Cambridge Brain Sciences offers a free online tool for testing mental performance. The site features multiple tests for memory (4), reasoning (4), concentration (3) and planning (3).  While there are many brain training apps and sites CBS is often used as a research platform and has some impressive credentials. Biohackers use this site for testing different nootropics. A measurable cognitive gain could show the effectiveness from specific drugs. The only downside to using the CBS that I have noticed is that the site is quite slow to save results and load graphs at the end of each experiment.

Via CambridgeBrainSciences.com:

Cambridge Brain Sciences bridges the gap between cutting edge neuroscience and everyday life. Using our scientifically-validated online tests backed by millions of data sets and hundreds of academic journal articles, we provide cognitive assessment solutions for a wide variety of consumer, academic and corporate uses.

For consumers – www.cambridgebrainsciences.com allows consumers to evaluate memory, reasoning, attention, planning and problem solving using some of the world’s most scientifically valid tests. Consumers can track scores over time and compare their results against our database of over 5 million data sets. To date, we’ve had well over 1 million people log on to www.cambridgebrainsciences.com, and are constantly exploring new and better ways to apply our tests to address current questions in the cognitive neurosciences.