Eliminating foggy-headedness seems to be the goal of many users of neuroenhancers. But can today's drugs actually accomplish this? I recently posed this question to Chatterjee's colleague Martha Farah, who is a psychologist at Penn and the director of its Center for Cognitive Neuroscience. She is deeply fascinated by, and mildly critical of, neuroenhancers, but basically in favour - with the important caveat that we need to know much more about how these drugs work. While Farah does not take neuroenhancers, she had just finished a paper in which she reviewed the evidence on prescription stimulants as neuroenhancers from 40 laboratory studies involving healthy subjects. Most of the studies looked at one of three types of cognition: learning, working memory, and cognitive control. A typical learning test asks subjects to memorise a list of paired words; an hour, a few days, or a week later, they are presented with the first words in the pairs and asked to come up with the second. Neuroenhancers did improve retention, especially where subjects had been asked to remember information for several days or longer.
The main concern with pharmaceutical drugs is adverse effects, which also apply to nootropics with undefined effects. Long-term safety evidence is typically unavailable for nootropics. Racetams — piracetam and other compounds that are structurally related to piracetam — have few serious adverse effects and low toxicity, but there is little evidence that they enhance cognition in people having no cognitive impairments.