Article

The neural substrates of auditory motion processing are, at present, still a
matter of debate. It has been hypothesized that motion information is, as in the
visual system, processed separately from other aspects of auditory information,
such as stationary location. Here we aimed to differentiate the location of
auditory motion processing in human cortex using low-frequency repetitive
transcranial magnetic stimulation (rTMS) in combination with a psychophysical
task of motion discrimination. rTMS was applied offline to right posterior
superior temporal gyrus, right inferior parietal lobule, right dorsal premotor
cortex, or right primary somatosensory cortex (as reference site). A significant
decrease in performance was obtained exclusively for sounds presented in left
hemispace after rTMS over the right inferior parietal lobule (BA 40). This
finding indicates that the inferior parietal lobule plays a crucial role in the
analysis of moving sound, with an apparent contralaterality of cortical
processing. Combined with previous studies which have demonstrated effects of
rTMS on static sound localization for both inferior parietal and posterior
temporal cortices, the results suggest a hierarchical processing of auditory
spatial information, with higher-order functions of motion analysis, such as
discrimination of motion direction, mainly taking place beyond the temporal lobe.
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Langue : ANGLAIS