Fig. 1.

In our previous study (Frühholz et al., 2012), participants were asked to perform two different tasks. 1) The ‘emotional task’: participants were presented with (emotional or neutral) pseudo-words in which they were asked to explicitly focus their attention on the emotional prosody of the stimuli and to categorize the emotional valence of the voices (forced-choice decision if the voice was ‘neutral’ or ‘angry’). 2) The ‘gender task’: participants were asked to categorize the gender of the voices (forced-choice decision if the voice was ‘male’ or ‘female’). During attention to the gender of the voices as a nonemotional stimulus feature, the emotional (angry) prosody was assumed to be non-task-relevant. In our previous study (Frühholz et al., 2012), left STN activity was specifically reported when participants had to perform the task related to nonemotional features of the voice (i.e. when the focus was on the speaker’s sex) instead of performing a task related to emotional vocal features (i.e. discriminating anger/neutral). In other words, these results indicate that the STN is specifically activated during the processing of non-task-relevant emotional information when attention has to be focused elsewhere (i.e. on gender information). In this study, we performed DTI and PPI analysis on functional imaging data (Friston et al., 1997), taking the left STN as the seed region, in order to explore the structural and functional connectivity between the STN and other brain regions related to vocal emotion in a healthy population.