真实记忆与虚假记忆中的生命性效应研究

The Animacy Effect in True and False Recognition Memory

本研究采用DRM范式,探讨了生命性对真实和虚假记忆的影响。实验1使用类别呈现词语强化类别加工,实验2伪随机呈现词语弱化类别加工并进行即时及延时探测。结果发现:(1)当强化类别加工时,生命性和类别对击中率有相类似的促进效应;(2)当弱化类别加工并进行即时探测时,生命性对击中率的促进作用最强;(3)类别效应促进真实记忆和虚假记忆,但生命性效应仅促进了真实记忆,而不影响虚假记忆的产生;(4)在即时与延时探测中均发现类别效应和生命性效应。本研究证明了:(1)生命性效应的作用机制不同于类别效应;(2)生命性效应对真实和虚假记忆的作用机制不同;(3)类别效应和生命性效应的存在时效长达24小时,但是生命性效应的衰退速度较快。

Purposes： The animacy effect refers to the positive influence of animate stimuli on memory. This effect is found in free recall, recognition and cued recall tasks. Some researchers put forward the animate monitoring hypothesis, assuming that animate stimuli probably attract more attention and get better remembered. However, other researchers argued that the organizational structures of animate stimuli led to the animacy effect, which was known as the categorical hypothesis. It is not clear about the difference between the effects of animacy and category on true and false memory. Thus, the present research discussed the mechanism underlying the animacy effect and tried to distinguish the difference between the effects of animacy and category on true and false recognition memory. Moreover, this research examined bow long the two effects could last. Procedures： The research included two experiments. The materials were the same in the two experiments, including 30 words for animate things, fruits and inanimate things in multiple categories, respectively. There were 24 subjects in the experiment 1 and 56 subjects in the experiment 2. Experiment 1 examined the memory advantage of animacy under the situation where the stimuli were presented by blocks according to their category attribute （e.g., presenting all animate things and then all fruits） and the orders were counterbalanced. Experiment 2 examined the memory advantage of animacy under the situation where the stimuli were presented pseudo-randomly to prevent the same category attribute to appear in succession. This manipulation could prevent the subjects from using the categorical encoding strategy. In order to examine how long the effects last, the final recognition test was taken immediately after the distractor phase or one day after learning in experiment 2. Both experiments consisted of three phases： study phase, distractor task phase and test phase but the distractor task phase was replaced by a 24-hour interval in the delayed-test group in experiment 2. During the study phase, participants were asked to remember the words presented in the center of the screen, each for 3s after a fixation for 800ms. Then the participants finished a 5-min distractor task in which they made mathematical calculations, followed by a recognition task. For the recognition task, the participants were instructed to recognize the just-studied and new lists of words and the words would not disappear until participants responded. Results： （1） When the categorical attribute was apparent, the effects of animacy and category on true recognition memory were equivalent. （2） When the categorical attribute was not apparent and the recognition test was taken immediately, the effect of animacy on true recognition memory was the strongest. However, when the final recognition test was taken one day after learning, the effects of animacy and category on true recognition memory were equivalent again. （3） The category effect facilitated true recognition memory and created more false recognition memory while the animacy effect only facilitated true recognition memory. （4） The category effect and animacy effect were both found in the immediate-test group and delayed-test group. Conclusions： （1） The mechanisms underlying the category effect and animacy effect are different. （2） The mechanisms of the animacy effect on true and false memory are different. （3） Both the category effect and the animacy effect can last for more than 24 hours but the animacy effect declines faster.