Multimodal Imaging of Face Recognition in Patients with Prosopagnosia and Healthy Controls Semineri

Tarih: 16.12.2014
Yer: BÜ BME Binası AZ-19 Kandilli

Maria Antonieta Bobes-Leon, PhD- Cuban Neuroscience Center, Cuba

Face recognition models postulate two independent streams of processing, one  for personal semantic information and another for affective reaction to this identity. This idea comes mainly from double dissociation between conscious identity recognition (overt) and unconscious emotional response (covert) to familiar faces present in prosopagnosia and Capgras syndrome. However, the neural circuitry underlying overt and covert face recognition is still barely unknown. Two pathways, one(ventral)  linking the Occipital and Fusiform Face Areas (OFA/FFA) and Anterior-Inferior Temporal (AIT) cortex and another (dorsal) linking OFA/FFA with more anterior areas of the  emotional system, such as insula and orbitofrontal cortex could be candidates for underlying  these  processes. Here we use multimodal neuroimaging (VBM, fMRI and DTI tractography) to explore the integrity of the neural pathways underlying face processing system both in typical observers and in two patients: one case with prosopagnosia (showing signs of covert recognition), and another patient exhibiting Capgras syndrome, in whom  the affective responses to consciously recognized familiar faces was absent. In the prosopagnosic patient, the ventral path was impaired, whereas the dorsal path to pre-frontal regions were preserved. The opposite pattern was present in the Capgras patient. These dissociated pathways could respectively support conscious and unconscious processes in these patients and possibly in normal face recognition. Finally, multivoxel pattern analysis (MVPA) was used in typical observers to decode emotional valences and familiarity in target areas of the two pathways. Valence was decoded accurately in areas of the posited covert pathway, whereas familiarity was decode accurately in areas of the posited overt pathway. These results provided neurophysiologic support for dual path model of face processing.

 About the Speaker:

Maria Antonieta Bobes-Leon received her B.Sc. Degree from Havana University, Biology Faculty in 1981. She got her PhD degree from National Scientific Research Centre (CNIC) in 1990 with the thesis title “Face Recognition and Event Related Potentials”. She worked as an associate researcher and later senior researcher at CNIC in 1981-1996. She was head of Psychophysiology laboratory at Cognitive Neuroscience Department in Cuban Neuroscience Center from 1988 to 1998. She has been head of the Cognitive Neuroscience Department in Cuban Neuroscience Center since 1998 and academic coordinator at the same center since 2004. She has involved in several research projects including development of a software package for the acquisition of evoked potentials of different sensory modalities, clinical applications of auditory brainstem evoked potentials, cognitive rehabilitation in brain damage patients, face processing in neural system, biological basis of violence. She has published more than 60 papers in peer-reviewed journals. She participated in international collaborative projects with Psychology Departments of University of Edinburgh (UK),  University of Glasgow (UK), Universidad Autonoma de Granada (Spain), National Autonomous University of Mexico (Mexico). She was awarded with Annual reward of the Cuban Academy of Science in 1996 for her work “Electrophysiological evidences of independent processing modules for faces and words” and 1998 for her work “Brain mechanisms of visual attention” and Annual reward of the Minister of Higher Education for her contribution to scientific research in 2001.