Time-compressed speech is an artificial form of rapidly presented speech.
Training with time compressed speech in a second language leads to adaptation toward
time-compressed speech in a second language and toward time compressed speech in
different languages. However, the effects of training with time-compressed speech of a
second language (TCSSL) on diverse cognitive functions and neural mechanisms
beyond time compressed speech-related activation are unknown. We investigated the
effects of 4 weeks of training with TCSSL on the fractional amplitude of spontaneous
low-frequency fluctuations (fALFF) of 0.01–0.08 Hz, resting-state functional
connectivity (RSFC) with the left superior temporal gyrus (STG), fractional anisotropy
(FA), and regional gray matter volume (rGMV) of young adults by magnetic resonance
imaging. There were no significant differences in change of performance of measures of
cognitive functions or second language skills after training with TCSSL compared with
that of the active control group. However, compared with the active control group,
training with TCSSL was associated with increased fALFF, RSFC, and FA and
decreased rGMV involving areas in the left STG. These results lacked evidence of a far
transfer effect of time compressed speech training on a wide range of cognitive
functions and second language skills in young adults. However, these results
demonstrated effects of time compressed speech training on gray and white matter
structures as well as on resting-state intrinsic activity and connectivity involving the left
STG, which plays a key role in listening comprehension
