Figure 4. Classification of brain responses during immediate expression test.

Supervised machine-learning classification of haemodynamic pattern to the CS+ during the immediate expression test as Naltrexone or Placebo group. Highest values for classification were yielded in anterior temporal regions, including the bilateral anterior temporal gyrus and the left temporal pole, as well as the right caudate and right thalamus (see Supplementary Table 6 for a contribution of all regions). Please note that only regions responsive to the observational US were included in the training kernel. T-maps are superimposed on an average structural image with a threshold of P(uncorrected)<0.01 for illustrative purposes.