Consider using Google Scholar’s “Advanced Search”. This is available from the menu (the three horizontal lines) at the upper left of the screen.
In Advanced Search, put your search term (putting it in quotes will search for it with the words together). Next to "Return articles published in" add the journal title. In this case, we are searching for the term placebo effect (you can also try this again with quotes) in the journal Cognitive Psychology.
Your results should all be articles from the journal you select. If you don’t get good results, consider changing your search term (for example, the word placebo alone rather than placebo effect) and also consider changing your journal title.
To get to the actual article content easily, you can add “Get it at UC” to Google Scholar, to be taken directly to the library’s site. To do this, go to Settings à Library Links à enter Berkeley in the search box.