xcX3v84RxoQ-4GxG32940ukFUIEgYdPy Fig. 1. Mid-saggital section of the brain showing the corpus callosum. source: University of Central FloridaI think it is not the caudate nucleus, alhough it has also the curved shape. The caudate is positioned more laterally than the corpus callosum and by the looks of it your picture shows a mid-sagittal section of the brain. The caudate seems to be positioned too far laterally in the brain as far as I can see (Fig. 2