Psychotropic placebos reduce the misinformation effect by increasing monitoring at test

Abstract

A psychotropic placebo can help people resist the misinformation effect, an effect thought to be caused by a shift to more stringent source monitoring. When this shift occurs has been unclear. To address this issue we gave some people - but not others - a phoney cognitive-enhancing drug we called R273. Shortly afterwards, everyone took part in a misinformation effect experiment. To gather evidence about source monitoring we surreptitiously recorded time to read the misleading postevent narrative, and response time at test. Our findings suggest that people shifted to more stringent source monitoring at test. Moreover, people with higher working memory capacity (WMC) performed better than people with lower WMC - but only when they were told they had received R273, a finding that fits with research showing that WMC can confer advantages in situations demanding effortful control, but not when automatic heuristics suffice.

A sham drug improves a demanding prospective memory task

“…Consistent with research showing that people respond more accurately and slowly on a retrospective memory task when the task demands effortful control (Parker et al, 2008), our research showed benefits of a sham drug on a resource-demanding prospective memory task. Strategic monitoring for nonfocal PM target events is thought to be a capacity-consuming process, and many believe that the capacity of humans to engage in such resource-demanding processes is limited and quickly depleted (Bargh & Chartrand, 1999).…”

“…Our method was based on those used by Clifasefi et al (2007) and Parker et al (2008), who also used the BPD. The BPD is the gold standard design for investigating the effects of placebos.…”

“…Manipulating people's expectancies with sham drugs or other implicit instructions can increase their ability to perform high-effort cognitive tasks, such as with the Stroop and eyewitness memory distortion paradigms, but have little effect on low-effort cognitive activities (Clifasefi, Garry, Harper, Sharman, & Sutherland, 2007;Parker, Garry, Engle, Harper & Clifasefi, 2008;Raz, Kirsch, Pollard & Nitkin-Kaner, 2006). We were interested in the effect of people's expectancies on nonfocal PM performance because this is a task that is thought to require high effort.…”

Response

“…Upon first glance it seems to be the case because Archie consulted a doctor to obtain a prescription, researched the ethical, professional and lay perspectives and used his medical training to investigate the safety of the drug. What his research failed to uncover is that cognitive abilities have been shown to be improved (and worsened) by placebos (Clifasefi et al 2007;Parker et al 2008). Thus without targeted studies on Ritalin for performance enhancement, Archie cannot be certain that his success is not due to a placebo effect.…”

Placebo studies and ritual theory: a comparative analysis of Navajo, acupuncture and biomedical healing

“…At a minimum, healing rituals provide an opportunity to reshape and recalibrate selective attention [71][72][73]. In a more expanded model, rituals trigger specific neurobiological pathways that specifically modulate bodily sensations, symptoms and emotions.…”