The Relationship Between Encoding And Retrieval Of Implicit And Explicit Memory

Implicit memory and explicit memory are two distinct memory systems underlying different neural substrates. By manipulating some factors during encoding such as depth of processing, divided attention, interference, study-to-test modality changes, and age, many researchers have found that these factors had different effects on implicit and explicit memory, which confirms the dissociation between these two forms of memory. But those experiments failed to consider factors that manipulates during retrieval, and their influences on the retrieval processes. Encoding and retrieval are two important phases of memory. Encoding produces memory en-gram and retrieval reactivates previously encoded information. So the consideration of retrieval manipulation is meaningful, which makes us know more about retrieval processes or the relationship between encoding and retrieval.As for explicit memory, the relationship of encoding and retrieval has been investigated by many researches with divided attention paradigm. These researchers have found out that the performance of a secondary task during encoding reduced the later memory performance, but dividing attention in the same way during retrieval had virtually no effect on memory performance, which confirmed asymmetry between encoding and retrieval processes. But with respect to implicit memory, we know little about these issues with few experimental studies. It's well known that the neural correlates of implicit and explicit memory are dissociated, and the effect of encoding manipulation on implicit and explicit memory is different. And then we proposed that the effect of retrieval manipulation on these two memory systems be different too. With that, there may be asymmetry between encoding and retrieval processes in implicit memory, but different from that in explicit memory.In order to explore these issues, one behavior experiment and two ERP experiments were conducted with Chinese characters as stimuli, and undergraduate students as subjects. These experiments adopted a study-to-test paradigm, in which participants performed a "shallow" (color) study task or a "deep" (pleasant) study task, followed by either a lexical decision (implicit) test or a recognition (explicit) test. An interference task was asking participants to account the total number of "+" in a regulated orientation which appeared with word, which was performed concurrently with either the encoding or the retrieval phase of the memory task.These experiments showed that: (1) the effects of interference at encoding on the performance and ERP in implicit memory test were different from that at retrieval. The performance of a concurrent task during encoding had no effect on later lexical decision performance, but interference during retrieval disrupted...