Your brain’s nucleus accumbens gets more active when a reward is in the offing Our brains seem better at predictions than we are. A part of our brain becomes active when it knows something will be successfully crowdfunded, even if we consciously decide otherwise. If this finding stands up and works in other areas of life, neuroforecasting may lead to better voting polls or even predict changes in financial markets. To see if one can predict market behaviour by sampling a small number of people, Brian Knutson at Stanford University in California and his team scanned the brains of 30 people while they decided whether to fund 36 projects from the crowdfunding website Kickstarter. The projects were all recently posted proposals for documentary films. Each participant had their brain scanned while taking in the pictures and descriptions of each campaign, and they were then asked if they would want to fund the project. When the real Kickstarter campaigns ended a few weeks later, 18 of the projects had gained enough funding to go forward. Examining the participants’ brain scans, the team discovered that activity in a region called the nucleus accumbens had been different when they considered projects that later went on to be successful. Prediction paradox The team trained an algorithm to recognise these differences in brain activity using scan data from 80 per cent of the projects, then tested the program on the remaining 20 per cent. Using neural activity alone, the algorithm was able to forecast which Kickstarter campaigns would be funded with 59.1 per cent accuracy – more than would be expected by chance. This contrasted with what the volunteers themselves had consciously thought. When considering each proposal, the volunteers had been asked to rate how much they liked each project, and how likely they thought each one was to reach its funding goal. Unlike the activity in their nucleus accumbens regions, these ratings predicted funding outcomes with only 52.9 per cent accuracy – which is not significantly better than chance. Knutson’s team was so surprised by the findings that the group repeated the experiment with new participants and new Kickstarter campaigns – and got the same results. “This is highly fascinating,” says Stefan Bode of the University of Melbourne in Australia, “But I feel like one is left with a rather strong paradox: how can the brain ‘know’ what will be successful but the person doesn’t?” Population predictions The difference in performance might be because you have to weigh up various factors to make decisions. For example, your nucleus accumbens activity – which is associated with expecting a reward – might increase at the prospect of buying a chocolate biscuit, but other regions of your brain may weigh in, telling you that you’re supposed to be on a diet or spending less money on snacks. Even if you don’t buy the biscuit, says Knutson, the nucleus accumbens might prevail in other people, or drive you to buy the biscuit at a later date “If we can deconstruct the decision-making process in the brain, then we can identify the activity that represents the intention of what a person – on average – will eventually do,” says Knutson. “It seems that activity in the nucleus accumbens is suited to this role. It can be scaled up and generalised to a larger population.” Bode suggests that the simplest explanation for Knutson’s results is that there is something about the visual presentation of Kickstarter projects that the nucleus accumbens responds strongly to, and that it is the positive or negative response to this stimulus that predicts success in the long run. You vs your brain Individuals may decide not to take the stimulus to the nucleus accumbens into account, or to balance it against other factors, when deciding if they would like to support a project, or predicting whether other people are likely to back it. They may not even be aware of their initial positive reaction to the project – the activity in the nucleus accumbens occurs early on in the decision-making process, so may not be consciously perceived. “Hence the lack of correlation with their own predictions of what will be successful,” says Bode. But, on average, it seems that people pay attention to the nucleus accumbens more often than they ignore it, explaining why activity in this region in a small number of people can predict the behaviour of a larger population. “If we start to understand the origin of this phenomenon, this could be a great step forward in the field of neural prediction of population behaviour, and possibly be applicable to other areas, such as health and financial decisions,” says Bode. Taking other parts of the brain into account may further boost brain scans’ predictive power. When Knutson’s team trained the algorithm on whole-brain neural activity, they were able to predict Kickstarter outcomes with 67 per cent accuracy. Knutson says such neuroforecasting could be used to improve voting polls, or in situations where sample groups aren’t representative, or when it is not clear who a target audience is. “There are areas in which taking a representative sample doesn’t always predict the outcome well – voting is a great example. Perhaps neural activity could help.” Source
