Physiological evaluation of psychological treatments for anxiety

Does anxiety explain why math-anxious people underperform in math?

Math-anxious people consistently underperform in math. The most widely accepted explanation for why this underperformance occurs is that math-anxious people experience heightened anxiety when faced with math, and this in-the-moment anxiety interferes with performance. Surprisingly, this explanation has not been tested directly. Here, using both self-report and physiological indices of anxiety, we directly test how much in-the-moment anxiety explains math-anxious underperformance. Results indicate that in-the-moment anxiety indeed explains why math-anxious people underperform-but only partially, suggesting a need to seriously consider alternative mechanisms. Results also showed that while some highly math-anxious individuals-those with high levels of heart rate variability-experienced less in-the-moment anxiety, they nevertheless performed no better at math. For these individuals, math-anxious underperformance must occur for reasons unrelated to in-the-moment anxiety. More broadly, our findings point to substantial individual heterogeneity in the mechanisms underlying math-anxious underperformance. Accounting for this mechanistic heterogeneity may prove vital for optimally boosting math performance in math-anxious individuals.

The psychophysiology of generalized anxiety disorder: 2. Effects of applied relaxation

Muscle relaxation therapy assumes that generalized anxiety disorder (GAD) patients lack the ability to relax but can learn this in therapy. We tested this by randomizing 49 GAD patients to 12 weeks of Applied Relaxation (AR) or waiting. Before, during, and after treatment participants underwent relaxation tests. Before treatment, GAD patients were more worried than healthy controls (n=21) and had higher heart rates and lower end-tidal pCO2, but not higher muscle tension (A. Conrad, L. Isaac, & W.T. Roth, 2008). AR resulted in greater symptomatic improvement than waiting. However, 28% of the AR group dropped out of treatment and some patients relapsed at the 6-week follow-up. There was little evidence that AR participants learned to relax in therapy or that a reduction in anxiety was associated with a decrease in activation. We conclude that the clinical effects of AR in improving GAD symptoms are moderate at most and cannot be attributed to reducing muscle tension or autonomic activation.