity of Wavelet‐ALFF using a rTMS modulation dataset (24 healthy participants). For each dataset, Wavelet‐ALFF based on five mother wavelets (i.e., db2, bior4.4, morl, meyr and sym3) and FFT‐ALFF were calculated in the conventional band and five frequency sub‐bands. The results showed that the reliability of both inter‐scanner and intra‐scanner was higher with Wavelet‐ALFF than with FFT‐ALFF across multiple frequency bands, especially db2‐ALFF in the higher frequency band slow‐2 (0.1992–0.25 Hz). In terms of validity, the multicenter ECEO datasets showed that the effect sizes of Wavelet‐ALFF with all mother wavelets (especially for db2‐ALFF) were larger than those of FFT‐ALFF across multiple frequency bands. Furthermore, Wavelet‐ALFF detected a larger modulation effect than FFT‐ALFF. Collectively, Wavelet db2‐ALFF showed the best reliability and validity, suggesting that db2‐ALFF may offer a powerful metric for inspecting regional spontaneous brain activities in future studies. [ABSTRACT FROM AUTHOR]

Repetitive transcranial magnetic stimulation (rTMS) has been used in the clinical treatment of Parkinson's disease (PD). Most of rTMS studies on PD used high‐frequency stimulation; however, excessive nonvoluntary movement may represent abnormally cortical excitability, which is likely to be suppressed by low‐frequency rTMS. Decreased neural activity in the basal ganglia on functional magnetic resonance imaging (fMRI) is a characteristic of PD. In the present study, we found that low‐frequency (1 Hz) rTMS targeting individual finger‐tapping activation elevated the amplitude of local neural activity (percentage amplitude fluctuation, PerAF) in the putamen as well as the functional connectivity (FC) of the stimulation target and basal ganglia in healthy participants. These results provide evidence for our hypothesis that low‐frequency rTMS over the individual task activation site can modulate deep brain functions, and that FC might serve as a bridge transmitting the impact of rTMS to the deep brain regions. It suggested that a precisely localized individual task activation site can act as a target for low‐frequency rTMS when it is used as a therapeutic tool for PD. [ABSTRACT FROM AUTHOR]