Description of the 40 video clips showing dog behaviour and the corresponding possible interpretation(s).

The twenty video clips that received the most extreme scores on the difficulty ratings after scanning are marked with a cross in the column ‘easy’ (10 clips with the lowest scores) or ‘difficult’ (10 clips with the highest scores). In the fMRI analyses, brain activation during the observation of these ten difficult video clips is compared with brain activation during the observation of these ten easy video clips. Some video clips showed the same behaviour. For example, there are two video clips that showed a dog drinking water. When this is the case the number of video clips showing this behaviour is reported between brackets.