Atention Deficit Disorder,
The lack of dopamin at the ACC as the cause of ADD
It is thought that the dorsal ACC is primarly involved in cognitive processing[1]. 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[2]. Rats with lisions in the ACC, prefer less effortful mission with less reward, to tasks with more effortful with more reward[3].The ACC motivation mechanism is dependent on dopamin[4][5]. 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.
Mechanism of ADD
Temporal joins of objects probably happen in the working memory (For description on the neural mechanism of Working memory see this reference [6]). It seems that the joins are usually done base on the synaptic strength. Therefore the most rehearsed networks will be more available (This seems to be the mechanism of system 1). In case of ADD it seems that the the brain will have hard time to maintain a flow. It seems also that there is some mechanism that help the brain focus on specific objects. This is neede to be able to think about specific issues.
References
- ↑ Bush G, Luu P & Posner MI, Cognotve and emotional influances in the anterior cingulate cotrex, Trends. Cogn. Sci. 4, 215-222 (2000)
- ↑ Struss DT et al.,2005, Multiple frontal systems controlling response speed, Neuropshichologia, 43: 396-417
- ↑ Walton ME at al, 2003, Fanctional specilization within medial frontal cortex of the antirior cingulate for evaluating effort-related decisions, J Neurosci, 23: 6475-6479
- ↑ Assadi SM, Yucel M & Pantelis C, 2009, Dopamin Modulates neural netowrks involved in effort-based decision making, Neurosci Biobehav, 33: 383-393
- ↑ Alexander MP, 2001, Chronic akinetic mutism after mesanphilic-diancphelick infraction: remediated with dopaminergic medications, Neurohabil Nural Repai, 15:151-156
- ↑ Constantinidis, Christos, and Torkel Klingberg. "The neuroscience of working memory capacity and training." Nature Reviews Neuroscience (2016).