Abstract: Current researches are largely concentrated on the characteristics of the activation of neural networks related to the autobiographical memory’s retrieval process with the technologies of fMRI and ERP; very few studies investigated the effects of emotion on the retrieval of autobiographical memory. Since the autobiographical memory has a distinct emotional characteristic, Will the retrieval processing of autobiographical memory be impacted by the emotion of the memory itself? An ERP study with the lexical decision task (LDT) was conducted to explore the effects of emotion on the implicit retrieval of the information from the autobiographical memory. The present study included two parts: the memory induced phase and the lexical decision task. Fifteen right-handed participants took part in this study; all were recruited from the university. In the memory induced phase, participants were asked to retrieve the positive、negative and neutral autobiographical memories according to the paired words (an emotional adjective - a neutral noun), these words were firstly assessed prior to the formal experiment. The nouns were evaluated again for their emotionality, importance and clarity on a 7-points scale after the retrievals. A relationship between the given nouns and the autobiographical memory was established, this relation would be used in the lexical decision task. The lexical decision task was conducted after the memory induced phase, in which participants needed to decide whether the item was a word or a pseudo-word by pressing the allocated keys. Each item was presented for 500ms and 2000ms was given to respond. The EEG was recorded while the items appeared. The results showed that participants successfully extracted three types of autobiographical memory with same degree of clarity, the positive and negative memories being more important than the neutral ones. The results of the lexical decision task revealed that the negative information of autobiographical memory triggered more positive ERP than the positive and neutral ones during 450~900ms. Although no difference was found between the positive and neutral information, significant difference existed between the negative information and the positive information, as well as between the negative information and the neutral information. This indicates that more cognitive resources are demanded for the retrieval of negative autobiographical memory. In short, we can conclude that the emotion does affect the implicit retrieval of the information from the autobiographical memory. It requires more cognitive resources in the retrieval of negative autobiographical memory than the positive and neutral autobiographical memories.

Key words: Autobiographical memory, ERP, emotion, lexical decision task