Editing Anterior cingulate cortex (section)

==Functions==
Many studies attribute specific functions such as [[error detection]], anticipation of tasks, [[attention]],<ref name="Pardo90" /><ref>{{cite journal | vauthors = Weissman DH, Gopalakrishnan A, Hazlett CJ, Woldorff MG | title = Dorsal anterior cingulate cortex resolves conflict from distracting stimuli by boosting attention toward relevant events | journal = Cerebral Cortex | volume = 15 | issue = 2 | pages = 229–37 | date = February 2005 | pmid = 15238434 | doi = 10.1093/cercor/bhh125 | doi-access = free }}</ref> [[motivation]], and modulation of emotional responses to the ACC.<ref name=Bush00/><ref name=Posner98/><ref name="Nieuw01">{{cite journal | vauthors = Nieuwenhuis S, Ridderinkhof KR, Blom J, Band GP, Kok A | title = Error-related brain potentials are differentially related to awareness of response errors: evidence from an antisaccade task | journal = Psychophysiology | volume = 38 | issue = 5 | pages = 752–60 | date = September 2001 | pmid = 11577898 | doi = 10.1111/1469-8986.3850752 | s2cid = 7566915 }}</ref>

===Error detection and conflict monitoring===
The most basic form of ACC theory states that the ACC is involved with [[error detection]].<ref name=Bush00/> Evidence has been derived from studies involving a [[Stroop task]].<ref name=Posner98/> However, ACC is also active during correct response, and this has been shown using a letter task, whereby participants had to respond to the letter X after an A was presented and ignore all other letter combinations with some letters more competitive than others.<ref>{{cite journal | vauthors = Carter CS, Braver TS, Barch DM, Botvinick MM, Noll D, Cohen JD | title = Anterior cingulate cortex, error detection, and the online monitoring of performance | journal = Science | volume = 280 | issue = 5364 | pages = 747–9 | date = May 1998 | pmid = 9563953 | doi = 10.1126/science.280.5364.747 | bibcode = 1998Sci...280..747C | s2cid = 264267292 }}</ref> They found that for more competitive stimuli ACC activation was greater.

A similar theory poses that the ACC's primary function is the monitoring of conflict. In [[Eriksen flanker task]], incompatible trials produce the most conflict and the most activation by the ACC. Upon detection of a conflict, the ACC then provides cues to other areas in the brain to cope with the conflicting control systems.

==== Evidence from electrical studies ====
Evidence for ACC as having an error detection function comes from observations of [[error-related negativity]] (ERN) uniquely generated within the ACC upon error occurrences.<ref name=Bush00/><ref>{{cite journal |vauthors=Gehring WJ, Goss B, Coles MG, Meyer DE, Donchin E |title=A neural system for error-detection and compensation |journal=Psychological Science |volume=4 |issue=6 |pages=385–90 |date=November 1993 |doi=10.1111/j.1467-9280.1993.tb00586.x  |s2cid=17422146 }}</ref><ref name="Holroyd04">{{cite book |vauthors=Holroyd CB, Nieuwenhuis S, Mars RB, Coles MG |chapter=Anterior cingulate cortex, selection for action, and error processing |editor=Posner MI |title=Cognitive neuroscience of attention |publisher=Guilford Press |location=New York |year=2004 |pages=[https://archive.org/details/cognitiveneurosc0000unse_q4e4/page/219 219–31] |isbn=1-59385-048-4 |chapter-url=https://archive.org/details/cognitiveneurosc0000unse_q4e4/page/219 }}</ref><ref name="Luu04">{{cite book |vauthors=Luu P, Pederson SM |chapter=The anterior cingulate cortex: Regulating actions in context |editor=Posner MI |title=Cognitive neuroscience of attention |publisher=Guilford Press |location=New York |year=2004 |isbn=1-59385-048-4 |url-access=registration |url=https://archive.org/details/cognitiveneurosc0000unse_q4e4 }}</ref> A distinction has been made between an [[Event-related potential|ERP]] following incorrect responses (response ERN) and a signal after subjects receive feedback after erroneous responses (feedback ERN).

