The use of “smart drugs” to enhance productivity in academic and workplace settings is on the rise. A recent study published in Science Advances examined the effects of three popular smart drugs – methylphenidate, modafinil, and dextroamphetamine – on real-life tasks. The researchers hypothesized that these drugs, which affect dopamine and norepinephrine, would influence motivation and effort, ultimately leading to improved performance.
The study involved forty participants between the ages of 18 and 35. The participants were randomly assigned to four groups and attended four testing sessions. In each session, they were given one of three popular smart drugs or a placebo. The drugs were administered in a double-blinded manner, meaning neither the participants nor the researchers knew which drug was being given.
The researchers used a task called the “knapsack task” to evaluate the participants’ cognitive performance. This task involves solving a complex optimization problem where participants have to select items with certain weights and values to maximize the overall value while staying within a weight limit. The difficulty of the task was designed to simulate real-life complex tasks that people encounter.
Additionally, the participants performed several cognitive tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) to assess their baseline cognition. These tasks evaluated reaction time, spatial planning, spatial working memory, and response inhibition.
The results showed that participants correctly solved an average of 50.3% of the knapsack instances. The difficulty of the instances was assessed using a metric called Sahni-k, which had previously been successful in predicting human performance in the task. As the Sahni-k value increased, there was a significant decrease in performance.
The researchers found that the drugs did not significantly improve participants’ ability to find solutions to the knapsack problem instances. However, the drugs did lead to a significant decrease in the overall value attained, indicating a lower quality of work.
The number of moves made by participants to select items also increased under the influence of the drugs, indicating enhanced motivation when measured in terms of time spent or number of moves, but with mixed effects on speed.
Furthermore, the study examined the quality of the moves made by participants and found a decrease in quality as task difficulty increased. Although the drug treatments did not significantly reduce the likelihood of finding a solution in the task, they did lead to a decrease in the overall value attained. Effort, as measured by time spent and number of moves, significantly increased on average under the influence of the drugs. However, participants became more erratic in their decision-making when under the influence of the drugs.
Interestingly, the researchers observed that participants who performed above average under the placebo tended to perform below average under the drugs, and vice versa. This suggests that the drugs affected individuals differently based on their initial performance levels.
The researchers also observed that the drugs had negative effects on performance in the CANTAB tasks, consistent with previous studies. However, they could not predict the individual effects of the drugs in the knapsack task based on CANTAB scores or the effects of the drugs in the CANTAB tasks.
The knapsack task employed in this study reflects the challenges encountered in everyday problem-solving scenarios. Therefore, this research provides valuable insights into how medications may improve the day-to-day functioning of individuals with conditions like ADHD. It also paves the way for future discoveries of truly effective smart drugs that not only increase effort but also enhance the quality of effort.
The study, “Not so smart? “Smart” drugs increase the level but decrease the quality of cognitive effort“, was authored by Elizabeth Bowman, David Coghill, Carsten Murawski, Peter Bossaerts.