It is thought that the dorsal ACC is primarly involved in cognitive processing<ref>Bush G, Luu P & Posner MI, Cognotve and emotional influances in the anterior cingulate cotrex, Trends. Cogn. Sci. 4, 215-222 (2000)</ref>. It is part of the learning mechanism, that learn the positive and negative outcomes of actions. It is also a reward mechanism, that gives "globals enrgizing factor", to actions that in the past seems to be rewarding<ref>Struss DT et al.,2005, Multiple frontal systems controlling response speed, ''Neuropshichologia'', 43: 396-417</ref>. Rats with lisions in the ACC, prefer less effortful mission with less reward, to tasks with more effortful with more reward<ref>54Walton ME at al, 2003, Fanctional specilization within medial frontal cortex of the antirior cingulate for evaluating effort-related decisions, ''J Neurosci'', 23: 6475-6479</ref>.The ACC motivation mechanism is dependent on dopamin<ref>Assadi SM, Yucel M & Pantelis C, 2009, Dopamin Modulates neural netowrks involved in effort-based decision making, ''Neurosci Biobehav'', 33: 383-393</ref><ref>Alexander MP, 2001, Chronic akinetic mutism after mesanphilic-diancphelick infraction: remediated with dopaminergic medications, ''Neurohabil Nural Repai'', 15:151-156</ref>. The Meutation in Dopamin receptor D2 may lower the amount of dopamin recived by the ACC, thus it may be the cause that make people with Atention Deficit Disorder ([[ADD]]), have lack of motivation to engage in effortful actions and decision making.