What ethologically based models have taught us about the neural systems underlying fear and anxiety

Classical Pavlovian fear conditioning to painful stimuli has provided the generally accepted view of a core system centered in the central amygdala to organize fear responses. Ethologically based models using other sources of threat likely to be expected in a natural environment, such as predators or aggressive dominant conspecifics, have challenged this concept of a unitary core circuit for fear processing. We discuss here what the ethologically based models have told us about the neural systems organizing fear responses. We explored the concept that parallel paths process different classes of threats, and that these different paths influence distinct regions in the periaqueductal gray - a critical element for the organization of all kinds of fear responses. Despite this parallel processing of different kinds of threats, we have discussed an interesting emerging view that common cortical-hippocampal-amygdalar paths seem to be engaged in fear conditioning to painful stimuli, to predators and, perhaps, to aggressive dominant conspecifics as well. Overall, the aim of this review is to bring into focus a more global and comprehensive view of the systems organizing fear responses.

The effects of tourniquet pain on attention bias towards pain-related words and its gender difference / 中华行为医学与脑科学杂志

ObjectiveTo investigate the effect and gender differences of experimental moderate pain on attentional bias towards pain-related words.MethodsWith the tourniquet around the left upper limb,32 healthy college students were asked to perform two dot-probe tasks including five kinds of pain-related words,one task with the tourniquet deflating and the other task with the tourniquet inflating to 200 mm Hg pressure.The reaction time (RT) and the error rate of recognition task were recorded.The pain intensity and distress were recorded too.Results ( 1 ) Compared with no pain condition ( RT of affective and social-threat words were (507 ± 78 ) ms,(504 ±89 )ms respectively),the react time was shorter in female in the condition of tourniquet pain,particularly for affective and social-threat words (the RT were (464 ± 79 )ms,(465 ± 72 )ms respectively,F ( 1,4) =19.157,P ＜0.01 ),but not in male.( 2 ) In condition of no pain,the reaction time of male ( (456 ± 59) ms ) was shorter than that of female (504 ± 79ms).However,in the condition of pain,the significant main effect was not found.ConclusionThe reacting time of female was shorter in condition of moderate tourniquet pain,which imply that female showed significant attentional bias towards affective and social-threat words.