  Quiescent galaxies generally possess denser cores than star-forming galaxies
with similar mass. As a measurement of the core density, the central stellar
mass surface density within a radius of 1 kpc ($\Sigma_1$) was thus suggested
to be closely related to galaxy quenching. Massive star-forming galaxies with
high $\Sigma_1$ do not fit into this picture. To understand the origin of such
galaxies, we compare the spatially-resolved stellar population and star
formation properties of massive ($ > 10^{10.5}{\rm M}_{\odot}$) blue spiral
galaxies with high and low $\Sigma_1$, divided by $\Sigma_1 = 10^{9.4} M_\odot
\, {\rm kpc}^{-2}$, based on the final release of MaNGA IFU data. We find that
both high $\Sigma_1$ and low $\Sigma_1$ blue spirals show large diversities in
stellar population and star formation properties. Despite the diversities, high
$\Sigma_1$ blue spirals are statistically different from the low $\Sigma_1$
ones. Specifically, the radial profiles of the luminosity-weighted age and
Mgb/${\rm \langle Fe \rangle}$ show that high $\Sigma_1$ blue spirals consist
of a larger fraction of galaxies with younger and less $\alpha$-element
enhanced centers than their low $\Sigma_1$ counterparts, $\sim 55\%$ versus
$\sim 30\%$. The galaxies with younger centers mostly have higher central
specific star formation rates, which still follow the spaxel-based star
formation main sequence relation though. Examinations of the H$\alpha$ velocity
field and the optical structures suggest that galactic bars or galaxy
interactions should be responsible for the rejuvenation of these galaxies. The
remaining $\sim 45\% $ of high $\Sigma_1$ blue spirals are consistent with the
inside-out growth scenario.
