| Popis: |
Neural degeneracy refers to the idea that distinct neural systems are capable of performing the same functions (Noppeney, Friston, & Price, 2004). Consistent with neural degeneracy, the Theory of Constructed Emotion (TCE) suggests that emotions and other mental states arise from combinations of the brain’s domain-general intrinsic networks such as the default mode network, salience network, and frontoparietal control network (Clark-Polner, Johnson, & Barrett, 2017). A key prediction of degeneracy and the TCE is that the same emotion can emerge from distinct patterns of connectivity across time or across individuals (Barrett, 2017). This project specifically investigates the principle of neural degeneracy in emotion for the first time using a data-driven model building algorithm with unsupervised classification (S-GIMME; Gates, Lane, Varangis, Giovanello, & Guskiewicz, 2017) to quantify distinct patterns of between-network connectivity during self-generated experiences of anxiety and anger. Twenty-four subjects underwent an fMRI experiment in which they listened to unpleasant music and self-generated experiences of anxiety and anger. The hypotheses of this experiment were tested in four consecutive analysis steps. The first analysis step revealed that the S-GIMME procedure could roughly reproduce the experimental conditions in the present experiment by subgrouping individuals based on patterns of connectivity that differentiated anger and anxiety. The second analysis step revealed that this variation could be further subdivided into degenerate neural pathways within each emotion category. The third analysis step showed that subgroups revealed during the anger and anxiety conditions are distinct from those found during a task-positive control condition in which participants listened to neutral music but did not generate an emotional experience. Finally, the fourth analysis step provided a more stringent test of the degeneracy hypothesis by showing that distinct patterns of connectivity revealed in the previous analyses are not the result of stable individual differences that would also be present at rest. Taken together, these analyses show that different patterns of connectivity are associated with the experience of the same emotion. |
