Influence Of Perceptual Cues And Conceptual Information On Fear Generalization

The acquisition of fear is of vital importance to the survival of humans and animals,which can help individuals realize danger and then defend rapidly.In classical fear conditioning,a neutral stimulus that pairs with the aversive event acquires aversive properties.Furthermore,other similar stimulus can also elicit a fear response.It is noteworthy that,unlike animals,people often integrate previous knowledge,using concepts,classification,and reasoning,to generalize learning experience into new but similar stimuli.For instance,a person with injection phobia may be afraid of a series of objects that are perceptually similar to needles,as well as of objects associated with its category,such as hospitals.Despite the dramatic impact of conceptual representations on category-based fear generalization,its neural underpinnings still require elucidation.In this paper,we explored mechanisms that allow for the extension of simple forms of fear generalization to more complex ones,including category-based fear generalization,and the combination of physical form and conceptual meaning.In experiment 1,we explored when perceptual and conceptual cues are incongruent,how the perceptual and conceptual cues are used in fear generalization? The main findings of the study were that perceptual cues elicited larger fear response than conceptual cues in fear conditioning.Furthermore,we found that the incongruent of the perceptual cues and the conceptual information would elicit lager N400 amplitude.Finally,People in safe environment use heuristics,rely on their world knowledge.Dangerous environment,on the other hand,is associated with a more bottom—up,analytic information processing style.In experiment 2,participants completed a category-based fear generalization paradigm while the EEG was recorded.The P2 and N400 ERPs were examined in response to multiple generalization stimuli: inferior typical members of conditioned stimulus(CS)+(TCS+);inferior atypical members of CS+(ATCS+);inferior typical members of CS-(TCS-),and inferior atypical members of CS-(ATCS-).We concluded that the processing of a fear stimulus is a two-stage process: the early perceptual processing stage and a later stage of cognitive processing.The P2 component automatically captures the attention of the salient stimulus,adjusting resource allocations,and thus improving individuals' vigilance levels toavoid danger.On the other hand,the N400 component shows that stimulus processing integrates higher-order cognitive processes,such as semantic networks,generating fear across the whole relevant category.In conclusion,we have four major findings: 1)Conceptual cues and perceptual information can simultaneously promote fear generalization.Fear response generalize more to conceptual stimulus than to the perceptual ones,and the generalization to perceptual stimuli is more likely to extinct;2)The reduction in P600 effect for the dangerous cues as compared to the safe condition could reflect reduced heuristic thinking;3)Stimulus typicality can facilitate the generalization of fear;4)The processing of fear stimuli involves two phases: the early perceptual processing stage and the later stage of cognitive processing.The P2 component indicate that the salient stimulus can automatically capture the attention;whereas the N400 serves as an index of the engagement of higher-order cognitive functions,like semantic network,and enhanced N400 effect was found when the properties of stimulus were incongruent.These studies can provide the following aspects of the clinical implication:(1)Conceptual knowledge systems are involved in the generalization of fear.We can combine simple sensory dimension extinction training and conceptual in extinction training to promote the effect of exposed therapy.(2)Category-based inductive reasoning suggests that typical things are more representative than atypical things.Therefore,using the typical stimuli in extinction may be a better choice.