Object sensitivity in subcortical nuclei and their functional connections with cortical areas
33.324, Sunday, May 12, 8:30 am - 12:30 pm, Royal Ballroom 6-8
Lan Wang1, Zhentao Zuo1, Peng Zhang1, Sheng He1,2; 1State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, 2Department of Psychology, University of Minnesota, Minneapolis, Minnesota, United States of America
Behaviors from blindsight patients as well as studies using interocular suppression suggest that the human subcortical pathway might be capable of processing object category information. Using functional MRI, we investigated subcortical response properties as well as functional connectivity patterns during object perception. During the experiment, subjects viewed objects from four different categories (tools, faces, phase-scrambled tools, phase-scrambled faces). Luminance and RMS contrast were matched for different stimuli. fMRI activity in the SC and LGN showed stronger responses to intact objects than to scrambled objects. We also performed granger causality analyses to investigate the functional connectivity of these subcortical regions with cortical regions underlying visual object processing. Preliminary results suggested a number of interesting connection patterns for different subcortical nuclei. For example, the left and right SC might have different connection patterns during object perception: although left SC showed more robust object sensitivity in terms of response amplitude, its signal was not related to responses in cortical areas; whereas right SC showed more correlation with responses in cortical areas, including both the parietal and fusiform areas. Thus we found object sensitivity in some subcortical structures, such as the SC and LGN. Preliminary results showed that subcortical nuclei might have differential patterns of communication with cortical regions during object information processing.