4.4.2. Language functions Language production has also been under investigation. Two studies used a verbal fluency task with 2 levels of difficulty. Allinet al. (2010), with almost the same population cited in Surguladze’sstudy, found that UR had a similar behavioral pattern than HC. Theyshowed that, in comparison to control subjects, increased retrosplenial/posterior cingulate cortex activation was observed in bothBDP and their UR during the easy and demanding conditions. How-ever, in the easy condition, UR also showed increased precuneusactivation and a decreased left fronto-temporal cortex activation,whereas BDP only showed decreased left frontal cortex activation.In the hard condition, only UR displayed decreased activation in the mPFC. Consequently, when BDP and their UR were comparedto each other, UR had lower vlPFC activation (easy condition) and mPFC activation (hard condition). Costafreda et al., on the otherside, included a large number of bipolar or schizophrenia patients,as well as their monozygotic twins (Costafreda et al., 2009) butchose to look only into Brodmann area (BA) 44 or 45 (inferior frontalcortex) and found that both BDP and their UR showed no significant difference compared to HC, whereas schizophrenia patients and their monozygotic twins did.