Characteristics Of Subjective Cognitive Decline(SCD):Evidence From Negative Psychological Characteristics And Negative Cognitive Biases

Alzheimer's Disease(AD)is the most common cognitive disorder in the elderly of Alzheimer's Disease,which seriously affects the quality of their lives.The irreversibility of its development makes researchers pay increasing attention to its early stage.Subjective Cognitive Decline(SCD)refers to self-perceived cognitive abilities which are lower than they used to be,but the objective examination results are within the normal range.This stage is considered by some scholars to be the earliest stage of AD development,but there is still great controversy among researchers.According to current researches,the difference between SCD and normal elderly basically lies in the subjective complaint of cognitive decline,namely subjective cognitive decline.However,is this complaint due to individual's real cognitive decline,or it is due to the influence of individual's personality,attitude to age,coping style and other psychological factors which result in reporting cognitive decline? Therefore,relevant influence factors on subjective cognitive decline were explored through qualitative research first,and then they were verified and quantified them through empirical researches to describe group characteristics of SCD.Study 1 randomly recruited 13 elderly people and adopted semi-structured interviews of qualitative research to collect data.Through three level coding analysis,19 nodes associated with subjective cognitive decline were found,including “passive helpless”,“maintenance state”,“loneliness dissatisfaction”,etc.They were encoded as psychological tendency(aging attitude and coping style)personality characteristics(personality traits and emotional traits),and cognitive biases(attention preference and memory preference).Personality characteristics and psychological tendency belongs to psychological characteristics and cognitive biases belongs to psychological process.Through source analysis,it is found that the elderly with subjective cognitive decline have negative psychological characteristics and negative cognitive biases.Study 2 attempted to discuss the negative psychological characteristics of SCD with the method of questionnaire research.114 elderly subjects were recruited anddivided into Health Control(HC)Group,Subjective Cognitive Decline(SCD)Group and Mild Cognitive Impairment(MCI)Group according to cognitive test results.Participants completed Big Five Personality Scale-Neuroticism Subscale,the Philadelphia Geriatric Center Morale Scale,and Simple Coping Style Questionnaire to measure their negative personality characteristics and psychological tendency.The results showed that: negative personality characteristics and negative psychological tendency are significantly positively correlated with subjective cognitive decline scores.Specifically,SCD and neuroticism score,anxiety,anger hostility,depression,interpersonal sensitivity,impulsivity,agitation,lonely discontent,aging attitude,negative coping is significantly positively correlated,while no significant correlation between SCD and vulnerability.There is negative correlation between objective cognitive score(MoCA)and neuroticism score,anxiety,depression,interpersonal sensitivity,impulsivity and anger hostility,vulnerability,agitation,lonely discontent,aging attitude and negative coping in the face of the irrelevant.There were also significant differences among the groups in the variables which significantly positive related to subjective cognitive decline.Post-test found that there were differences in the scores of above variables between SCD and HC group,but no significant differences between SCD and MCI.In study 3,negative cognitive biases of SCD were investigated by experiments,and the confounding effects of objective cognitive ability were distinguished.All of the 91 participants in study 3(three groups)were from study 2 and a mixed experimental design of group(between subjects)and lexical type(within subjects)was adopted.Afterward,each group completed the emotional Stroop task and the free recall task to measure their attentional bias and memory bias.The results showed: 1)In the attentional bias experiment,there were significant differences in the accuracy and reaction time of the three groups.The accuracy and the reaction time of MCI group was significantly lower and longer than that of SCD group and HC group,but there was no significant difference of the accuracy and reaction time between HC group and SCD group.In terms of positive and neutral words,there was no significant difference between HC group and SCD group in the reaction time;While in terms of negative words,the reaction time of SCD group was significantly longer than that of HC group;In all kinds of vocabulary,MCI group showed the longest response time.2)In the memory bias experiment: In terms of negative words,the amount of recall in SCD group was significantly higher than that in HC group.In terms of neutral words,there was no significant difference between HC group and SCD group;MCI recall was significantly the lowest in positive words,negative words,and neutral words.To sum up,the following conclusions can be drawn:(1)qualitative study found 19 nodes associating with subjective cognitive decline,including “passive helplessness”,“maintenance state”,“loneliness dissatisfaction”,etc.,which belonged to aging attitude,coping styles,personality traits,emotional quality,attention preference and memory preference.The first four aspects were as the psychological characteristics and the other aspects were cognitive process.Negative psychological factors came from the elderly with subjective cognitive decline.(2)Subjective cognitive decline was significantly positively correlated with negative personality characteristics(neuroticism,anxiety,anger hostility,depression,interpersonal sensitivity,impulsivity,agitation,lonely discontent)and negative psychological tendency(aging attitude and negative coping style).SCD individuals showed significant differences in the above negative psychological characteristics compared with the normal elderly,but no significant differences with MCI individuals.(3)Compared with the normal elderly,SCD individuals have negative attentional and memory bias.MCI individuals cannot confirm the existence of attention and memory bias due to excessive cognitive decline.