Patients with lateral prefrontal cingulate (PFC) damage show reduced ERNs.<ref>{{cite journal | vauthors = Gehring WJ, Knight RT | title = Prefrontal-cingulate interactions in action monitoring | journal = Nature Neuroscience | volume = 3 | issue = 5 | pages = 516–20 | date = May 2000 | pmid = 10769394 | doi = 10.1038/74899 | s2cid = 11136447 }}</ref>

Reinforcement learning ERN theory poses that there is a mismatch between actual response execution and appropriate response execution, which results in an ERN discharge.<ref name=Bush00/><ref name=Holroyd04/> Furthermore, this theory predicts that, when the ACC receives conflicting input from control areas in the brain, it determines and allocates which area should be given control over the motor system. Varying levels of dopamine are believed to influence the optimization of this filter system by providing expectations about the outcomes of an event. The ERN, then, serves as a beacon to highlight the violation of an expectation.<ref name=Luu04/> Research on the occurrence of the feedback ERN shows evidence that this potential has larger amplitudes when violations of expectancy are large. In other words, if an event is not likely to happen, the feedback ERN will be larger if no error is detected. Other studies have examined whether the ERN is elicited by varying the cost of an error and the evaluation of a response.<ref name=Holroyd04/>

In these trials, feedback is given about whether the participant has gained or lost money after a response. Amplitudes of ERN responses with small gains and small losses were similar. No ERN was elicited for any losses as opposed to an ERN for no wins, even though both outcomes are the same. The finding in this paradigm suggests that monitoring for wins and losses is based on the relative expected gains and losses. If you get a different outcome than expected, the ERN will be larger than for expected outcomes. ERN studies have also localized specific functions of the ACC.<ref name=Luu04/>

The rostral ACC seems to be active after an error commission, indicating an error response function, whereas the dorsal ACC is active after both an error and feedback, suggesting a more evaluative function (for fMRI evidence, see also<ref name="Bush02">{{cite journal | vauthors = Bush G, Vogt BA, Holmes J, Dale AM, Greve D, Jenike MA, Rosen BR | title = Dorsal anterior cingulate cortex: a role in reward-based decision making | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 99 | issue = 1 | pages = 523–8 | date = January 2002 | pmid = 11756669 | pmc = 117593 | doi = 10.1073/pnas.012470999 | bibcode = 2002PNAS...99..523B | doi-access = free }}</ref><ref name="Polli">{{cite journal | vauthors = Polli FE, Barton JJ, Cain MS, Thakkar KN, Rauch SL, Manoach DS | title = Rostral and dorsal anterior cingulate cortex make dissociable contributions during antisaccade error commission | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 102 | issue = 43 | pages = 15700–5 | date = October 2005 | pmid = 16227444 | pmc = 1255733 | doi = 10.1073/pnas.0503657102 | bibcode = 2005PNAS..10215700P | doi-access = free }}</ref><ref name="Taylor06">{{cite journal | vauthors = Taylor SF, Martis B, Fitzgerald KD, Welsh RC, Abelson JL, Liberzon I, Himle JA, Gehring WJ | title = Medial frontal cortex activity and loss-related responses to errors | journal = The Journal of Neuroscience | volume = 26 | issue = 15 | pages = 4063–70 | date = April 2006 | pmid = 16611823 | pmc = 6673891 | doi = 10.1523/JNEUROSCI.4709-05.2006 }}</ref> ). This evaluation is emotional in nature and highlights the amount of distress associated with a certain error.<ref name=Bush00/> Summarizing the evidence found by ERN studies, it appears to be the case that ACC receives information about a stimulus, selects an appropriate response, monitors the action, and adapts behavior if there is a violation of expectancy.<ref name=Luu04/>

