Value Effect Influence Attentional Capture In PTSD Adolescents

In the research field of attentional capture, top-down and bottom-up mechanism mechanism is two kinds of common model.But recently studies found that the association between reward and stimuli can also capture attention, which is called value-driven attentional capture. It is a kind of new mechanism that is different from the traditional attentional capture mechanisms. The value driven attentional capture mechanism is independent of stimulus driven and goal driven attentional capture mechanism, but it also has the connection with two mechanisms.The theoretical basis of this mechanism is the ability of orienting to reward-associated objects and avoiding objects unlikely to be beneficial,individuals will try to maximize the reward and minimize the loss in the environment. The new mechanism is reflected through the value effect, the value effect refers to give some value to specific stimuli such as money reward, so that the subject have corresponding changes to specific stimuli..Studies have indicated that PTSD patients may be associated with cognitive impairment, such as attention deficit control, and executive control deficits, and they are often associated with impairment of the reward function and abnormalities in the dopamine system. And physical and mental development is not mature in adolescent, it is susceptible of PTSD.The aim of this study was to explore how the value effect influence attentional capture of the behavior and nerve electrophysiology in PTSD adolescents. Experiment 1 is a behavior experiments to explore the characteristics of attentional capture in PTSD adolescents,31 subjects are screened through PTSD Checklist-Civilian Version(PCL-C) who experienced Wenchuan earthquake, the experimental paradigm is the combination of value training and visual search,the experiments are divided into value training phase and visual search phase.Results showed that:(1) In the value training phase,high reward stimuli were significantly faster than low reward stimuli, indicating that the associations between stimuli and reward outcomes formed, appeared the value effect;(2) In the visual search phase,the high reward distractor condition of testing phase is significantly slower than the low reward and without interference condition,indicating the associations in the visual search phase take effect, value driven attentional capture formed.And PTSD adolescence and the control group has no significant difference,showed that both two groups had value driven attentional capture.Based on the experiment 1, experiment 2 use the EEG/ERPs technology to explore value effect influence the attentional capture electrophysio logical rules in PTSD adolescents.19 subjects were selected by the same criteria as experiment 1,the experimental paradigm and procedure is the same as tle experiment 1.Results showed that:(1)In the value training phase,high and low value conditions all elicited a N2pc,but the amplitude of high value is bigger;(2) In the visual search phase,the high reward distractor condition elicited a greater N2pc amplitude, and the same as the control group, PTSD group also has a signicant difference between the three distractor conditions of N2pc amplitude, but not as good as the control group the difference is more obvious. The results showed that the value effect also influencethe changes of EEG Waves,two groups of subjects all acted the attentional priority to high reward distractors.The whole study showed that the associations between stimuli and reward outcomes formed in training phase have a great influence of attentional selection,high reward distractor attract more attention,and due to the sensitivity of teenagers, the avoidance tendency of PTSD patients and personality traits, PTSD and control group of adolescence all emerge the value driven attentional capture.