People with social anxiety disorder, who have an extreme fear of social objects or situations, seem primed to experience negative emotions in situations that would have no impact on others. For example, in social anxiety disorder, individuals may fear perfectly ordinary situations, even one as seemingly innocuous as eating in public. To qualify as having social anxiety disorder, these fears must be persistent and extreme, and the individual must suffer impairment in daily life while recognizing that the fears are unreasonable. At the heart of the disorder are people’s belief that they will embarrass or humiliate themselves. To investigate the role of learning in social anxiety disorder, National Institute of Mental Health neuroscientist Karina Blair and colleagues (2016) recently compared brain scans of individuals with and without the disorder in response to a series of slides programmed to lead to negative, positive, and neutral reactions.
The basic rationale behind the study was that people acquire their fears early in life, by observing the reactions of their caregivers to situations, particularly ones in which they are unsure of how to act. In social anxiety disorder, these reactions often involve new situations. Very young children can sense the fears of their caregivers quite readily, even before they understand language. Consider what happens when a mother brings her infant son to a new physician’s office. The infant can sense that the mother is anxious when she holds him especially tightly and even, perhaps, by sensing her more rapid breathing and beating of her heart. As children get older, they are capable of noticing more signs of how their parents are reacting to new situations and objects on top of what they’ve already learned over the years. They can understand what their parents say to them but, just as importantly, become able to gauge their nonverbal reactions as well.
The NIMH team used an innovative experimental method to observe how people with social anxiety disorder would respond not directly to a phobia-producing (i.e. novel) stimulus, but to a person showing a fearful response to a novel object. In their experiment, participants saw animated slides in which a male or female adult showed one of four reactions to an object designed uniquely for the study (e.g. something looking like a caterpillar with a star instead of a head). The 4 reactions included fear, anger, no response, and laughter. For the experiment’s first phase, participants saw the objects paired with the face of the person looking at the object expressing one of those 4 reactions. In the second phase, participants saw the objects without the faces. If observational learning indeed took place, the participants would respond similarly to the objects alone without the faces being present. Since all of this was happening in an fMRI scanner, the researchers could compare the brain activation patterns in phase 1 with the patterns shown by the participants in phase 2.
It’s known that the amygdala, a subcortical structure located in the limbic system, is the part of the brain that becomes activated in fear-related situations, including those in which other people display fear. As stated by the authors, “the amygdala is critical for learning the valence of novel objects from the emotional expressions of others”. Therefore, Blair and her team investigated the response of the amygdala, comparing people with social anxiety disorder and their age-matched controls. Another relevant brain region is in a part of the cortex involved in processing information relevant to the self. When you decide, for example, that something involves you- whether it be a threatening situation or just a social interaction in general- this part of your brain becomes engaged as well.
Participants weren’t aware of the study’s focus, as their task was to indicate, in phase 1, whether the face they were viewing was male or female. In phase 2, participants indicated whether they wanted to approach or wanted to avoid the novel object. Again, none of the participants knew the actual purpose of the experiment.
The findings revealed that, as hypothesized, the participants with social anxiety disorder showed increased activation of the amygdala in phase 2 when the objects had been associated, during phase 1, with fear. They also showed a slight, not non-significant, tendency to wish to avoid the object associated with fear compared to their non-socially anxious matched controls. Furthermore, there was a positive association between the severity of their social anxiety disorder symptoms and their amygdala’s activation in the presence of the conditioned-fear objects.
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