Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Pattern over time in the research methodologies used to assess motivation.
| Year | Brain techniques | Behavioral tasks | Questionnaires | Total |
|---|---|---|---|---|
| 1956 | 1 | 1 | ||
| 1964 | 1 | 1 | ||
| 1968 | 1 | 1 | ||
| 1978 | 1 | 1 | ||
| 1998 | 2 | 2 | ||
| 2002 | 2 | 1 | 3 | |
| 2003 | 1 | 1 | 2 | |
| 2004 | 1 | 2 | 3 | |
| 2005 | 1 | 1 | ||
| 2006 | 1 | 1 | 2 | |
| 2007 | 1 | 2 | 2 | 5 |
| 2008 | 1 | 3 | 3 | 7 |
| 2009 | 2 | 8 | 6 | 16 |
| 2010 | 3 | 6 | 7 | 16 |
| 2011 | 1 | 6 | 5 | 12 |
| 2012 | 5 | 10 | 5 | 20 |
| 2013 | 3 | 7 | 12 | 22 |
| 2014 | 6 | 8 | 13 | 27 |
| 2015 | 13 | 18 | 24 | 55 |
| 2016 | 7 | 13 | 12 | 32 |
| 2017 | 2 | 5 | 5 | 13 |
| Total articles | 46 | 96 | 99 | 241 |
