How modafinil affects your brain


“The best idea we have is that by directly altering the concentration of a group of chemicals in the brain – called ‘catecholamines’ – modafinil upregulates activity in attention and executive control networks in the brain,” the authors tell Tech Insider. “These changes are then hypothesized to allow individuals to perform better on cognitive tasks: particularly those requiring good focus and problem solving.”

In their review of the literature on modafinil, Oxford researchers Ruairidh Battleday and Anna-Katherine Brem found that it didn’t seem to have any particularly serious side effects and didn’t seem likely to cause dependency — though there are still unanswered questions there.

Battleday and Brem reviewed 24 studies that assessed how modafinil affected healthy non-sleep deprived people’s minds (they considered 267 studies, but rejected those that weren’t placebo controlled, used unhealthy subjects, or tested animals and not people). The fact that subjects were healthy is an important distinction — many of the ways we look at drugs that affect thinking ability are designed to assess people with cognitive deficiencies.

Most studies could be broken down into either “basic” or “complex” tests of cognitive function, Brem and Battleday tell Tech Insider.

Basic tests assess just one sub-component of cognition and tend to be very simple tasks. On these tests, the effects of modafinil were mixed. It was on complex tests that the authors found consistent improvement, especially in terms of attention, the ability to focus on a task and process relevant information; learning and memory; and executive function, which includes the ability to take in information and use it to come up with plans or strategies.

These complex tasks are much better ways to answer the question of “does this substance actually improve cognitive ability” than the basic ones, the authors tell Tech Insider.

“Rarely in life do we spend an entire day using a sole cognitive sub-domain – attention, for example. Rather, we constantly plan, predict, and problem solve – all of which involve marshaling subdomains of cognition and integrating their output – over varying tasks and difficulties,” they wrote in an email. “It is in this sense that complex tasks can approximate everyday functioning better than simple.”

As for how modafinil works, we still really don’t know. It was originally designed as a treatment for narcolepsy to keep people awake. But no one is entirely certain how it affects cognition.