Abstract:

A large number of studies have revealed that memories not only easily fade away but also can occasionally be changed spontaneously; memory errors are everywhere, reminding us that memories are not an exact copy of the experienced events. The influences of the various types of stimulus and emotional states on false memories were first studied by using the classical DRM paradigm. Furthermore, we investigated the influence of time stress on mood-congruent false memories.
The first experiment was performed to identify the influences of different emotional stimuli on false memories under time pressure. The hybrid design method was used, namely, 2 (time stress: stress group and control group) × 3 (word titer: positive word, negative word, and neutral word). The between-subject variable was time pressure, the within-subject variable was word titer, and the dependent variable was the number of the false recognitions of the critical lures. The results of experiment 1 showed that the main effect was remarkable under time stress, as was the valence of words. The interaction between the time stress and valence of words was significant. The results demonstrated that the number of false recognitions for the subjects in the stress group with respect to the negative critical lures was much higher than were those of the neutral and positive ones.
The second experiment sought to uncover the influences of different emotional states on the false memory under time pressure. The design method of 2 (time stress: stress group and control group) × 3 (emotion titer: positive emotion group, negative emotion group, and neutral group) was used, and the dependent variable was the number of the false recognitions of the critical lures. The results of experiment 2 showed that the main effect was marginally significant under the time stress, and the emotion was significant. The interaction between time stress and emotion was significant. The results revealed that the false recognition for the subjects in the positive emotion group with respect to the critical lures had the largest number.
The third experiment utilized the hybrid design method of 2 (time stress: stress group and control group) × 4 (mood type: positive mood-congruency, negative mood-congruency, positive mood-inconsistency, and negative mood-inconsistency) to investigate the influences of time pressure on mood-congruent false memories, demonstrating that both the pressure group and the control group subjects showed a significant mood-congruent false memory. The results of experiment 3 showed that the number of false recognitions with respect to the mood-congruency for the subjects in the stress group and the control group were both higher than that of the mood-inconsistency, and the stress group had a larger number of false recognitions than did the control group under the condition of mood-congruency.
The results of three experiments show that time pressure has a positive effect on false memories and further promotes negative mood-consistency false memories. Individual negative emotions can undermine the generation of false memories under time pressure.

Key words: false memory, emotion, time pressure, mood-congruency