Title: Do executive motor-control mechanisms regulate monetary choice and gambling?
Funder: Economic and Social Research Council

Abstract: We are often confronted with the need to take decisions that involve some element of risk. Here we ask what factors determine risk-taking behaviour when selecting one amongst a number of alternative outcomes. In particular, we focus on how the need to exercise control over one's motor actions can influence how risk-averse people are when they make monetary decisions. As an example, imagine a stock broker driving to work. Because the roads are icy, the broker has to exercise restraint while driving. Minutes later she arrives at work and immediately needs to decide on buying low-risk or high-risk stocks. Will the broker tend to buy more low-risk stocks than she would normally do as a result of the icy roads? The intriguing question posed by this example is one that may have significant theoretical and practical implications. Does the type of relatively low-level action control exercised on the road share something with the high-level executive control required for monetary decision-making when presented with superficially attractive but risky options? Do the processes responsible for both overlap, and would there be some transfer between them? Is it conceivable that slowing down to prevent the car sliding on the ice might make the broker less keen to buy high-risk stocks later on? In a laboratory version of this scenario, this is exactly what we found. We presented participants with several amounts of cash on a computer screen and asked them to select among smaller & larger amounts by pressing a key. Participants were informed at the beginning of the experiment that the higher the amount, the less probable a win. Thus, higher amounts were riskier bets. The wins did eventually translate into real cash rewards after the experiment. In some parts of the experiments, an extra signal occurred occasionally. When the extra signal occurred, one group had to execute an additional motor response, whereas a second group had to stop responding. We found that being prepared to execute an additional motor response to the extra signal increased the tendency for people to place riskier bets. This is consistent with the assumption that cognitive load can induce risk-taking behaviour in multi-task situations. Crucially, however, when the additional task required preparation to stop a motor response, it instead led to more risk-aversive monetary choices. Thus, the stop group showed essentially the behaviour described in the driving scenario above: the 'cautiousness' transferred from 'low-level' (action) control to the regulation of higher-level monetary decisions. In two further experiments we found that motor inhibition has a surprisingly persistent after-effect on monetary choice: having to stop occasional motor responses reduced monetary risk-taking even when the tasks were performed up to two hours apart. On the basis of these results we propose that control of action and high-level decision-making are intimately related. We believe that this opens exciting prospects for the development of interventions in e.g. gambling, substance abuse, & overeating. However, before this can happen, one needs a much clearer understanding of the conditions in which low-level control of action transfers to the control of higher-order decisions. The proposed research will examine this by investigating different aspects of control (e.g. slowing down in anticipation of a stop signal, withholding a response when a stop signal is presented, & long-term after-effects of stopping). The grant-linked studentship will test whether people can learn associations between specific stimuli and stopping or cautiousness, and how this might influence subsequent choice. This could lead to the development of new behavioural training programs More generally, we anticipate that this work will contribute to a better understanding of self-control and how control impairments can lead to impulsive behaviour, poor control over urges, & increased risk taking.


Research activity codes: 1.2 PSYCHOLOGICAL AND SOCIOECONOMIC PROCESSES
Health categories: MENTAL HEALTH