PubMed leans toward the hard science side of neuroscience & psychology.
PsycInfo leans toward the social science side of neuroscience & psychology.
Web of Science is is multidisciplinary database--heavy on the sciences and including neuroscience & psychology. It's a good back up database.
Google Scholar contains a wealth of journal articles, but the search interface is much less powerful than the library's subscription databases.
If you have one great article in hand, what can you do to find more articles like it?
Follow citations backward and forward
References (older than the article at hand)
"Citing Sources" or "Cited by" (newer than the article at hand)
Click on "Related" or "Similar" articles (in Google Scholar, PubMed, and other databases)
Follow the author (in databases and/or on social media)
Look at assigned "Subjects" or "Keywords"; use them to find more articles with that same subject.
There's no perfect way to find empirical research articles.
Most empirical articles will describe a study that has been done, so you're best bet is to use the word "study" as one of your search words.
Some databases (e.g. PsycInfo, PubMed) have a special limit for different types of articles.
Also look at the bibliographies of review articles; the authors likely used empirical articles to write the review.
You are probably most used to keyword searching, in which you brainstorm search words and various synonyms.
Subject searching can be used in addition to or as an alternative to keyword searching. If you use the correct subject heading, you will capture synonyms automatically (e.g. "brain injuries" will find "brain injury" and "concussion"). How do you know what the correct subject heading is? You can look them up in many databases.
There are people whose job it is to read articles and assign subject headings to them (i.e. decide what they are "about"). It's kind of like assigning a hashtag to something in Twitter and then being able to search by that hashtag (...kind of).
