Neuroenhancement (NE), the use of psychoactive substances to enhance one’s cognitive functioning without a medical indication to do so, seems to be on the rise [1–3]. Healthy individuals decide to take a substance in order to augment their cognitive capacity from a proficient level to even higher levels . Researchers have proposed a behavioral instead of a substance-based approach of NE . This approach holds that if an individual consumes a caffeinated synthetic drink (e.g. an “energy drink”, lifestyle drug NE) in the explicit expectation of increasing alertness, that individual is neuroenhancing. The same goal may be reached even more effectively with amphetamine derivatives (e.g. Ritalin; prescription drug NE), or with illicit drugs (e.g. cocaine; illicit substance NE). A substance’s actual effectiveness is of only limited relevance, for example when onset of a novel behavior is explained; it is the assumed functionality of a substance which is important to understanding the psychological roots of NE behavior .
The ethics and fairness of NE usage are currently the subject of controversy e.g. in neuroethics [6–8]. However, in the light of potential long-term negative effects on both mental and physical health one should not jump to the conclusion that NE is a reasonable and justifiable method of increasing individual performance .
Most of the published research on NE addresses epidemiological issues e.g. [1, 10, 11]. Recent studies indicate a growing prevalence of NE, especially among university students with an annual prevalence of about 17.1% in medicine students, and up to 25.4% in sports students as extreme examples . An important step in deepening the understanding of NE is to investigate what causes people to start using neuroenhancers. A handful of studies have investigated possible psychological drivers of NE [5, 8, 12–14], for example global school-related distress and experiencing school demands as overwhelming have been shown statistically to predict NE [5, 8]. It has also been suggested that students employ substances (e.g. painkillers) to cope with negative study-related outcomes . Previous recommendations for prevention have therefore focused almost exclusively on stress as a major cause of NE among students [5, 15]. There have as yet been no published experimental studies, and these are prerequisite for drawing more causal inferences about stress or other possible psychological factors in use of NE. The experimental approach to NE behavior presented here may suggest alternative starting points for prevention efforts.
Self-regulation theory provides the conceptual framework for this study . According to this theory, individuals consume NE substances as a means of self-regulating their mental capacities and in order to enhance their performance. Our hypotheses were derived from the strength model of self-control. We aimed to create an experimental setting, which tends to induce first use of NEs among undergraduate students who have never tried such a substance before.
The strength model of self-control suggests that resources for self-control can be depleted by mentally exhausting tasks. The resulting psychological state is ego-depletion. Studies have shown that this state is associated with impaired cognitive processing, enforced impulsiveness, passivity and reduced motivation . One of the strength model’s central predictions is that once finite self-control resources have been depleted, individuals will fall back on their dominant behavioral response i.e. behave according to habit. The effects of experimentally reduced self-control have been studied in various settings . For example, in the state of ego-depletion participants were susceptible to drinking more alcohol and dieters were more likely to break their diet .
Most of these ego-depletion studies sought to explain why people fall back into an undesired or unhealthy behavior. This is different from the objective of our experiment. Students may perceive NE as a functional and legitimate means of achieving their academic goals. In fact, ethical standards relating to NE, e.g. whether it is fair or unfair to use a neuroenhancer in order to improve one’s performance in university exams, are currently in dispute . NE is still an ambiguous behavior, and may be neither especially tempting nor repulsive to at least some individuals. From the perspective of the strength model ego-depletion is predictive for an individual’s dominant response to a given situation; this results in different predictions about NE for NE first-time and habitual users. Ego-depletion, as a state in which mental resources for self-regulation are minimal, will lead students for whom NE is a dominant response to take the substance, whilst potential first-time users will fall back on their dominant response: not taking the substance. Consuming a neuroenhancer may therefore represent to non-depleted first-time users a means of self-regulating (and vice versa for depleted habitual users). It is inconsistent with the strength model of self-control, to assume that high levels of stress or heavy workloads will automatically increase all students’ readiness to consume neuroenhancing substances. On the other hand, it is consistent with the theory to recognize individual differences based on the students’ habits (i.e. the experience they have already had with NE). This knowledge may prompt the design of more targeted interventions in the future.
The present study focused exclusively on students who reported having no previous experience with neuroenhancers as a means of improving cognitive performance. We investigated experimentally the hypothesis that depleting self-control will decrease the proportion of participants who will try the - for them - novel behavioral option of using a lifestyle NE substance.