it is prima facie implausible that the actual value of that parameter should just happen to be at one of these rare local optima. Neural activity A study found that erroneous status quo rejections have a greater neural impact than erroneous status quo acceptances. This asymmetry in the genesis of regret might drive the status quo bias on subsequent decisions. A study was done using a visual detection task in which subjects tended to favour the default when making difficult, but not easy, decisions. This bias was suboptimal in that more errors were made when the default was accepted. A selective increase in sub-thalamic nucleus (STN) activity was found when the status quo was rejected in the face of heightened decision difficulty. Analysis of effective connectivity showed that inferior frontal cortex, a region more active for difficult decisions, exerted an enhanced modulatory influence on the STN during switches away from the status quo. Research by University College London scientists that examines the neural pathways involved in 'status quo bias' in the human brain and found that the more difficult the decision we face, the more likely we are not to act. The study, published in Proceedings of the National Academy of Sciences (PNAS), looked at the decision-making of participants taking part in a tennis 'line judgement' game while their brains were scanned using functional MRI (fMRI). The 16 study participants were asked to look at a cross between two tramlines on a screen while holding down a 'default' key. They then saw a ball land in the court and had to make a decision as to whether it was in or out. On each trial, the computer signalled which was the current default option – 'in' or 'out'. The participants continued to hold down the key to accept the default and had to release it and change to another key to reject the default. The results showed a consistent bias towards the default, which led to errors. As the task became more difficult, the bias became even more pronounced. The fMRI scans showed that a region of the brain known as the sub-thalamic nucleus (STN) was more active in the cases when the default was rejected. Also, greater flow of information was seen from a separate region sensitive to difficulty (the prefrontal cortex) to the STN. This indicates that the STN plays a key role in overcoming status quo bias