Children Are Less Sensitive To The Informative Value Of Negative Feedback:Evidences From An ERP Study

In the development of children,they need constantly to learn knowledge and accumulate experiences to better adapt to the surrounding environment.And feedback is quite important to their successful behavior.Because feedback not only can inform children the correctness of their current behavior,but also can provide some useful information for their subsequent behavioral improvements.These information can help children quickly modulate their learning strategies,and smoothly achieve a goal.In the study,rule learning paradigms were often used to research this two aspects of feedback,valence and informative value(Mies et al.,2011;Tricomi & Fiez,2012).The valence means the correctness of feedback,and informative value means the specific guidance of one’s subsequent performances.Studies about the valence of feedback lasted for many years,and we have learnt about the neural mechanism under it very well.But studies about the informative value of feedback are few,and the differences between adults and children are still unclear.Some studies investigated the brain mechanism on it,but most of the tasks did not effectively distinguished the informative value from the valence of feedback.To better solve this problem,we designed a new task based on the Wisconsin Card Sorting Test,which is called rule induction task(RIT).Through RIT task,we can further make some investigations of the informative value of feedback.In the experiment 1,we used Event-related Potentials(ERPs)investigated the components related to the valence and informative value of feedback in adults.Two conditions,the RIT and the control were designed.In both conditions,children were asked to find candies from the testing stimuli.In the RIT,the left target stimulus was a candy and two of the four testing stimuli were candies,while the other two were not.In each trial,all candies(i.e.,one target and two testing stimuli)shared one common attribute.For example,all candies have horizontal stripes.There were three perceptual dimensions,and subjects did not know which perceptual dimension was associated with the identification of a candy.After trial and error,they could find the rule regarding the category to which the candies belonged.The participant’s task was to find the two candies amongst the testing stimuli by pressing the corresponding number below them.In the RIT,participants’ first choice was based on a guess.However,children could use the informative value of the first feedback to decide which testing stimuli should be selected the second time.On each choice,a check mark would appear on the top of the selected one if it is a candy;if not,a fork mark would appear.In the control condition,the left stimulus was also a candy,but there was only one candy amongst the testing stimuli.Participants either luckily found the candy(positive feedback)or failed(negative feedback).Therefore,in the control condition,there was no informative value of feedback and instead only valence was present.By contrasting two kinds of feedbacks above,we can separate informative value from the valence of feedback.ERP results indicated that(1)the effects of valence and informative value were processed in a wide time window,particularly in the N2 and P3 components;(2)the processing of informative value of feedback was not influenced by valence.In the experiment 2,we further investigated the electrophysiological differences between children and adults when they confronted the two aspects of feedback.Because of the high time resolution of ERP,we adopt the same task which was used in experiment 1.Event-related potentials showed that(1)the encoding process of the informative value of negative feedback began later for children than for adults,and the condition effect for children was found until N2 component;(2)a clear P300 was observed for adults;for children,however,P300 was absent in the frontal region;(3)children processed the informative value of feedback chiefly in the left sites during the P300 time window,whereas adults did not show this laterality.In total,these results suggested that children were less sensitive to the informative value of negative feedback possibly because of the immature brain and poor cognitive control ability.