Our brain is remarkably flexible in producing different reactions to supposedly comparable situations. The same sensory information can lead to different decisions depending on the behavioral context. One example of this is a penalty kick in soccer: a player can either choose the empty corner of the goal as the target or aim directly at the goalkeeper in the hope that he will jump aside. Both decisions are based on the same perception of the goalkeeper's position, but lead to completely different actions. Neuroscientists at the German Primate Center (DPZ) - Leibniz Institute for Primate Research in Göttingen have investigated how the brain implements this type of flexibility. Their results show that, depending on the requirements, our brain either reuses known neural pathways or develops new patterns to select movements depending on the context. Thus, goal-directed behavior and cognitive flexibility can be achieved in different ways, depending on the circumstance that made the flexible adaptation of behavior necessary. The findings help to understand why it is more difficult to adapt to some new situations than to others - whether in social interactions or motor tasks (Nature Communications).
The researchers trained rhesus monkeys to plan arm movements and recorded the activity of neurons in the brain that are involved in planning these movements. The monkeys performed the task in two different contexts. In the first context, they had to use a learned rule to decide whether they should point at the target displayed on the screen ("goalkeeper") or choose the opposite side of the screen ("empty corner"). In the second context, the monkeys had to adapt to an altered sensory environment by performing the tasks under mirror-inverted viewing conditions. Here, too, a target shown on one side was linked to a movement to the opposite side.
The study showed that the brain works in different ways in the two situations. In the first context, which is based on learned rules, the brain drew on existing neural patterns. It used the pre-existing networks to plan the movement without making fundamental changes to the neural connections. In the second context, where the sensory environment had changed, the brain had to develop new neural patterns to accomplish the task. The flexibility of the brain to interpret and respond to the same sensory information differently depending on the situation is therefore achieved in different ways.
"Flexibly associating different behaviors with a given situation is a core competence of our brain," explains Alexander Gail, head of the Sensorimotor Research Group and the study. "Sometimes this requires a complex restructuring of neuronal circuits, but often so-called cognitive control is sufficient, in which - as our new findings suggest - neuronal patterns already known to the brain are reused. We assume that this mechanism also comes into play when we make decisions in changing social contexts, which may be more competitive or more collaborative, for example - but we have yet to prove this."
