True and false recognition memories of odors induce distinct neural signatures

Jean-Pierre Royet (1) , Leri Morin-Audebrand (2, 3) , Barbara Cerf-Ducastel (4) , Lori Haase (4) , Sylvie Issanchou (2) , Claire Murphy (4) , Pierre Fonlupt (5) , Claire Sulmont-Rossé (2) , Jane Plailly (1)

1 CRNL - Centre de recherche en neurosciences de Lyon - Lyon Neuroscience Research Center
2 CSGA - Centre des Sciences du Goût et de l'Alimentation [Dijon]
3 Institute of Life Technologies
4 Lifespan Human Senses Laboratory, Department of Psychology
5 Processus mentaux et activation cérébrale

Neural bases of human olfactory memory are poorly understood. Very few studies have examined neural substrates associated with correct odor recognition, and none has tackled neural networks associated with incorrect odor recognition. We investigated the neural basis of task performance during a yes-no odor recognition memory paradigm in young and elderly subjects using event-related functional magnetic resonance imaging. We explored four response categories: correct (Hit) and incorrect (False Alarm) recognition, as well as correct (CR) and incorrect (Miss) rejection, and we characterized corresponding brain responses using multivariate analysis and linear regression analysis. We hypothesized that areas of the medial temporal lobe were differentially involved depending on the accuracy of odor recognition. In young adults, we found that significant activity in the hippocampus and the parahippocampal gyrus was associated with correct (true) recognition of odors, whereas the perirhinal cortex was associated with False Alarms and Misses. These findings are consistent with literature regarding hypothetical functional organization for memory processing. We also found that for correct recognition and rejection responses, the involvement of the hippocampus decreased when memory performances improved. In contrast to young individuals, elderly subjects were more prone to false memories and exhibited less specific activation patterns for the four response categories. Activation in the hippocampus and the parahippocampal gyrus was positively correlated with response bias scores for true and false recognition, demonstrating that conservative subjects produced an additional search effort leading to more activation of these two medial temporal lobe regions. These findings demonstrate that correct and incorrect recognition and rejection induce distinct neural signatures.

Mots clés: age effect; odor recognition memory; multivariate analysis; false memory; bias score; fmri; memory score; true memory

Domaines: Sciences du Vivant [q-bio]

Jean-Pierre Royet, Leri Morin-Audebrand, Barbara Cerf-Ducastel, Lori Haase, Sylvie Issanchou, et al.. True and false recognition memories of odors induce distinct neural signatures. Frontiers in Human Neuroscience, 2011, 5, pp.65-65. ⟨10.3389/fnhum.2011.00065⟩. ⟨hal-01137147⟩