The Mechanism Of Dual-stage Modulation In The Contextual Cueing Effect

Previous research has shown that participants respond faster to a target if it is always presented at the same location when accompanied by the same contextual configuration than if it is not (contextual cueing effect, Chun & Jiang,1998). To reveal the mechanism of this effect, researchers varied the set size and compared the search slopes and intercepts in repeated contexts with those in the non-repeated contexts. If the contextual cueing effect were the result of directing attention to the target (attentional guidance), there would be a downward trend in the search slope over the course of the experiment and such a downward trend should be more prominent for repeated display. In contrast, if contextual cueing was accounted for by perceptual-recognition processing or response priming, the intercepts would decrease over time. Behavioral responses obtained by different researchers (including ours) revealed through reaction time measure tended to be mixed. Some studies have suggested that contextual cueing is driven by the deployment of attentional guidance(M. M. Chun & Jiang,1998). Some studies considered that contextual cueing acts, at least in part, by speeding responses to targets in a familiar context(Melina A. Kunar, Flusberg, Horowitz, & Wolfe,2007).Therefore, analyzing the slope and intercept of the fitting model is not effective in revealing how the contextual cueing effect comes into being. One possible reason is that the search slope can only reflect the average behavior over the course of the experiment or a block of trials. Thus, response times cannot be used to determine the factors that affect the steepness of the slopes. With regard to the presumed line-fit model of contextual cueing, it is generally hypothesized that the decrease in the search slope should be attributed to the reduction of the average reaction time when searching for each item. However, studies have confirmed that during searching processes in predictive configurations, subjects only need to search through a few visual items before accurately locating the target's position.Consequently, in order to obtain a better understanding of how contextual cueing was elicited in the course of dynamic learning acquisition, the experiment reported here, used eye movement records to explore whether contextual modulation can be developed in different processing systems. It is well-known that the eye tracking system can be used to infer movement-to-movement cognitive processes in a fairly direct manner. Hence, by means of eye-movement recordings, contextual cueing can be better investigated in detail during different processes(Matthew S. Peterson & Arthur F. Kramer,2001). The present study intends to explore the covariation of the contextual cueing effect in different processes while recording specific ocular indices; we addressed the process by which contextual cueing effect would be elicited.In Exp 1., we used eye-movement records to explore the mechanism of contextual cueing effect. A 2(configuration: Predictive vs. Random)×7(1-7epoch,four adjoining blocks were grouped into one epoch)×2(set size:8 and 12) within subject design was conducted.The results showed that repeated configurations modulate eye-movement indices corresponding to different stages of cognitive processing. This suggests that the contextual cueing effect should reflect a dual-stage modulation of attentional guidance and response selection. We selected the following oculomotor parameters to reflect the nature of eye movements in this task:initial saccade latency (IL), number of saccade (SN), scan pattern ratio (SPR), distance between first eye fixation and the target after display onset, D(first fix, T), and time between last eye fixation and response though the button press (TLF to BP). Results from the reaction times revealed that the subjects'search performance improved significantly due to predictive configurations. However, the fit-line analysis in our data showed that the search slope decreased for predictive configurations than compared to random ones; however, no downward intercepts were detected. The current study used stimuli similar to that of Kunar et al.(Melina A. Kunar, et al.,2007), but it replicated work done by Chun and Jiang(M. M. Chun & Jiang,1998).Moreover, The analysis of the data of eye movements showed that for different cognitive processes, ocular indices in predictive configurations were remarkably superior to those in random ones. According to the ocular parameters of initial latency and TLF to BP, we partition the response RTs into three parts—the early phase, the middle phase and the late phase. Specifically, for the early phase, we consider that the initial latency (before any eye movement is made) is related to perceptual-recognition. For the late phase, we consider the TLF to BP as the duration for the response-selection. For the middle phase, we consider that the remaining duration (obtained by subtracting the initial latency and TLF to BP from the overall RT) is related to attentional guidance. The results of the three partition phases seems to suggest that the contextual cueing effect could be driven in both middle phase and late phase. Hence, the present results suggest that predictive configurations should influence both the processes of directing attention and decision processing involving selection. Hence, the dual-stage modulation assumption that contextual cueing affects attentional guidance and response-selection processing should be made more reasonable.In Exp 2., we adopted new stimuli that manipulated the physical disparity between the target item and the distractors as well as the discriminative difficulty of target item. Two color disparity (High-disparity vs. Low-disparity) between target item and the distractors were presented so as to vary the attentional guidance of the target. In such a pop-out visual search task, the target with a high color disparity would capture focal attention more efficiently than that with a low color disparity. Concurrently, discriminate difficulties were manipulated for the response selection. A 2(color disparity:High-disparity vs. Low-disparity)×2(opening size)×4(epoch:1-4) within subject design was conducted. The results showed that with the two task operation interacted, different contextual cueing effect were elicited more or less, which suggested that the contextual cueing effect could be modulated effectively by the two task operation. Therefore, it suggested that contextual cueing effect should reflect a dual-stage modulation of attentional guidance and response selection.In conclusion, the present results suggest that predictive configurations should influence both the processes of directing attention and decision processing involving selection. Hence, the contextual cueing effect should reflect a dual-stage modulation of attentional guidance and response selection.