Editing Hypnosis (section)

=== Neuropsychology ===
Changes in brain activity have been found in some studies of highly responsive hypnotic subjects. These changes vary depending upon the type of suggestions being given.<ref>{{cite journal | vauthors = Raz A, Fan J, Posner MI | title = Hypnotic suggestion reduces conflict in the human brain | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 102 | issue = 28 | pages = 9978–83 | date = July 2005 | pmid = 15994228 | pmc = 1174993 | doi = 10.1073/pnas.0503064102 | bibcode = 2005PNAS..102.9978R| doi-access = free }}</ref><ref>{{cite journal | vauthors = Derbyshire SW, Whalley MG, Stenger VA, Oakley DA | title = Cerebral activation during hypnotically induced and imagined pain | journal = NeuroImage | volume = 23 | issue = 1 | pages = 392–401 | date = September 2004 | pmid = 15325387 | doi = 10.1016/j.neuroimage.2004.04.033 | s2cid = 16786564}}</ref> The state of light to medium hypnosis, where the body undergoes physical and mental relaxation, is associated with a pattern mostly of alpha waves.<ref>London College of Clinical Hypnosis. "What is Clinical Hypnosis?" [https://web.archive.org/web/20051101055303/http://www.lcch.co.uk/hypnotherapy.htm] . Accessed 14 September 2013</ref>{{Better source needed|date=September 2021}} However, what these results indicate is unclear. They may indicate that suggestions genuinely produce changes in perception or experience that are not simply a result of imagination. However, in normal circumstances without hypnosis, the brain regions associated with motion detection are activated both when motion is seen and when motion is imagined, without any changes in the subjects' perception or experience.<ref>{{cite journal | vauthors = Grossman ED, Blake R | title = Brain activity evoked by inverted and imagined biological motion | journal = Vision Research | volume = 41 | issue = 10–11 | pages = 1475–82 | year = 2001 | pmid = 11322987 | doi = 10.1016/S0042-6989(00)00317-5 | s2cid = 6078493| doi-access = free }}</ref> This may therefore indicate that highly suggestible hypnotic subjects are simply activating to a greater extent the areas of the brain used in imagination, without real perceptual changes. It is, however, premature to claim that hypnosis and meditation are mediated by similar brain systems and neural mechanisms.<ref>[http://mbr.synergiesprairies.ca/mbr/index.php/mbr/article/view/515 Functional neuroimaging studies of hypnosis and meditation: A comparative perspective] {{webarchive |url=https://web.archive.org/web/20121008034039/http://mbr.synergiesprairies.ca/mbr/index.php/mbr/article/view/515 |date=8 October 2012}}</ref>

Another study has demonstrated that a colour hallucination suggestion given to subjects in hypnosis activated colour-processing regions of the occipital cortex.<ref>{{Cite journal |last=Landry |first=Mathieu |last2=Lifshitz |first2=Michael |last3=Raz |first3=Amir |date=2017-10-01 |title=Brain correlates of hypnosis: A systematic review and meta-analytic exploration |url=https://linkinghub.elsevier.com/retrieve/pii/S0149763416306030 |journal=Neuroscience & Biobehavioral Reviews |series=The power of instructions: the influence of instructions on cognition, behaviour and physical states |volume=81 |pages=75–98 |doi=10.1016/j.neubiorev.2017.02.020 |issn=0149-7634}}</ref><ref>{{cite journal | vauthors = Kosslyn SM, Thompson WL, Costantini-Ferrando MF, Alpert NM, Spiegel D | title = Hypnotic visual illusion alters color processing in the brain | journal = The American Journal of Psychiatry | volume = 157 | issue = 8 | pages = 1279–84 | date = August 2000 | pmid = 10910791 | doi = 10.1176/appi.ajp.157.8.1279 | s2cid = 18060042 }}</ref> A 2004 review of research examining the [[EEG]] laboratory work in this area concludes:

