| When stimuli are associated with reward outcome,their visual features will acquire high attentional priority such that stimuli possessing those features can involuntarily capture attention.This phenomenon is called value-driven attentional capture.Although the effect of the reward-learning has been observed in a range of situations in previous studies,the mechanism underlying the association between stimulus features and reward during the learning phase remains unclear.Most previous studies associated a target-defining feature with reward in the learning phase.The value-driven attentional capture observed with features not defining the target and it's mechanism remains unclear.Most previous studies used a single feature to predict reward in the learning phase,but when integration information(color and location;color and scene)were used to predict reward in the learning phase,the attention capture model was unknown;Whether the value-driven attentional capture by reward-associated stimuli results from spatial-shift of attention or from non-spatial form of distration remains controversial and should be further investigated.The present study explored the above mentioned problems by designing different experimental conditions,and using a training-testing paradigm.Three studies including seven experiments were carried out.In study 1,we explored the role of feature and spatial location in value-driven attentional capture using a training-testing paradigm.In study 2,we used the same paradigm as studyl to test the role of feature and spatial scene in value-driven attentional capture.In study 3,we explored the role of task-irrelevant color feature in value-driven attentional capture.The more detailed contents and main findings were shown as follows.In study 1,three experiments were included.Experiment 1 was designed to test whether color stimuli presented in the specific spatial location can capture attention via reward-based learning or not.In the training phase,red targets appeared at four of eight possible stimulus positions;For example,correct responses were accompanied by a higher reward when the targets appeared at the upper left or lower left position and accompanied by a lower reward when the targets appeared at the upper right or lower right positions.The other four positions were neutral locations,and no target appeared at those positions.In the test phase,the red stimulus was presented as distractor.It was found that when the red stimulus was presented at the position associated with higher-reward or at a neutral position between the two high-reward positions,attention can be captured.However,when it was presented at the position associated with lower-reward or other neutral positions,attention cannot be captured.Experiment 2 was designed to test whether color stimuli presented in the specific spatial location can capture attention via reward-based learning or not and underlying mechanism.In the training phase,red targets appeared at four of ten possible stimulus positions,correct responses were accompanied by a higher reward when the targets appeared at the two adjacent positions and accompanied by a lower reward when the targets appeared at the other two adjacent positions.The other six positions were neutral locations,and no target appeared at those positions.In the testing phase,the red stimulus was presented as distractor.It was found that when the red stimulus was presented at the positions associated only with higher-reward,attention can be captured.However,when it was presented at the positions associated with lower-reward or other neutral positions,attention can not be captured.Experiment 3 was designed to test the interaction effects of color feature and spatial location in value-driven attentional capture.In the training phase,for example,correct responses were accompanied by higher rewards when red targets appeared at the upper left or lower left position,and were accompanied by lower rewards when green targets appeared at the upper right or lower right position.In the test phase,red or green stimuli were presented as distractors.The result showed when a higher-reward color stimulus appeared at the position associated with higher-reward or at a neutral position between the two high reward positions,attention could be captured.However,when it appeared at a position associated with lower-reward or other neutral positions,attention cannot be captured;When a lower-reward color stimulus appear at a position associated with higher-reward or other positions,attention cannot be captured.In study 2,two experiments were included.Experiment 4 was designed to test whether color stimuli presented in the specific scene can capture attention via reward-based learning or not.In the training phase,correct responses were accompanied by a higher reward when the red color targets appeared at one scene and accompanied by a lower reward when the targets appeared at the other scene.In the test phase,the red stimulus was presented as distractor and in valuable scenes and neutral scene.It was found that when the red stimulus was presented at the scene with higher-reward,attention can be captured.However,when it was presented at the scene with lower-reward or neutral scene,attention cannot be captured.Experiment 5 was designed to test the interaction effects of color feature and spatial scene in value-driven attentional capture.In the training phase,for example,correct response was accompanied by higher reward when red target appeared in one scene,and was accompanied by lower reward when green target appeared in another scene,In the test phase,red or green stimuli were presented as distractors.The result showed when a higher-reward color stimulus was presented in all scenes,attention could be captured.In study 3,two experiments were included to tested whether task-irrelevant features induce value-driven attentional capture even in the test phase with no reward.Experiment 6 was designed to test the effect of color feature as a salient distractor in value-driven attentional capture.In the training phase,we used a flanker task during reward learning to create color-reward associations,and then tested the effect of color during visual search in test phase.Reward learning with non-spatial uncertainty in the flanker task induced,even when reward signaling color was associated with distractor.Experiment 7 was designed to test the effect of color feature as no salient distractor in value-driven attentional capture.The design,and procedure were identical to Experiment 1,with one exception.In the test phase,the target was presented as no-salient distractor.Reward learning with non-spatial uncertainty in the flanker task induced,even when reward signaling color was presented as no-salient distractor.To summarize,following conclusions were made.(1)Reward-prediction information were sufficient and necessary for value-driven attentional capture.Reward-prediction information included not only task-related such as color feature and location of target,but also task-irrelated such as scene and color feature of distration stimulate.(2)The effect of attentional capture by specific spatial location associated with higher-reward showed some degree of generalization:When the valued stimulus was presented at the position associated with higher-reward or at a neutral position between the two high-reward positions,attention can be captured.The generalization of value-driven attentional capture was attributed to the global effect rather than diffusing effect.(3)When color feature and spatial location were combined to predict reward,the participant's study integration information(color and location)in the training phase cannot be generalized to partial features(e.g.independent color feature).(4)When color feature and scene were combined to predict reward,the participant learned independent information(color and scene)respectively in the training phase,color feature would acquire attention priority,.but sence had not effec on value-driven attentional capture.(5)Most of the subjects could aware explicitly information-reward assocaition,value learn was explicit,rather than implicit.(6)RT cost caused by a reward-associated distracter was resulted from non-specific filtering cost,rather than spatial shift of reward-driven attentional... |
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