Difficult decisions are part and parcel of life. From simply choosing between items on a menu to more difficult choices that relate to life partners, careers and education, decisions rule us and also define us. Decisions can be of two types: preference based decisions that are – as the name suggests – about what you prefer, and sensory decisions based on your senses – what looks bigger, what smells worse, what feels better, etc. As you can imagine, sensory decisions are less prone to indecisiveness.
A team headed by Professor Christian Ruff at the University of Zurich set about finding out why some people are sure of what they like and want, while others are more uncertain of their preferences.
The participants in the study just had to make preference-based or purely-sensory decisions about food. They were unaware that they were being stimulated.
For the study, the researchers used a brain stimulation technique called transcranial alternating current stimulation. This non-invasive technique helped them generate coordinated undulations in the activity of certain brain regions.
Using this technique, the researchers kept changing the level of data flow amid the prefrontal cortex and the parietal cortex of the brain.
The researchers observed that when the information flow between the two brain regions was disrupted, the subjects (both male and female) were more indecisive and the preference-based decisions were less stable.
However, they did not notice any change in the strictly-sensory decisions.
From this it was gathered that the communication between the two brain regions is pertinent only when we are making a decision about whether we like something and not when we make choices regarding objective facts.
When the researchers tried to see if intensifying the information flow would make the decisions more stable, it did not work. The researchers feel that this could be because the study participants were young, healthy test subjects with highly developed decision-making skills.
They surmise that in patients with cognitive disorders, who suffer from a high degree of indecisiveness, intensifying the information flow would make the decisions more stable. If that is indeed the case, their technique could be used for therapeutic measures in the future. Of course, more studies need to be done to get to that stage.