Not so smart? "Smart" drugs increase the level but decrease the quality of cognitive effort

Area of Science:

• Cognitive Neuroscience
• Behavioral Economics
• Psychopharmacology

Background:

• The efficacy of pharmaceutical cognitive enhancers in complex, real-world tasks is not well-established.
• Existing research often focuses on simple cognitive functions, not complex problem-solving.

Purpose of the Study:

• To evaluate the impact of common cognitive enhancers on performance in a complex optimization task.
• To determine if drugs like methylphenidate, dextroamphetamine, and modafinil enhance or impair performance in tasks requiring strategic decision-making.

Main Methods:

• Utilized the knapsack optimization problem as a model for complex daily tasks.
• Compared the effects of methylphenidate, dextroamphetamine, and modafinil against a placebo.
• Measured task value, solution optimality, decision time, steps taken, and productivity.

Main Results:

• Cognitive enhancers significantly diminished the value attained in the knapsack task compared to placebo.
• While motivation may increase, the quality of effort and problem-solving strategy decreased significantly.
• Individual performance differences were reduced, with high performers declining and low performers improving.

Conclusions:

• Pharmaceutical cognitive enhancers do not enhance performance on complex optimization tasks.
• The observed decrease in the quality of effort negates any potential motivational benefits of these drugs.
• Increased randomness in solution strategies may explain the counterintuitive performance changes.