A common symptom of depression is difficulty thinking or concentrating. To rephrase, depressed people often lack the cognitive control required to achieve goals. Researchers at the University of Padua, Italy, sought to determine if the lack of cognitive control in depressed people was present when working on tasks that triggered emotions or if it was present even when tasks were emotionally neutral. Additionally, they were interested in what kinds of tasks resulted in less cognitive control.
Their findings indicate that depression results in difficulties in cognitive control in both emotional and neutral tasks. However, when tasks were emotional, subjects experienced a greater struggle with cognitive control than in neutral tasks. In this condition, managing attention became the primary challenge. Finally, repeated tasks were also challenging for subjects.
Prior research has explored several different aspects related to cognitive control and depression. Findings have indicated that those who are depressed struggle to overcome emotional stimuli to solve problems and modulate attention. If the emotional stimuli were unpleasant, the difficulty increased. The current study intends to understand the complexities of cognitive control during depressive episodes.
The research team obtained a sample of 82 volunteer participants. The sample was 63% female, healthy, and not on any psychotropic medications. Participant depression symptoms were measured by the Beck Depression Inventory-II, a proven reliable, and valid measure.
Subjects were then asked to complete a digital activity categorizing a set of blocks. There were simple and more challenging versions of the activity. Sometimes the simple tasks would repeat themselves, and other times there would be switching between simple and complex tasks.
These tasks were divided into “hot” and “cold” conditions. In the “cold” condition, the blocks had geometric shapes that were to be used to facilitate categorizing. The “hot” condition had blocks with images of faces, two of which were smiling and two who looked distressed. Response times for the categorization tasks under all conditions were collected and analyzed.
Carola Dell’Acqua and colleagues expected to find that as depressive symptoms increased, so would response times in the hot condition indicating challenges with cognitive control. They also expected response times to be longer when exposed to distressed faces than happy ones.
The results were surprising as subjects struggled for cognitive control with tasks both “hot” and “cold.” When tasks were repeated in both conditions, there were increased response times compared to single or switching tasks. Additionally, they did not find a difference in response times between tasks with smiling versus distressed faces.
This was also an unexpected finding with Dell’Acqua and team concluding, “our results are in line with one of the few studies that adopted an emotional (with pleasant and unpleasant trials), rather than a non-emotional version of the same task-switching paradigm and found a selective difficulty in the emotional task-switching paradigm, regardless of the stimulus valence, in individuals with depression.”
Some acknowledged limitations of the study include the unsupervised participants and subjects were provided with clear instructions, but there is no way to know if they followed them. Second, the block task used may be limited in what it can reveal about depressive symptoms and cognitive control.
This study serves to help researchers disentangle the complexities of cognitive control, attention, and depression. The research team made this conclusion: “These findings show the presence of depressive symptoms is associated with a general difficulty to exert cognitive control in both contexts and with a more extended difficulty in even simple attentional processing of affective material.”
The study, “Depressive symptoms and cognitive control: the role of affective interference“, was authored by Carola Dell’Acqua, Simone Messerotti Benvenuti, Antonino Vallesi, Daniela Palomba, and Ettore Ambrosini.