At 2:31 PM -0500 1/2/02, Charlotte Manly wrote: >In other words, it really _is_ all in their heads. ;) Seriously, though, >one of the nice things about brain imaging methods is they provide >somewhat more tangible evidence of things at the psychological level. But >ya gotta wonder... If the study's authors didn't expect to find brain >correlates of ameliorated depression in placebo responders, where did they >expect to find a change associated with the placebo response? In the >heart?
I suspect that they took seriously the claims that fMRI studies were identifying a _mechanism_ of action for antidepressants, and that therefore the changes in brain function were an index of the cause of antidepressant action. The key terms, of course, are "correlates" and "associated with". Given the above assumptions of causality, they probably expected to find different brain mechanisms involved with drug action and placebo effects. Their actual findings point to at least two conclusions: 1) Third variable. The changes in brain function were an index of behavioral change, which could in term be produced _either_ by drug or by placebo effect, rather than an index of a mechanism of change. 2) It's all placebo. The minor differences between the drug and placebo effects were due to the discriminability of the side effects of the antidepressants (true double blinding with psychoactive drugs is nearly impossible). * PAUL K. BRANDON [EMAIL PROTECTED] * * Psychology Dept Minnesota State University, Mankato * * 23 Armstrong Hall, Mankato, MN 56001 ph 507-389-6217 * * http://www.mankato.msus.edu/dept/psych/welcome.html * --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED]
