Mosso was studying the physiological concomitants of various mental states; in particular, he had started recording changes in blood circulation during laboratory-generated emotions. One of his patients, Michele Bertino, was a 37-year-old man who experienced a traumatic injury and was left with only a thin layer of skin covering a gap in his skull. While assessing Bertino with a special sphygmograph (a registering apparatus measuring in vivo brain volume changes, which were interpreted as measurements of brain circulation; see figure), Mosso noticed a sudden increase in pulsations over the cortex when the church bells rang at noon. He then asked Bertino if he felt that he should have said his midday prayers, and when Bertino answered in the positive, the pulsations increased again. Intrigued by that, almost performing a cognitive activation task ante litteram, Mosso asked him to multiply 8 by 12. Once again the sphygmograph recorded an increase in the pulsations, both when the question was asked and when Bertino replied, “96.” From this observation Mosso concluded that changes in circulation of the brain were related to mental activity.