Do executive motor-control mechanisms regulate monetary choice and gambling?

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.

The proposed project is basic research on executive control mechanisms that regulate motor responses & decision-making when presented with risky choice options in healthy participants. We believe this work could have important theoretical & methodological implications for behavioural & neurological research that focuses on motor control, goal-directed behaviour, & decision-making (see Academic Beneficiaries).

We expect that our work will also have important medium & long-term implications for clinical psychology & psychiatry, and more generally, for facilitating behaviour change in the wider population (e.g. with respect to overeating). Impulse-control disorders (e.g. ADHD, substance abuse, & pathological gambling) and behaviour control issues such as over-consumption of food & alcohol have been linked to executive control, and to response inhibition in particular. The economical & social costs associated with problems in controlling impulses & urges are huge. To give only a few examples:

- The economic & social costs of Class A drug use in England & Wales are estimated at around £15.4 billion in 03/04 [a].
- Most western nations with developed gambling industries report rates of problem gambling between 0.2 & 3.5% [b].
- In 2008, almost a quarter of adults in England were obese, and in 2004, almost 7% of all deaths in England were were attributable to obesity [c].
- The estimated cost of alcohol harm to the NHS in England is £2.7 billion in 06/07 [d].

These examples indicate that a good understanding of the psychological mechanisms of controlling impulses & urges is essential. We anticipate that the implications of our work for mental health & well being will be twofold. First, we expect that the proposed project will further identify the cognitive mechanisms underlying risk-taking behaviour & clarify how people control their urges, impulses, & behaviour. This will lead to a better understanding of the aetiology of impulse-control disorders such as pathological gambling, and of why people might experience problems with controlling e.g. their eating behaviour. Second, the proposed research could also contribute to the development of new & better behavioural treatments & training programs. Several lines of evidence suggest that executive-control processes might play an important role in the treatment of impulse-control disorders [e]. Some treatments already focus on learning how to stop and reverse habitual addictive behaviour; however, the underlying cognitive mechanisms of such treatments are unclear [f]. Our work can shed light on these mechanisms. Furthermore, our pilot work has shown that training individuals in simple motor inhibition can reduce risk-taking in subsequent gambling tasks by teaching them to be generally cautious. This suggests that inhibition & executive control can be trained, which opens promising new avenues for treatment. Other studies also showed that a consistent pairing of specific alcohol-pictures to stopping in a response-inhibition task reduced the subsequent weekly alcohol intake of students; similar findings were obtained with food-related pictures and subsequent food intake [g,h]. These studies were directly inspired by our earlier work on stimulus-stop associations [i], demonstrating the impact of our previous basic research in an applied domain. The requested studentship project will further explore how such stimulus-specific learning of inhibition can influence decision-making and control over urges & impulses.

Finally, because the proposed work is on higher-level monetary decision-making & maximising gains, it could also be of interest to behavioural economists & regulators who try to moderate excessively risky decision-making in the financial sector, and more generally, to scientists & non-scientists (e.g. insurance companies) who want to understand how risk-taking behaviour can increase or decrease in multi-task situations, and how risks can be prevented.