The Episodic Memory Monitoring In Patients With White Matter Ischemic Lesions

Objective To investigate the episodic memory monitoring in patients with white matter ischemic lesions(WMIL) and explore the relevance of episodic memory disorder and memory monitoring and the possible mechanism.Method The feeling of knowing-episodic memory(FOK-EM) paradigm were adopted and subsequently administered in 30 WML patients and 30 control participants who were matched in age and educational level. The paradigm have three stages: 1. Learning stage: showing the 20 pairs of words in the center of the computer screen(15s), 20 minutes after learning to be recalled; 2. Cued recall and FOK judgment: showing the cue word(5s) to let the subjects recalled the target word, and the for FOK judgments.The answers have six levels, and the 1,2,3 grade records as a negative judgment, the 4,5,6 grade record as the affirmative judgment; 3. Recognition stages: the subjects must the find the target word from six words which is similer with the target word(5s). The datas will analysis in Goodman-Kruskal correlation analysis, and the value of Gamma is the FOK judgment accuracy. Addition, test results will be divided into four groups, Rreally Judgment/ Rreally Recognition(RR), Really Judgment/ False Recognition(RF), False Judgment/ Really Recognition(FR), False Judgment/ False Recognition(FF). The RF group is the overestimation group, and the FR group is the underestimated group.Results Compared with control group(cued recall 4.37±1.59;recognition 8.73±1.05), the episodic memory of WMIL patients were significantly impaired on the cued recall performance(3.30±1.51,t=2.666,P<0.05)and recognition performance(7.23±0.77,t=6.306,P<0.01).Furthermore,the accuracy of FOK judgment(-0.13±0.31), the correct judgment and correct recognition of FOM-EM(23.16±5.96%) and the correct judgment and false recognition of FOK-EM(34.26±7.65%) in the WMIL patients group were significantly different compared with the control group(the accuracy of FOK judgment:0.34±0.27,t=6.280,P<0.01;the correct judgment and correct recognition:35.12±6.82%,t=7.234,P<0.01;the correct judgment and false recognition:19.27±6.50%,t=-8.174,P<0.01). In addition,the correct judgment and false recognition performance was positively correlated with the severity of periventricular lesions and deep white matter lesions in the WMIL patients group(r=0.716,P<0.01;r=0.598,P<0.01).Conclusions The WMIL patients demonstrated an overestimation of their recognition ability of episodic memory, moreover,this impairment of memory monitoring was correlated with the deficit of executive function caused by the damage of the prefrontal-subcortical circuit,indicating that this mechanism could be an influential factor of episodic memory disorder in WMIL.