between brain areas during the performance of a task (Posner et al., 

 2006). Two recent studies illustrate the use of fMRI to trace the 

 interaction of the anterior cingulate with other brain areas. In one 

 study subjects were required to switch between auditory and visual 

 modalities (Crottaz-Herbette and Mennon, 2006). The dorsal ante- 

 rior cingulate was coupled either to visual or auditory sensory areas 

 depending on the selected modality. Another study (Etkin et al., 

 2006) required subjects to resolve conflict related to negative emo- 

 tion. The ventral anterior cingulate was shown to be coupled to the 

 amygdala in this form of conflict resolution. Studies requiring peo- 

 ple to control their positive (Beauregard et al., 2001) or negative 

 emotional reaction (Ochsner et al., 2001) to stimuli have shown 

 strong activation in the anterior cingulate compared to studies where 

 subjects viewed the stimuli without the instruction for self-regula- 

 tion. 



INDIVIDUALITY 



The finding that common brain networks are involved in self- 

 regulation provides one important approach to human evolution by 

 looking at commonalities and differences with nonhuman organ- 

 isms. However, another approach of equal importance involves an 

 examination of differences in the efficiency of this network among 

 individuals. Such differences could rest in part upon genetic varia- 

 tion known to exist among individuals and in part upon differences 

 in cultural or individual experience between people. The study of 

 temperament examines individual differences in reactivity and self- 

 regulation that are biologically based (Rothbart and Bates, 2006). 



Effortful Control 



One of the most important of the individual differences has been 

 called "effortful control." It is a higher-order factor consisting of a 

 number of subscales. In children it involves subscales of attention, 

 focus shifting, and inhibitory control. For example, caregivers an- 

 swer questions such as: "when playing alone, how often is your 

 child distracted, how often does your child look immediately when 

 you point?" or adults may be asked "how often do you make plans 

 you do not follow through?" The answers are aggregated for various 