{{blockquote|Hypnosis is not a unitary state and therefore should show different patterns of EEG activity depending upon the task being experienced. In our evaluation of the literature, enhanced [[theta wave|theta]] is observed during hypnosis when there is task performance or concentrative hypnosis, but not when the highly hypnotizable individuals are passively relaxed, somewhat sleepy and/or more diffuse in their attention.<ref>{{cite book|author=Horton |title=The Highly Hypnotisable Subject|date=2004|page=140 |author2= Crawford}}</ref>}}

Studies have shown an association of hypnosis with stronger theta-frequency activity as well as with changes to the [[gamma wave|gamma]]-frequency activity.<ref>{{cite journal | vauthors = Jensen MP, Adachi T, Hakimian S | title = Brain Oscillations, Hypnosis, and Hypnotizability | journal = The American Journal of Clinical Hypnosis | volume = 57 | issue = 3 | pages = 230–53 | date = January 2015 | pmid = 25792761 | pmc = 4361031 | doi = 10.1080/00029157.2014.976786 | type = Review}}</ref>{{Primary source inline|date=September 2021}} [[Neuroimaging]] techniques have been used to investigate neural correlates of hypnosis.<ref>{{cite journal | vauthors = Mazzoni G, Venneri A, McGeown WJ, Kirsch I | title = Neuroimaging resolution of the altered state hypothesis | journal = Cortex; A Journal Devoted to the Study of the Nervous System and Behavior | volume = 49 | issue = 2 | pages = 400–10 | date = February 2013 | pmid = 23026758 | doi = 10.1016/j.cortex.2012.08.005 | s2cid = 206984627 | url = https://strathprints.strath.ac.uk/44493/ | type = Review | access-date = 21 July 2021 | archive-date = 14 June 2021 | archive-url = https://web.archive.org/web/20210614142638/https://strathprints.strath.ac.uk/44493/ | url-status = live }}</ref><ref>{{cite journal | vauthors = Landry M, Raz A | title = Hypnosis and imaging of the living human brain | journal = The American Journal of Clinical Hypnosis | volume = 57 | issue = 3 | pages = 285–313 | date = January 2015 | pmid = 25928680 | doi = 10.1080/00029157.2014.978496 | s2cid = 844244 | type = Review}}</ref>

The induction phase of hypnosis may also affect the activity in brain regions that control [[intention]] and process [[Emotional conflict|conflict]]. Anna Gosline claims:

{{blockquote|Gruzelier and his colleagues studied brain activity using an [[fMRI]] while subjects completed a standard cognitive exercise, called the [[Stroop task]]. The team screened subjects before the study and chose 12 that were highly susceptible to hypnosis and 12 with low susceptibility. They all completed the task in the fMRI under normal conditions and then again under hypnosis. Throughout the study, both groups were consistent in their task results, achieving similar scores regardless of their mental state. During their first task session, before hypnosis, there were no significant differences in brain activity between the groups. But under hypnosis, Gruzelier found that the highly susceptible subjects showed significantly more brain activity in the [[anterior cingulate gyrus]] than the weakly susceptible subjects. This area of the brain has been shown to respond to errors and evaluate emotional outcomes. The highly susceptible group also showed much greater brain activity on the left side of the [[prefrontal cortex]] than the weakly susceptible group. This is an area involved with higher level cognitive processing and behaviour.<ref>{{cite magazine|last=Gosline|first=Anna| name-list-style = vanc |magazine=New Scientist|url=https://www.newscientist.com/article.ns?id=dn6385|date=10 September 2004|title=Hypnosis really changes your mind|access-date=2007-08-27}}</ref><ref>{{cite journal | vauthors = Egner T, Jamieson G, Gruzelier J | title = Hypnosis decouples cognitive control from conflict monitoring processes of the frontal lobe | journal = NeuroImage | volume = 27 | issue = 4 | pages = 969–78 | date = October 2005 | pmid = 15964211 | doi = 10.1016/j.neuroimage.2005.05.002 | s2cid = 13979703}}</ref>}}