=== Social evaluation ===
Activity in the dorsal anterior cingulate cortex (dACC) has been implicated in processing both the detection and appraisal of social processes, including [[social exclusion]]. When exposed to repeated personal social evaluative tasks, non-depressed women showed reduced [[fMRI]] [[Blood-oxygen-level dependent imaging|BOLD]] activation in the dACC on the second exposure, while women with a history of [[Depression (mood)|depression]] exhibited enhanced BOLD activation. This differential activity may reflect enhanced rumination about social evaluation or enhanced arousal associated with repeated social evaluation.<ref>{{cite journal | vauthors = Dedovic K, Slavich GM, Muscatell KA, Irwin MR, Eisenberger NI | title = Dorsal Anterior Cingulate Cortex Responses to Repeated Social Evaluative Feedback in Young Women with and without a History of Depression | journal = Frontiers in Behavioral Neuroscience | volume = 10 | pages = 64 | date = 2016 | pmid = 27065828 | pmc = 4815251 | doi = 10.3389/fnbeh.2016.00064 | doi-access = free }}</ref>

The anterior cingulate cortex gyrus is involved in effort to help others.<ref>{{cite web|url=https://neurosciencenews.com/accg-helping-hand-21297/|title=When Can We Be Bothered to Help Others? Brain Region Responsible for This Behavior Discovered|date=August 26, 2022}}</ref>

===Reward-based learning theory===
A more comprehensive and recent theory describes the ACC as a more active component and poses that it detects and monitors errors, evaluates the degree of the error, and then suggests an appropriate form of action to be implemented by the motor system. Earlier evidence from electrical studies indicate the ACC has an evaluative component, which is indeed confirmed by [[fMRI]] studies.
The dorsal and rostral areas of the ACC both seem to be affected by rewards and losses associated with errors. During one study, participants received monetary rewards and losses for correct and incorrect responses, respectively.<ref name=Bush02/>

Largest activation in the dACC was shown during loss trials. This stimulus did not elicit any errors, and, thus, error detection and monitoring theories cannot fully explain why this ACC activation would occur. The dorsal part of the ACC seems to play a key role in reward-based decision-making and learning. The rostral part of the ACC, on the other hand, is believed to be involved more with affective responses to errors. In an interesting expansion of the previously described experiment, the effects of rewards and costs on ACC's activation during error commission was examined.<ref name=Taylor06/> Participants performed a version of the [[Eriksen flanker task]] using a set of letters assigned to each response button instead of arrows.

Targets were flanked by either a congruent or an incongruent set of letters. Using an image of a thumb (up, down, or neutral), participants received feedback on how much money they gained or lost. The researchers found greater rostral ACC activation when participants lost money during the trials. The participants reported being frustrated when making mistakes. Because the ACC is intricately involved with error detection and affective responses, it may very well be that this area forms the basis of self-confidence. Taken together, these findings indicate that both the dorsal and rostral areas are involved in evaluating the extent of the error and optimizing subsequent responses. A study confirming this notion explored the functions of both the dorsal and rostral areas of the ACC involved using a saccade task.<ref name=Polli/>

Participants were shown a cue that indicated whether they had to make either a pro-saccade or an anti-saccade. An anti-saccade requires suppression of a distracting cue because the target appears in the opposite location causing the conflict. Results showed differing activation for the rostral and dorsal ACC areas. Early correct anti-saccade performance was associated with rostral activation. The dorsal area, on the other hand, was activated when errors were committed, but also for correct responses.

Whenever the dorsal area was active, fewer errors were committed providing more evidence that the ACC is involved with [[Effortfulness|effortful]] performance. The second finding showed that, during error trials, the ACC activated later than for correct responses, clearly indicating a kind of evaluative function.

