When it comes to making preference-based decisions, such as what to order on a menu or which color of shirt to purchase, some people come across as being much more indecisive than others. According to a new study by researchers at the University of Zurich, this indecisiveness may be caused by a disruption in communication between two separate regions of the brain.
Preference decisions (also referred to as value decisions) are different from sensory or perceptual-based choices, which call for a more straightforward or logical assessment of whatever you’re deciding between. For instance, deciding whether a car is blue or red is a perceptual/sensory decision (it’s either factually blue or red), whereas deciding whether to purchase the same car in either red or blue is more of a preference-based choice.
The goal of the study was to find out why some people have a harder time making preference-based decisions while others seem to know exactly what they always want.
Volunteers were asked to look at images of food and decide which one they would rather eat (preference decision), as well as which image had more of the color black in it (sensory decision). At the same time, researchers stimulated the brain using a non-invasive technique called “transcranial alternating current stimulation,” which could safely manipulate the flow of information between the prefrontal cortex region of the brain and the parietal cortex.
The findings showed that when there was less flow of communication between the prefrontal and parietal cortexes, it resulted in more unstable preference-based decision making. However, the participants’ ability to make sensory-based decisions was not impacted at all. Interestingly, the researchers found that they could not create the opposite effect—intensifying the flow of information between the cortexes didn’t necessarily make participants’ preferential decisions any more stable.
According to the lead author of the study, “Communication between the two brain regions is only relevant if we have to decide whether we like something and not when we make decisions based on objective facts.”
The findings from this study have been published in a recent issue of Nature Communications.
Sources for Today’s Article:
Polonía, R., et al., “The precision of value-based choices depends causally on fronto-parietal phase coupling,” Nature Communications 2015, doi: 10.1038/ncomms9090, http://www.nature.com/ncomms/2015/150820/ncomms9090/full/ncomms9090.html.
Paddock, C., “Value decisions rely on communication between two brain regions, study shows,” Medical News Today web site, August 24, 2015; http://www.medicalnewstoday.com/articles/298418.php.