Social Cognitive and Affective Neuroscience Advance Access published online on March 3, 2009
Social Cognitive and Affective Neuroscience, doi:10.1093/scan/nsp005
fMRI-activation patterns in the detection of concealed information rely on memory-related effects
1Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Germany, 2Laboratory for Social and Neural Systems Research, University of Zurich, Switzerland, 3Department of Neuroradiology, and 4Department of Psychology, Interdisciplinary Research Group Forensic Psychophysiology, Johannes Gutenberg-University Mainz, Germany
Recent research on potential applications of fMRI in the detection of concealed knowledge primarily ascribed the reported differences in hemodynamic response patterns to deception. This interpretation is challenged by the results of the present study. Participants were required to memorize probe and target items (a banknote and a playing card, each). Subsequently, these items were repeatedly presented along with eight irrelevant items in a modified Guilty Knowledge Test design and participants were instructed to simply acknowledge item presentation by pressing one button after each stimulus. Despite the absence of response monitoring demands and thus overt response conflicts, the experiment revealed a differential physiological response pattern as a function of item type. First, probes elicited the largest skin conductance responses. Second, differential hemodynamic responses were observed in bilateral inferior frontal regions, the right supramarginal gyrus and the supplementary motor area as a function of item type. Probes and targets were accompanied by a larger signal increase than irrelevant items in these regions. Moreover, the responses to probes differed substantially from targets. The observed neural response pattern seems to rely on retrieval processes that depend on the depth of processing in the encoding situation.
Keywords: deception; guilty knowledge test; concealed information; skin conductance; response conflict
Correspondence should be addressed to Matthias Gamer, Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany. Email: m.gamer{at}uke.uni-hamburg.de.
Received August 28, 2008. Accepted December 31, 2008.