Selective enhancement of object representations through multisensory integration
AUTHORS: Tovar D, Murray MM, Wallace MT
The Journal of Neuroscience, 40(29): 5604-5615, July 2020
Objects are the fundamental building blocks of how we create a representation of the external world. One major distinction amongst objects is between those that are animate versus inanimate. Many objects are specified by more than a single sense, yet the nature by which multisensory objects are represented by the brain remains poorly understood. Using representational similarity analysis of human EEG signals, we show that the often-found processing advantages for animate objects are not evident in a multisensory context. Neural response decoding was found to be more strongly enhanced for inanimate objects, which were more weakly decoded under unisensory conditions. A distance-to-bound analysis provided critical links between EEG and behavior. Improved neural decoding for visual and audiovisual objects was associated with faster behavior, and decoding differences between visual and audiovisual objects predicted reaction time differences. Collectively, these findings show that object encoding is distinct under unisensory and multisensory conditions.