关键词: 奖赏联结, 自上而下, 注意定向, 注意脱离

Abstract:  The traditional distinction between exogenous and endogenous attentional control has recently been enriched with an additional mode of control, termed as reward history. Recent findings have indicated that previously rewarded stimuli capture more attention than their physical attributes would predict. However, an important question is whether reward-based learning (or value-driven) attentional control is fully automatic or driven by strategic, top-down control? Most researchers have suggested value-driven attentional control is fully automatic, not driven by strategic, top-down control. Although previous studies have examined the phenomenon of value-driven attention capture, few studies have distinguished early attentional orienting and later attentional disengagement in the value-driven attentional control process. Therefore, the present study employed a modified spatial cueing paradigm to disentangle attentional orienting and disengagement and manipulated the goal- relevance of reward distractors to investigate the characteristics of value-driven attentional control. In Experiment 1, rewarded distractors were goal-relevant, and we would expect the prioritized orienting to and the delayed disengagement from rewarded distractors (compared with no-reward distractors) to be evident when both were goal-relevant (i.e., part of the target-set); In Experiment 2, rewarded distractors were not goal-relevant, and we would expect prioritized orienting to and delayed disengagement from rewarded distractors (compared with no-reward distractors) not to be evident when both were not goal-relevant. Forty-eight participants (Experiment 1: 24; Experiment 2: 24) with normal or corrected-to-normal vision were tested. During the training phase, the four positions in the search display were all circles of different colors (such as red, green, blue, cyan, orange, and yellow). Targets were defined as a red or a green circle, exactly one of which was presented on every trial. Inside the target, a white line segment was oriented either vertically or horizontally, and inside each of the nontargets, a white line segment was tilted at 45° to the left or to the right. The feedback display informed participants of the reward earned (+10, +0) on the previous trial, as well as total reward accumulated thus far according to their responses. During the test phase, each trial started with the presentation of the fixation display (900 ms), which was followed immediately by the cue display (100 ms). After the cue display, the fixation display was presented again (100 ms), followed by the target display (100 ms). The target display was followed by a gray screen (until response). The feedback display at test informed participants only whether their response on the previous trial was correct. That is, no reward was provided during the test phase. Results showed that: (1) Across Experiments 1 and 2, we observed the significant main effects of reward. (2) In the test phase in Experiment 1, rewarded distractors were goal-relevant and we observed prioritized orienting to and delayed disengagement from rewarded distractors (compared with no-reward distractors) be evident; in Experiment 2, rewarded distractors were not goal-relevant, and we observed prioritized orienting to and delayed disengagement from rewarded distractors (compared with no-reward distractors) not be evident. The present findings demonstrate that: (1) In the training phase, participants have learned the effect of reward. (2) In the test phase, orienting to and disengagement from rewarded stimuli are modulated by current top-down goals. These findings provide a new perspective on the domain of attention to rewarded stimuli by indicating that even the early orienting of attention to rewarded stimuli is contingent on current top-down goals, suggesting early orienting to rewarded stimuli to be more complex and cognitively involved than previously hypothesized.

Key words: reward association, top-down, attentional orienting, attentional disengagement