Contextual Cueing Accelerated And Enhanced By Monetary Reward:Evidence From Event-related Brain Potentials

Contextual cueing(CC)effect refers to the phenomenon that search times to targets among consistent spatial contexts(repeated configuration)across repetitions are faster compared with where the spatial contexts(novel configuration)vary.This is a type of implicit learning: CC occurs because the implicitly learned association between the target location and the configuration constrains what to expect and guides where to attend and look.That is,the global visual context may implicitly guide spatial attention directly towards the location of the target embedded among the distractors stimuli.We focus on the idea that whether incidental learned context knowledge could be affected by reward.Stimulus preceding negativity(SPN)is a slow potential which has been proposed reflecting affective/motivational processing,and usually starts a few seconds before feedback onset and exhibits peak amplitudes just before the stimulus presentation.With the SPN,this study examines this idea using the standard contextual cueing paradigm by introducing a reward feedback after participants' response to the search displays to inform them whether they get a reward or not in this trial.In experiment 1,half of repeated and novel configurations are always followed by reward feedbacks(reward condition)and the rest repeated and novel configurations always trigger nonreward feedbacks(nonreward condition),the amplitudes of SPN in reward condition will be compared with that in nonreward condition.Note that the participants are never informed about this setting.Behavior results show that RTs to the repeated configurations under reward condition is fastest.Also,contextual cueing effect emerge faster in reward condition than nonreward condition.Meanwhile,brain data demonstrate that contexts followed by reward feedback obtain larger SPN amplitude at frontal lobe and parietal lobe than nonreward contexts.These results demonstrate that reward modulates CC.Experiment uses an analogous design in experiment 1,except that the reward condition were divided into high reward condition and low reward condition,to explore further that whether the reward magnitude will affect CC.Neither RTs nor SPNs amplitude of reward condition(high reward and low reward)show statistically significant difference,demonstrating that CC is insensitive to reward magnitude.Interestingly,the faster RT and larger SPN of low reward condition compared with nonreward condition in novel configuration indicates that reward may also modulate target location probability effect in this paragram.In sum,both behavioral and electrophysiological results suggest that participants learned the associations between different repeated configurations and reward in present study,and,furthermore,speed up their response to reward repeated configurations,indicating that reward could modulate contextual cueing effect.