===Role in consciousness===
The ACC area in the brain is associated with many functions that are correlated with conscious experience. Greater ACC activation levels were present in more emotionally aware female participants when shown short 'emotional' video clips.<ref>{{cite journal | vauthors = Lane RD, Reiman EM, Axelrod B, Yun LS, Holmes A, Schwartz GE | title = Neural correlates of levels of emotional awareness. Evidence of an interaction between emotion and attention in the anterior cingulate cortex | journal = Journal of Cognitive Neuroscience | volume = 10 | issue = 4 | pages = 525–35 | date = July 1998 | pmid = 9712681 | doi = 10.1162/089892998562924 | s2cid = 27743177 }}</ref> Better emotional awareness is associated with improved recognition of emotional cues or targets, which is reflected by ACC activation.

The idea of awareness being associated with the ACC is supported by some evidence, in that it seems to be the case that, when subjects' responses are not congruent with actual responses, a larger [[error-related negativity]] is produced.<ref name=Luu04/>

One study found an ERN even when subjects were not aware of their error.<ref name=Luu04/> Awareness may not be necessary to elicit an ERN, but it could influence the effect of the amplitude of the feedback ERN. Relating to the reward-based learning theory, awareness could modulate expectancy violations. Increased awareness could result in decreased violations of expectancies and decreased awareness could achieve the opposite effect. Further research is needed to completely understand the effects of awareness on ACC activation.

In ''[[The Astonishing Hypothesis]]'', [[Francis Crick]] identifies the anterior cingulate, to be specific the anterior cingulate sulcus, as a likely candidate for the center of [[free will]] in humans. Crick bases this suggestion on scans of patients with specific lesions that seem to interfere with their sense of independent will, such as [[alien hand syndrome]].

===Role in registering pain===
The ACC registers physical pain as shown in functional MRI studies that showed an increase in signal intensity, typically in the posterior part of area 24 of the ACC, that was correlated with pain intensity. When this pain-related activation was accompanied by attention-demanding cognitive tasks (verbal fluency), the attention-demanding tasks increased signal intensity in a region of the ACC anterior and/or superior to the pain-related activation region.<ref>Davis, Karen D., Stephen J. Taylor, Adrian P. Crawley, Michael L. Wood, and David J. Mikulis. "Functional MRI of pain- and attention-related activations in the human cingulate cortex", ''J. Neurophysiol.'' volume 77: pages 3370–3380, 1997 [http://jn.physiology.org/content/77/6/3370.short]</ref> The ACC is the cortical area that has been most frequently linked to the experience of pain.<ref>{{cite book|last=Pinel|first=John P.J. | name-list-style = vanc |title= Biopsychology |year=2011 |publisher=Allyn & Bacon |location=Boston|isbn=978-0-205-83256-9|page=181|edition=8th }}</ref> It appears to be involved in the emotional reaction to pain rather than to the perception of pain itself.<ref>{{cite journal | vauthors = Price DD | s2cid = 15250446 | title = Psychological and neural mechanisms of the affective dimension of pain | journal = Science | volume = 288 | issue = 5472 | pages = 1769–72 | date = June 2000 | pmid = 10846154 | doi = 10.1126/science.288.5472.1769 | bibcode = 2000Sci...288.1769P }}</ref>

Evidence from social neuroscience studies have suggested that, in addition to its role in physical pain, the ACC may also be involved in monitoring painful social situations as well, such as exclusion or rejection. When participants felt socially excluded in an fMRI virtual ball throwing game in which the ball was never thrown to the participant, the ACC showed activation. Further, this activation was correlated with a self-reported measure of social distress, indicating that the ACC may be involved in the detection and monitoring of social situations which may cause social/emotional pain, rather than just physical pain.<ref>{{cite journal | vauthors = Eisenberger NI, Lieberman MD, Williams KD | title = Does rejection hurt? An FMRI study of social exclusion | journal = Science | volume = 302 | issue = 5643 | pages = 290–2 | date = October 2003 | pmid = 14551436 | doi = 10.1126/science.1089134 | bibcode = 2003Sci...302..290E | s2cid = 21253445 }}</ref>