Access And Elabration Stages Of Recent Autobiographical Memory In Depression: An FMRI Research

Depression is a severe disabling major public mental health disorder, with a highprevalence. However, the pathogenesis is too complex to clear up until now. It the view ofcognitive processing theory there is negative cognitive schemata in the depressiveindividuals, that is negative bias of cognitive processing in attention, memory and so on.,causing and maitaining the syptoms of depression. And memory is a key part in theoccurance and maintenance of depression. Many studies have recently concerned about thedepression from the perspective of the autobiographical memory, finding that the depressiveindividuals have a tendency to recall their past personal life events lack of details orcategorized repeated memory, that is overgeneral autobiographical memory. Overgeneralautobiographical memory is considered to be a robust phenomenon in depression.It often shows the contradiction and inconsistency when comparing the results of thefindings on overgeneral autobiographical memory mechanism in depression or curativeeffect to depression through the autobiographical training. It is probably because of someother variables not excluded from autobiographical memory researches.For example, thetime effect could affect the result if remote memory and recent memory could not beseperated from each other.It is shown in many researches that autobiographical memory is different between thedepressive and the normal groups. Over general memories is increasing while specificmemory retrieval is impared. So whether is the difference above caused by differenct brainactivation patterns for different peroids of autobiographical memory or various neuralstructure supporting access and elaboration stages of autobiographical memory or not? Andwhat are the brain activation patterns for access and elaboration stages of autobiographicalmemory? Few research givcs the relevant reports.So in this research further purification to stimulus should be carried out on the basis ofour further research. Classical Autobiographical Memory Test is adopted to elicitautobiographical memory retrieval by the subjects in depression. Futhermore, fMRI is used to detect the brain activation characteristics during the access and elabration stages of recentautobiographical memory retrieval to further illustrate overgeneral autobiographical memorymechanism in depression. And some outcomes and conclusions are shown as follows:1. There is a significant difference between the numbers of the recent specific memoryand the recent general autobiographical memory, elicited by cue words and classical AMTparadigm in the normal and depression groups (p<0.00). The number of recent specificmemory in the normal group is more than that in the depression group, while the number ofrecent general autobiographical memory in the depression group is much more.2. There are significant differences between brain activations of recent specificmemory and recent general memory retrieved by the normal group (p<0.05). During theprocess of recent specific memory retrieval, the activated brain areas include bilateralsuperior frontal gyrus, right medial frontal gyrus, left precuneus, left middle occipital gyrus,right postcingulate cortex and so on. And bilateral middle frontal gyrus are activated whenretrieving recent general memory.3. There are significant brain area activation differences between the normal anddepression groups when retrieving recent specifical autobiographical memory (p<0.05). Thebrain areas that the activation intensity in the normal group is stronger than that in thedepression group mainly include right middle occipital gyrus, right middle frontal gyrus,right medial frontal gyrus, left middle temporal gyrus and right fusiform gyrus, while onlyleft middle frontal gyrus activates much more strongly in the depression group.4. There are significant brain area activation differences between the normal anddepression groups when retrieving recent general autobiographical memory (p<0.05). Thebrain areas that the activation intensity in the normal group is stronger than that in thedepression group mainly include right middle occipital gyrus, right paracentral lobule, rightmiddle frontal gyrus, left middle temporal gyrus, right precentral gyrus, right inferior frontalgyrus, while left inferior frontal gyrus, right insula lobe activate much more strongly in thedepression group.5. There are significant differences between the access and the elabration period whenthe normal group individuals retrieve recent autobiographical memory (p<0.05). The brainareas that the activation intensity in the access period is stronger than that in the elabrationperiod mainly include left middle frontal gyrus, left superior frontal gyrus, left inferior frontal gyrus, left precentral gyrus, left middle temporal gyrus, left anterior cingulate cortex,left retrosplenial cortex and right putamen, while right insula, right middle occipital gyrusand right inferior frontal gyrus activate much more strongly in the elabration period.6. There are significant differences between the access and the elabration period whenthe depression group individuals retrieve recent autobiographical memory (p<0.05). The brainareas that the activation intensity in the access period is stronger than that in the elabrationperiod mainly include right inferior frontal gyrus, right middle frontal gyrus, right insulagyrus, right cingulate cortex, right lingual gyrus, left parahippocampus and right caudatenucleus, while only left insula activates much more strongly in the elabration period.7. There are significant differences between the normal and depression groups in theactivated brain areas of the recent autobiographical memory during access period (p<0.05).The brain areas that the activation intensity in the normal group is stronger than that in thedepression group mainly include right superior temporal gyrus, post cingulate cortex, rightinferior frontal gyrus, left middle frontal gyrus, right medial frontal gyrus, left postcentralgyrus, right fusiform gyrus and left caudate nucleus, while only left middle occipital gyrusactivates much more strongly in depression group.8. There are significant differences between the normal and depression groups in theactivated brain areas of the recent memory during elabration period (p<0.05). The brainareas that the activation intensity in the normal group is stronger than that in the depressiongroup mainly include right inferior frontal gyrus, left superior frontal gyrus and right middleoccipital gyrus,while left medial frontal gyrus and right superior temporal gyrus activatemuch more strongly in depression group.9. Hippocampus fails to activate during recent memory retrieval by normal groupindividuals, which could not support standard consolidation model, which oppinion is thathippocampus plays a key role in recent memory retrieval. However, that retrosplenial cortexis activated significantly, consistent with some other researches, indicates this brain areamay be relevant to recent memory retrieval.In summary, the activated brain areas differ in normal and depressive groups during thetwo stages of access and elabration, which may lead to different psychological meaning.