2.1 Participants
The sample size was based on previous ERP-based fCIT
research in which large and moderate-to-large effects were found for the
interaction effect between the stimulus and group (effect sizes ranging
from ηp2 = 0.18 to 0.59; Sai et al. 2016, 2020). For our power analysis, using G*Power 3.1 (Faul,
Erdfelder, Buchner, & Lang, 2009) and selecting “ANOVA: Repeated
measures, within-between interaction”, a moderate effect size of
f = 0.25, an alpha rejection criterion of 0.05, power of 0.95, two
groups and four measurements, a correlation of 0.5 and a nonsphericity
correction of 1, we required a minimum sample of 36 participants for the
current research design. Considering potential dropout (e.g., data
quality), we therefore recruited sixty participants (23 males, mean age
= 20.7 years, SD = 2.2 years) for the fCIT study, and they were paid 60
RMB (approximately 9.18 USD) for their time. All participants had normal
or corrected-to-normal vision, and were right-handed. None had any
history of neurological or psychiatric disorder. No participants were
excluded from the ERP analyses. The study was conducted in accordance
with guidelines approved by the Ethics Committee of Hangzhou Normal
University.