Emotion and attention regulation in arachnophobic subjects: an fMRI study

Emotions are adaptively useful for our survival, but when they are not appropriate to the situation they can become disadvantageous. Fear has the primary function to motivate escape from dangerous stimuli and to guide selfprotective behaviour, but if it is too strong it can disturb the normal physiological and psychological functioning of individuals. In our everyday life we often have to control our emotions, and we use different automatic and controlled strategies to either up- or down-regulate our reactions. Within the current research we studied individuals who suffer from arachnophobia. This disease is a clear example of how an excessive and unreasonable fear toward a phobic stimulus could have a negative influence on an individual’s life. In the last decades several studies have shown that phobic subjects have a deficit in the recruitment of those brain regions that are linked with both automatic and controlled emotion regulation strategies, but some results are still contradictory and the mechanisms that underlie the control of emotions in phobic subjects remain largely unclear. In order to better understand this topic, we asked arachnophobic and control subjects to down-regulate or keep their emotional reactions, applying both automatic (attentional deployment) and voluntary (reappraisal) control strategies. The manipulation of the automatic strategy consisted in driving subject’s visual attention toward or away from the threatening stimulus, while the voluntary strategy was manipulated asking the subjects to down-regulate their emotions or keep them unaltered during the viewing of spiders. Regarding the manipulation of the automatic control of emotional reaction, we found that this kind of regulation had a greater impact on arachnophobic subjects compared to controls. This was displayed by the activation of the ACC, one important region involved in the automatic control of emotions. As for the controlled regulation of emotional reaction, we didn’t find any significant difference between the two groups in the dorsal prefrontal regions that normally are linked to the controlled regulation of emotions. Moreover, we found that the presentation order of the images gives rise to different neural reactions. In the FS condition (alterting) there was stronger recruitment of the amygdala and the ACC than in the SF condition (relief) for phobic subjects, suggesting that they experienced an increase of anxiety. In the opposite contrast instead, there was stronger recruitment of the precuneus in the SF condition (relief) than in the FS condition (alerting). A better understanding of the neural correlates linked to these deficits of emotion regulation could be useful from a therapeutical point of view, helping phobic subjects to improve the control of their reactions and to manage their fears