Attentional boost effect in conceptual implicit memory

Abstract

The attentional boost effect (ABE) was first discovered by Swallow in 2010, which means that when subjects perform coding and target detection tasks simultaneously, the memory performance of background information presented in target items is better than those presented in distracted items. Previous studies believe that this promotion effect is mainly due to the fact that target detection enhances the perceptual processing of background information; however, many experimental results contrary to this perceptual processing enhancement hypothesis indicate that “target detection does not necessarily promote the perceptual processing of background information.” Can target detection promote semantic processing? If so, why is ABE not found in the implicit test task of concepts that rely on semantic information? We speculate that this may be related to the encoding tasks used in these experiments. In reading words aloud, subjects may only perform perceptual coding but not conceptual coding. If the time-selective attention mechanism promotes cognitive processing simultaneously with target detection, ABE should appear in implicit conceptual tests when conceptual processing of words is performed simultaneously with target detection. This study adopts the classic ABE paradigm of Swallow and Jiang (2010) and further controls the different processing types of memory materials in the encoding stage to explore whether target detection promotes semantic processing of simultaneously presented background materials. In Experiment 1, lexical materials were used, and subjects were asked to read words aloud while performing target detection tasks in the encoding stage. Perceptual (true and false word judgment) and conceptual priming tests (semantic judgment) were then completed. The experimental design was a 2 × 2 in-subject design. Results showed that the ABE effect only appeared under the perceptual priming test condition, and the priming amount under the target condition was significantly greater than those under the distraction condition, while under the conceptual condition, the priming amounts under the target and distraction conditions were not significantly different. Based on Experiment 1, Experiments 2 and 3 used vocabulary and picture materials, respectively, to further control the processing types of memory materials in the coding stage, including perceptual (vocabulary structure judgment, presence of white in pictures) and semantic coding (vocabulary, picture pleasure judgment). A conceptual implicit test (semantic judgment) was then conducted to investigate whether the two coding methods have different effects on ABE in subsequent conceptual implicit tests to verify whether target detection promotes semantic processing of background materials presented simultaneously. The experimental design was a 2 × 2 in-subject design. Experiments 2 and 3 revealed that the ABE effect only appeared under the condition of semantic encoding but not under the condition of perceptual encoding. Results showed that in the dual-task processing, target detection can promote not only the perceptual processing of background information but also the semantic processing of background information. The promotion effect of target detection on background information is related to the processing of the background information. If the encoding process of background information under target detection is consistent with the extraction process that relies on in subsequent implicit tests, ABE will be generated.