Why Are Some People So Indecisive?

· May 29, 2016

When communication between two regions of the brain is interrupted, we become more indecisive when faced with decisions of value and preference.

However, the interruption of this communication does not affect the quality of objective or sensory decisions. This could explain why some people are so indecisive, and others are not.

A study published recently in Nature Communications explains why the strength of the communication between the different regions of the brain determines the degree of decisiveness with which decisions of value are made.

In the study, lead scientist Christian Ruff, professor of neuro-economics at the University of Zurich in Switzerland, and his team found that the intensity of the communication between the different regions of the brain determines how value-based decisions, or deciding what we like or do not like, are made. 

Different attitudes for different decisions 

Value-based decisions concerning preference are different than decisions based on information we receive through our senses: what we see, hear, smell, taste, or touch. Examples of value-based decisions would be choosing a new car, a new dress, or what to order from a menu. We must decide what we like best, and later we may question whether or not it was the right choice.

Decisions based on sensorial questions are less prone to indecision, given that they require a more direct evaluation of the properties being considered.

big question mark indecisive

Findings can explain why some people are more indecisive than others 

Why is it that some people always seem to know exactly what they want, while others are never sure? Professor Ruff and his colleagues wanted to find out why some people seem to be much more decisive with their personal preferences, while others seem to be more indecisive and unsure of what they want.

The researchers discovered that the precision and stability of these decisions of preference are not based only on the level of activity in different areas of the brainbut rather in the intensity of the communication between two specific regions of the brain.

The two regions are the prefrontal cortex, located just below the forehead, and the parietal cortex, located just above both ears. Both of these parts of the brain participate in the forming and representation of our preferences, spacial orientation, and planning our actions.

Decisions of value are based on the communication between two regions of the brain

To conduct the study, the team invited volunteers to make two different types of decisions about food: one preferential, and the other objective and sensorial. While making these decisions, the volunteers were subject to a type of non-invasive brain stimulation, a system of transcranial electric stimulation.

This system works by alternating stimulation. During the process, the brain is sent alternating currents of electricity through the cranium in order to generate coordinated patterns of activity in specific parts of the brain.

While this was happening, the volunteers were shown pictures of different foods. At the end they were asked what food they would prefer to eat (testing decisions based on preference). They were also asked sensorial questions about the pictures, for example comparing the how much of the color black there was in one picture compared to another (testing decisions based on sensory and objective information).

Using this stimulation technique, the researchers either intensified or reduced the flow of information between the prefrontal cortex and the parietal cortex when they asked the volunteers to make decisions.

human brain indecisive

Professor Ruff explains his findings: “We discovered that decisions based on preference were less stable if the flow of information was interrupted between the two areas of the brain. Our test subjects were, overall, more indecisive. For purely sensorial decisions, however, this effect was not present.” 

Ruff and his team conclude that it seems that “the communication between these two areas of the brain is only relevant if we have to decide whether or not we like something and it is not relevant when we make decisions based on objective facts.” 

The team also discovered that the nature of the decision itself does not become more stable or certain by intensifying the flow of information between the two regions of the brain. This could be due to the fact that the volunteer test subjects were all young and healthy, with highly developed decision-making skills

Because of this, the researchers note that it is necessary to conduct further studies in order to verify whether or not this technique could be useful for therapeutic purposes. It could be helpful, for example, in the treatment of patients with a high tendency of impulsivity or indecision due to a severe mental disorder or brain injury.