What is the difference between the words subjects and participants?

When describing participants in a study, is there a difference in APA Style® between the terms subjects and participants?

Write about the people in your study in a way that acknowledges their participation but is also consistent with the traditions of the field in which you are working.

Thus, although descriptive terms such as college students, children, or respondents provide precise information about the individuals taking part in a research project, the more general terms participants and subjects are also in common usage. Indeed, for more than 100 years the term subjects has been used within experimental psychology as a general starting point for describing a sample, and its use is appropriate.

Subjects and sample are customary when discussing certain established statistical terms (e.g., within-subject and between-subjects design).

(adapted from the sixth edition of the APA Publication Manual, © 2010)