How do expectations control our emotions - and what does attention have to do with it?

Our moods and feelings are closely linked to our expectations. When we look forward to something, it lifts our mood and we perceive our surroundings more positively. Conversely, worries and fears can weigh us down and cause us to focus on negative things.

It is therefore no surprise that significant placebo effects often occur when practitioners interfere with patients' emotional processing. In antidepressant treatments, for example, placebo effects can account for up to 80 percent of the effectiveness. It is therefore important to understand these effects in more detail.

Pain and affect systems are closely linked in the brain

This is what we are working on in Project A06. During the first funding phase of our Collaborative Research Center, we were able to identify important parallels to the effect of expectation effects on pain. This is not surprising, as the pain system and the so-called affect system, in which emotions are processed, are closely linked in the brain.

This applies, for example, to expectation effects caused by verbal or written explanations. In both systems, these effects are closely related to cognitive performance: if a doctor explains the advantages of a new therapy to their patient, the patient must pay a certain amount of attention in order to follow the explanation and be able to recall it later. The frontal lobe, which is responsible for attention and control processes, plays an important role in this.

Those who are less able to pay attention may benefit less from positive expectation effects.

This correlation can become a problem when a person's mental capacity is limited. One reason for this may be aging processes or depressive phases of illness, during which patients often have reduced cognitive resources. As a result, affected individuals may benefit less from the positive expectation effects that arise from verbal instruction.

That is why, in Project A06, we are now focusing on understanding whether and how positive expectations can be generated and take effect independently of complex cognitive resources—and how they can be measured in this case. We are conducting experiments with healthy volunteers, carrying out behavioral studies, and collecting data from functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) to analyze the effects at the neurobiological level. In addition, we are conducting a clinical study to investigate how patients with depression can benefit from positive expectations in their further treatment.