关键词:  内隐记忆, 外显记忆, 提取干扰, 双任务, 任务转换

Abstract:  A wide range of studies have shown that executing the other secondary task during encoding has little influence on implicit memory (repetition priming). Somewhat surprisingly, relatively few studies discussed the effects of interference on implicit memory during retrieval, which was confirmed as a process distinct from encoding, but also important in memory. Furthermore, an open question remains as to whether the retrieval interference could affect implicit memory? The effect of interference during retrieval was assessed by comparing a divide-attention (DA) condition, on which participants carried out a memory task (lexical decision) and an interference task (even-odd decision) simultaneously or successively, with a full-attention (FA) condition, on which participants performed only the memory task or interference task. Each experiment consisted of five parts: a study phase, a distraction phase, twice FA interference phases, and a retrieval phase, which included above two types attention conditions. Thirty-five undergraduate students participated in Experiment 1, which investigated whether synchronous interference task during retrieval could affect implicit memory. Experiment 2 further examined whether asynchronous interference could also change the priming of implicit retrieval. Thirty participants took part in Experiment 3, which was designed to examine whether such interference could affect explicit memory retrieval. Therefore, it replaced the lexical decision with recognition task based on Experiment 1. Participants were instructed to make response to corresponding items by pressing keyboard, and were told that the memory and interference task were equally important. They were asked to perform both tasks as quickly and accurately as possible. The Reaction Time (RT) and Accuracy data in retrieval phase were recorded, in order to assess priming effects, the effect of interference and interference task costs. The results showed that, first, the repetition priming results (the facilitation or bias in processing of studied items) were quite consistent across Experiment 1 and 2 both on RT and Accuracy. It reflected that priming would be impacted by interference task, whatever the distraction and memory stimulus presented synchronously or asynchronously. Second, In Experiment 3, there was non-significant difference across attention conditions in recognition Accuracy. Third, we followed Lozito and Mulligan’s (2010) method for examining interference task costs. They proposed two measures to obtain distracting task costs for verifying the effects of interference. One of them would work out global costs, which was assessed by comparing performance on the interference task when performed under DA to FA. We found global costs occurred among three experiments, indicating that attention resource competition happened across dual tasks. But significant specific costs, which comparing performance on interference among DA, was only found in Experiment 3, indicating that explicit retrieval would break secondary task performance, whereas, implicit retrieval seemingly has little impact on interference task, but easily influenced by interference task. In conclusion, results from the current study revealed that implicit memory priming could not be regarded as an automatic form of retrieval with ease. And it's necessary for memory retrieval to catch enough cognitive resources. If limited resource was occupied by the other task, implicit retrieval processing would be impacted.

Key words:  implicit memory, explicit memory, interference in retrieval, dual tasks, task switching