  Complex permittivity studies on glassy poly(vinyl alcohol)/poly(vinyl
pyrrolidone) (1/1) at proper pressure-temperature condition, provide the
activation volume and energy values for both dc conductivity and
\b{eta}-relaxation. The temperature dependence of the activation volume, which
signatures volume-fluctuations accompanying a dynamic process, maximizes at
temperature near the glass transition temperature of neat polyvinyl alcohol.
The phenomenon is interpreted by a local softening of polyvinyl alcohol
domains, while the blend remains in its glassy state. The scenario is also
supported by the dependence of the activation energy upon pressure. Dispersed
nano-graphene platelets at volume fractions around the critical conductivity
percolation threshold are comparatively studied, so as to determine whether
local softening affects the formation of a conductivity percolation network.
