Daniel Bjornn and Dr. Michael Larson, Department of Psychology
Conflict adaptation is a neurological process that reflects the adjustment of performance on tasks when conflict is detected on previous trials. Conflict in this instance refers to the simultaneous activation of multiple response options. When conflict is detected, such as on an incongruent trial on Stroop task where the word “red” is written in green ink, there is an increase in the recruitment of cognitive resources to overcome the conflict and make the correct answer. Such increased recruitment of cognitive resources allows for improved performance on incongruent trials that follow other incongruent trials (Gratton, Coles, & Donchin, 1992). The behavioral effects of conflict adaptation can be seen in decreased reaction times in incongruent trials that follow incongruent trials as compared to incongruent trials that follow congruent trials (Kerns et al., 2004).
Generalized anxiety disorder (GAD) is a psychiatric disorder characterized by excessive worry and doubt (American Psychological Association, 2000). Researchers have theorized that deficits in conflict adaptation play a part in the inability to regulate worrisome thoughts (Etkin, Prater, Hoeft, Menon, & Schatzberg, 2010). Conflict adaptation has been studied in individuals with GAD as a means of further understanding the underlying cause for the worry that is common in this disorder. A recent study by Etkin et al. (2010) used an emotional Stroop paradigm that paired happy or fearful pictures of faces with the words “happy” or “fear.” These pairings were either congruent (e.g. happy face with the word “happy” written over the image) or incongruent (e.g. fearful face with the word “happy” written over the image). The results showed that individuals with anxiety disorders display a deficit in conflict adaptation when the participants were required to indicate the emotion displayed on the face. The authors speculated that this deficit is the basis of why they cannot diminish feelings of anxiety.
The present study sought to further research the process of conflict adaptation and how it is related to emotional face processing in individuals with GAD. Rather than using the face/word paradigm that Etkin et al. (2010) used, we sought to study the effects of this process using only emotional faces, thus removing any confounds that written words may present. We hypothesized that individuals with GAD would show significantly increased reaction times and error rates relative to healthy controls on the emotional face Stroop task.
An anxiety group composed of 14 individuals with a diagnosis of GAD was matched to healthy controls according to sex (13 female, 1 male). Participants were interviewed using the Mini International Neuropsychiatric Interview (MINI) to confirm their diagnosis of GAD and then completed questionnaires regarding mental health including the State-Trait Anxiety Inventory, Beck Depression Inventory, and Toronto Alexithymia Scale. An emotional variation of the Stroop task was then administered, which consisted of paired images of human eyes and mouths (see Figure 1 below). Participants responded by indicating whether images of eyes showed anger or happiness while ignoring an incongruent or congruent mouth image. Response times and error rates were compared using a 2-Group (anxiety group, control group) x 2-Previous-trial- congruency x 2-Current-trial-congruency ANOVA.
There was a significant difference between the groups for age (p = .017) and years of education (p = .001) with the anxiety group being older and more educated. Results for the ANOVA of reaction times showed a significant interaction for previous x current trial congruency for both groups F(1,27) = 4.575, p = .042; however, there was no significant interaction or main effect between groups. Overall reaction times for the current trial trended significant between groups, with the anxiety group being slightly faster than the control group, F(1,27) = 4.166, p = .052. ANOVA revealed lower error rates for the anxiety group compared to the control group, F(1,27) = 6.833, p = .015, on current trials but not when considering previous trial congruency.
In conclusion, our results did not support our initial hypothesis. When considering error rates for current trials, the anxiety group outperformed the control group. Reaction times trended toward significant as well. Possible reasons for the lower error rates and reaction times of the anxiety group include 1) the sample was older and more educated, 2) the stimulus itself was not arousing enough for controls, or 3) greater vigilance among the anxiety group. No significant difference was found between the anxiety group and controls when considering previous x current trial congruency. This finding suggests there are no deficits in conflict adaptation in this sample of individuals with GAD. This indicates that conflict adaptation may not be the basis of difficulties in controlling worrisome thoughts in the disorder. Further research is needed in order to confirm this finding and rule out the possible reasons for the results stated above.
- American Psychological Association. (2000). Diagnostic and Statistical Manual of Mental Disorders (4th ed., t.). Washington D. C.: Author.
- Etkin, A., Prater, K. E., Hoeft, F., Menon, V., & Schatzberg, A. (2010). Failure of Anterior Cingulate Activation and Connectivity With the Amygdala During Implicit Regulation of Emotional Processing in Generalized Anxiety Disorder. American Journal of Psychiatry, 167(5), 545–554.
- Gratton, G., Coles, M. G. H., & Donchin, E. (1992). Optimizing the Use of Information : Strategic Control of Activation of Responses, 121(4), 480–506.
- Kerns, J. G., Cohen, J. D., MacDonald, A. W., Cho, R. Y., Stenger, V. A., & Carter, C. S. (2004). Anterior cingulate conflict monitoring and adjustments in control. Science (New York, N.Y.), 303(5660), 1023–6. doi:10.1126/science.1089910