The implicit memory of individual depression in percept-driven process under the influence of sad mood induction

Abstract

Objective To investigate the effect of sad mood to implicit memory of depressed individuals under the condition of percept-driven process. Methods Using the percept-driven implicit paradigm improved by Paller,26 depression subjects and 25 normal subjects completed study-test task and reported the gender of different emotional faces. Results ①There were main effects of time(F = 4.61, P<0.05)and mood state(F= 21.61, P <0.05) ,significant interaction of time and emotion(F = 4. 13, P<0. 05) ,no significant difference of group on visual analogue scale(VAS) mood ratings. ②Among the accuracy rate of subjects' gender judging to different emotional faces,there were significant main effects on time(F = 4.12, P<0.05)and experiment type (F = 20.55, P < 0.05) , and there was significant interaction of time and experiment type (F=31.72,P<0.05). ③Further simple effects analysis showed that the positive((80 ± 13)%vs(92 ± 10)% , F=65.06, P<0.05) ,negative((58 ± 12)%vs(91 ±10)%,F=10.00,P<0.05),neutral((84±16)%vs(88±9)%, F= 12.49, P < 0. 05) faces when the presentation time was 3600ms in experiment type had significant simple effects; the positive ((76 ± 12)%vs(85±10)%,F=54.72, P<0.05) ,neutral((82 ± 10)% vs(80 ± 10)% , F = 54.57, P<0.05)faces when the presentation time was 300 ms in experiment types had significant simple effects, while the accuracy of neutral faces had significant simple effect between the two groups. Conclusion Sad mood enhance the implicit memory of both depressed and normal subjects to positive and negative faces,and the accuracy rate in implicit processing to neutral faces of depressed group were lower than that of normal group. Key words: Percept-driven test; Sad mood; Implicit memory; Explicit process; Implicit process