Abstract | ||
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Dopamine (DA) is suggested to improve perceptual and cognitive decisions by increasing the signal-to-noise ratio. Somewhat paradoxically, a hyperdopaminergia (arguably more accentuated in the right hemisphere) has also been implied in the genesis of unusual experiences such as hallucinations and paranormal thought. To test these opposing assumptions, we used two lateralized decision tasks, one with lexical (tapping left-hemisphere functions), the other with facial stimuli (tapping right-hemisphere functions). Participants were 40 healthy right-handed men, of whom 20 reported unusual, “paranormal” experiences and beliefs (“believers”), whereas the remaining participants were unexperienced and critical (“skeptics”). In a between-subject design, levodopa (200 mg) or placebo administration was balanced between belief groups (double-blind procedure). For each task and visual field, we calculated sensitivity (d′) and response tendency (criterion) derived from signal detection theory. Results showed the typical right visual field advantage for the lexical decision task and a higher d′ for verbal than facial stimuli. For the skeptics, d′ was lower in the levodopa than in the placebo group. Criterion analyses revealed that believers favored false alarms over misses, whereas skeptics displayed the opposite preference. Unexpectedly, under levodopa, these decision preferences were lower in both groups. We thus infer that levodopa (1) decreases sensitivity in perceptual–cognitive decisions, but only in skeptics, and (2) makes skeptics less and believers slightly more conservative. These results stand at odd to the common view that DA generally improves signal-to-noise ratios. Paranormal ideation seems an important personality dimension and should be assessed in investigations on the detection of signals in noise. |
Year | DOI | Venue |
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2010 | 10.1162/jocn.2009.21313 | Cognitive Neuroscience, Journal of |
Keywords | Field | DocType |
paranormal belief,facial stimulus,meaningful stimulus,lexical decision task,perceptual-cognitive decision,cognitive decision,paranormal ideation,paranormal thought,calculated sensitivity,decision preference,lateralized decision task,signal-to-noise ratio,dopamine,signal detection theory,signal to noise ratio,left hemisphere | Social psychology,Neuroscience,Lexical decision task,Motor skill,Paranormal,Cognitive psychology,Psychology,Stimulus (physiology),Meridian (perimetry, visual field),Cognition,Visual field,Perception | Journal |
Volume | Issue | ISSN |
22 | 8 | 1530-8898 |
Citations | PageRank | References |
0 | 0.34 | 1 |
Authors | ||
4 |
Name | Order | Citations | PageRank |
---|---|---|---|
Peter Krummenacher | 1 | 0 | 0.68 |
Christine Mohr | 2 | 18 | 4.37 |
Helene Haker | 3 | 0 | 0.34 |
Peter Brugger | 4 | 9 | 3.58 |