I-DMN kunye neNxibelelwano esebenzayo
Ukucatshulwa kwe-resonance magnetic (i-FMRI) esebenzayo isebenza ukuba senze inkcazo kwimisebenzi yobuchopho kubantu abaphila ngokusekelwe kwimifanekiso ephosakeleyo. Kwelinye, kuye kwasenza sikwazi ukubeka izimvo ezibalulekileyo kwiintanethi zengqondo ezivela ngokwemvelo, kubandakanywa nenethiwekhi yendalo. Ukuze uqonde amanxibelelwano anjalo, nangona kunjalo, imvelaphi ethile ekuxhumeni komsebenzi iyadingeka kuqala.
Yintoni efanelekileyo yokudibanisa iMRI?
Izifundo ezininzi ze-FMRI zenziwa ngelixa isigulane senza umsebenzi othile. Ngokomzekelo, ukuba bayichukumisa iqhosha ngesandla sabo sokunene, ungabona kamva inxalenye ye-hemisphere ekhohlo kufuphi ne-motor cortex ukukhanya ngelo xesha.
Enye indlela kukujonga ingqondo xa isisebenzi sokuzithandela singenzi lutho nakwi-scanner-nje silele apho. Ngamanye amaxesha ubugcisa bubizwa ngokuthi "ukuphumla kombuso" i-FMRI.
Ngelixa silala apho, iindawo ezihlukeneyo zobuchopho zinezinto ezihamba phambili, ezithetha amaza ombane anxulumene nomqondiso weMRI. Ngamanye amaxesha, la maza asesigxina kunye nomnye nomnye, oko kuthetha ukuba batshabalalisa phezulu kunye neengqungquthela zesimo sokutshintsha ngexesha elifanayo. Kancinci nje ukuba ngaba ngamalungu ahlukeneyo omculo odlala umdlalo omnye xa elandela umqhubi ofanayo. Ezi ndawo zimbini zithi zixhunyiwe ngokusebenzayo.
Ukuqhagamshelana okusebenzayo akumele kulinganiswe ngokuphumla. Imisebenzi enjengokubeka ingqwalasela into ebalulekileyo ingatshintsha iipatheni zokuxhumeka komsebenzi kuzo zonke iingqondo.
Ukuhlanganiswa okusebenzayo akuthethi ukuba iindawo ezimbini zobuchopho zixhomekeke ngqo kwaye zixhunyiwe ngokomzimba. Ngokomzekelo, indawo ezimbini zobuchopho zingase zihluke kakhulu, kodwa zombini zifumana iimpawu ezisuka kwingingqi yengqondo efana ne-thalamus.
Ezi zinokuthi zidibaniswe ngokusebenzayo ukuba iimpawu zazo zikhompyutheni.
Ukuzisa iNethiwekhi yeNdlela engapheliyo
Ngaphezulu kweminyaka elishumi edlulileyo, ukunyuka kwengqalelo kuye kwahlawulwa kule nxibelelwano esebenzayo njengendlela yokufumana amanethiwekhi kwiingqondo ezinxulumene nemisebenzi ethile, kuquka ukuphumla nje. Enye yeenethiwekhi ezigqwesileyo eziza kuxoxwa yinkqubo yokungagqibekanga yenethiwekhi.
Igama elithi "imodeli engagqibekanga" yaqala ukusetyenziswa nguDkt. Marcus Raichle ngo-2001 ukuchaza umsebenzi wokuphumla kwengqondo. Kwakuye kwaphawula ukuba ngaphambili "ukuphumla" kwengqondo kusebenzisa amandla amaninzi kunokuba ingqondo ikwenza "umsebenzi osebenzayo", ebonisa ukuba mhlawumbi ingqondo "ayiphumuli" kakhulu njengoko itshintsha uhlobo lomsebenzi apho lusebenza khona zibandakanya.
Inethiwekhi engapheliyo yenethiwekhi (i-DMN) ibandakanya ukuchithwa kwe-frequency-frequency of one-fluctuation per second. Inethiwekhi iyasebenza xa ubuchopho buphumla. Xa ubuchopho bujoliswe kumsebenzi okanye kwinjongo, inethiwekhi engagqibekanga iyacima.
