Objective To systematically assess the age differences and parallel form reliabilityin of brain network metrics in naturalistic stimuli functional magnetic resonance imaging (fMRI).

Methods In the present study, the movies Sherlock and The Red Balloon were used as naturalistic stimuli materials. The fMRI data were collected from 46 healthy young adults (28.9 ± 5.23 years) and 32 healthy older adults (59.5 ± 6.33 years), and the functional connectivity and graph theory metrics were computed in order to compare the characteristics of the different age groups andparallel form reliability.

Results The younger group showed stronger functional connectivity and better graph-theoretic features in most brain networks, and the parallel form reliability of these metrics were significantly higher than those of older group.

Conclusions Functional connectivity and graph theory metrics exhibit significant age effects and parallel form reliability differences among different age groups, further supporting the application value of naturalistic stimuli fMRI in the study of functional connectivity of brain networks.