Institut für Psychologie: Kolloquium

Am Dienstag, den 14. November 2017, 9:15 Uhr findet in Gebäude 23, Raum 4 das nächste Institutskolloquium statt, zu dem wir Sie herzlich einladen.

Dr. Phil. Dipl.-Psych. Rea Rodriguez-Raecke (RWTH Aachen) hält einen Vortrag mit dem Titel "The challenge of masking an aversive odor".

Abstract: Hypothesizing that participants cannot discriminate a fully-masked odor from the pure dominant odor, the present experiment aimed at exploring whether perception of a masked odor can be enhanced using a reinforcing feedback paradigm. Two similarly smelling stimuli were presented to participants as "odor pairs", namely the pleasant, lemon odor of pure citral and a mixture of citral and minor amounts of the unpleasant, goat-like smelling caproic acid, and participants had to decide whether they were the same or different; experiments were performed with fMRI. Accuracy of this task was incentivized with a possible monetary reward. The participants rated both odors as isopleasant and isointense but odor quality ratings differed. The accuracy in detecting the difference and the similarity, respectively, was significantly better than chance level differentiating odor pairs with the same odor stimuli, but at chance level for differing odor stimuli. We observed increased activation of the left insula and ventral striatum/putamen in the pure odor compared to the odor mixture. A subgroup of subjects that was established using the signal detection theory and designated as learners showed a significant improvement throughout the task and showed a related activation of midcingulate cortex, operculum and primary somatosensory cortex compared to non-learners. Results were considered relevant with a p < 0.05 family-wise error (FWE) correction for whole-brain comparison on the cluster level. We conclude that these areas are involved in odor discrimination learning, and that the extent and location of neuronal processing of odorants depends on even subtle changes in odor quality.