Kukho, ngokwenene, kubekho inethiwekhi engapheliyo enye yenethiwekhi-into esiyibiza ngokuthi i-DMN inokuthi ibe yinto yokuqokelela amanethiwekhi amancinci, nganye iyazinikezelwa into ethile eyahlukileyo kunomnye. Nangona kunjalo, iinkalo ezithile zobuchopho ngoku ziqondwa ukuba ziyinxalenye ye-DMN.
Ziziphi Iingxenye Zobuchopho Zise-DMN?
Iingingqi zengqondo ezibandakanyiweyo kwinethiwekhi yendlela engapheliyo zibandakanya i-lobe yexesha eliphakathi, i -cortex ye-preferenceal , kunye ne-cortex yangemva, kunye neengqungquthela ze-parietal cortex. Yonke le mimandla idibene nenxalenye ethile yengcamango yangaphakathi. Ngokomzekelo, i-lobe yexesha elidityanisiweyo idibene nomemori . I-cortex ye-preference ye-prefrontal idibene nenkolelo yengqondo, ukukwazi ukubona abanye njengengcinga kunye neemvakalelo ezifana neyakhe. I-posterior cingulate icingelwa ukuba ibandakanye iintlobo ezahlukeneyo zeengcamango zangaphakathi.
Iirror neurons ziye zafunyanwa ukuba zisebenzisane ne-DMN.
Yintoni eyenziwa yi-DMN?
Ngenxa yokuba inethwekhi yenethiwekhi engagqibekanga iyasebenza kakhulu kwaye ngenxa yezakhiwo ezibandakanyekayo, abanye abantu baye bafaka ukuba kudibaniswa nengcamango engenangqondo, kuquka imisebenzi efana nokuhlaziya okanye ukubuyisa izikhumbuzo. Abanye bacebise, nangona kunjalo, ukuba umsebenzi unokuthi unxulumene neenkqubo zemizimba engahambelani nanoma yimuphi umsebenzi othile-nokuba uphumule-nangona le ngcamango ibonakala ingaphumeleli.
Utshintsho kwinkqubo yenethiwekhi engagqibekanga idibene nenani elibanzi lwezifo ezahlukileyo, kuquka nesifo se-Alzheimer, i-autism, i-schizophrenia, i-bipolar disorder, i-post-traumatic stress disorder, ukuxinezeleka, nokunye. Izifo zingabangela umsebenzi omncinci okanye kakhulu, kwaye ngamanye amaxesha idatha iyahluka ngokubhekiselele ekuyiyo eyenzekayo. Ingaba oku kubonakalisa ukuqonda okungahambi kakuhle kwesi sifo, ubuchule, okanye zombini ahlale engaqiniseki.
Esinye sezigxeko eziye zavela malunga ne-DMN kukuba ukuba utshintsho ngaphakathi kuyo kubonakala kungabonakaliyo - yintoni umlinganiselo umlinganiselo ukuba awukuxeleli ngokwenene ukuba yintoni ingxaki? Abanye baye babuza ukuba umnxibelelwano unengqiqo ebonakalayo, nangona nje ngokuba uphando lubangele ukuhlaziywa kwezinto eziphilayo ze-DMN kuba nzima ukubuza.
Amanye amanxibelelwano, afana nalawo anxulumene nokuqwalasela, umbono kunye nokuva, sele kuchazwe. Nangona iingeniso zonyango zale nethiwekhi zihlala zingacacanga, zingabonakalisa utshintsho olubalulekileyo kwindlela esicinga ngayo ngengqondo, kwaye ngubani na ongathi apho ukucinga okunjalo kuya kusithatha kwixesha elizayo?
> Imithombo:
> Buckner, RL; U-Andrews-Hanna, JR; Schacter, iDL (2008). "Inethiwekhi ye-Brain Default": i-Anatomy, Umsebenzi, kunye nokuBheka kweZifo ". Iziganeko zeNew Academy of Science 1124 (1): 1-38.
> Fair, DA; Cohen, AL; IDosenbach, i-NUF; Icawa, iJA; Miezin, FM; Barch, DM; URaichle, ME; Petersen, SE et al. (2008). "Ukwakhiwa kwezakhiwo zobuqhetseba obunokutshintsha kweengqondo". Iinkqubo zeSizwe seSizwe seSayensi 105 (10): 4028-32.
> Raichle, uMarcus E .; Snyder, Abraham Z. (2007). Imodi engapheliyo yomsebenzi wengqondo: Imbali emfutshane yembono eguqukayo ". I-NeuroImage 37 (4): 1083-90.