Useful Standardized Tests?

I'd say Project Euler is not generally the best way to learn programming languages, since it has a heavy focus on number-theory and in many languages the core reason to learn that language is to apply it towards a particular domain with very different demands (server-side web development, scientific computing, etc).

As far as syntax, most languages have "Koans" now that take you through syntax and standard data structures much more conveniently than a manual.

For starting to learn new programming languages, a less conventional "standardized" test is solving Project Euler problems in that language.

I don't think that's a good test. It ignores a lot of knowledge about APIs that aren't necessary for solving mathematical problems. The Java Programmer Language Certification would be an example of a test for Java.

AFAIK, there is really no good standardized exam for neuroscience. Eg, see someone ask the same question and get no replies here: http://www.funfaculty.org/drupal/node/4331

The old Kandel textbooks used to have questions at the end of at least some chapters, but recent editions do not have them IIRC.

If you're interested in the medical side of things, there's a lot of good practice multiple choice questions you can do for psychiatry and/or neurology, that med students use when preparing for Step I. USMLERx and UWORLD are both good qbanks, but they're fairly expensive and you'll only want a subset of them.

For awhile I was going through CalTech's 100 Questions: http://www.cns.caltech.edu/academics/100questions.html , but I only got until #18 or so before my interests change too much to make it worthwhile to continue. (Some of which you can find here: http://brainslab.wordpress.com/category/100-questions/.)

Please update me if you find anything, since I'd be curious about this too.

For high school level knowledge, finding Cambridge International Exams past papers is a fairly good option. The exams are done twice a year, and go back to about 2003 IIRC.

Old math and computing Olympiad problems are good for testing problem solving skills.

Anki is a great way to solve the problem that you are having for topics like cognitive science and neuroscience. If you manage to translate the book you are reading into Anki flashcards and you successfully learn those flashcards you have the knowledge. Anki gives you automatic testing.

One idea: figure out why specifically you want to learn neuroscience (for some project? thing you want to write? question you want to answer?) and then let your learning facilitate the thing you are doing as a test of whether you're learning well or not. (E.g. post an essay about your neuroscience-based conclusions on an online community for neuroscientists and see what they think.) Neuroscience is a bit of a bad fit for this kind of learning by doing though.