Perceptual Sensitivity Of Facial Expressions In Subthreshold Depression

Subthreshold depression(SD)refers to the individuals who have the significant depressive symptoms but without fulfilling the criteria for Major Depressive Disorder(MDD).Nowadays,subthreshold depression is widespread in society,has a high risk to develop into MDD and affects patients’ quality of life and social function.Emotional perception sensitivity means the ability of individuals to percept and recognize emotional information.Accurately and fastly perceiving the facial expressions of others will help people establish good social relationships and improve the quality of life.Previous studies have shown that the facial expression perception sensitivity of depressed individuals has changed.However,few researches have tried to explore the characteristics of facial expression perception sensitivity of subliminal depressed individuals.Therefore,the goal of the present study was to conduct two experiments to explore the conscious and unconscious perception sensitivity to facial expressions in SD by comparing NC group and SD group,as assessed using.The Beck Depression Inventory-II(BDI-II)and the Center for Epidemiological Studies Depression Scale(CESD)were used to survey 2184 college students.After two rounds of screening,77 participants were chosen to participate experiment 1,32 participants were assigned to the SD group and 45 participants were assigned to the non-depressed controls(NC)group.Moreover,92 participants were chosen to participate the experiment 2,45 participants were belonged to SD group and 47 participants were belonged to NC group.Experiment 1 used the QUEST adaptive staircase procedure to explore the facial expressions perception sensitivity of subthreshold depressed individuals to five expressions(happy,sad,angry,neutral and fear).Futhermore,a longitudinal design was used to investigate whether the facial expression perception sensitivity of SD could remain stable over time.Based on the results of experiment 1,we only used three facial expressions in experiment 2(happy,sad and neutral).There are total two tasks in experiment 2.Task 1 used the combination of masking paradigm and signal detection theory to explore the perception sensitivity of facial expressions in SD individuals at the level of consciousness.Task 2 used the break continuous flash suppression paradigm to explore the facial expression perception sensitivity of subthreshold depressed individuals at the level of unconsciousness.All data were analyzed in SPSS software.In experiment 1,results showed that compared with the NC group,the SD group had a lower recognition threshold for sad expression,but the abnormality would change over time.At the same time,we also found that the recognition threshold to sadness at the initial test can predict the changes of depression scores.In experiment 2,at the level of consciousness,NC group had a better discrimination than SD group in happiness.However,at the unconscious level,there was no significant difference between the two groups in all expressions.the current study indicated that perceptual sensitivity of facial expressions in subthreshold depression was impaired in conscious processing,which mainly reflected the stronger perceptual sensitivity to sad face and lower perceptual sensitivity to happy face.There was no impairment in the unconscious processing of subthreshold depression.