Methods for the Assessment of Multisensory Processing: Behavioral and Neuropsychological Approaches

Since birth, we learn about the perceptual and social world through our senses. Learning to appropriately bind multisensory information is key to effectively interact with our surroundings. In this chapter, we will review the behavioral, computational, and neurophysiological methods used to assess multisensory processing in healthy adult individuals. In the first part, we will provide an overview of fundamental principles governing the activity of multisensory neurons in the animal brain since these principles still provide an influential framework for the investigation of multisensory processing in humans too. In the second part, we will present a series of behavioral paradigms that have been adopted in the past 20 years to assess multisensory processing, particularly focusing on the difference between paradigms assessing multisensory integration and paradigms assessing crossmodal interactions, in which stimulation of one sensory system affects the experience in a different sense, typically leading to illusory percepts. The last part will provide a critical overview of electrophysiological and neuroimaging approaches to measure multisensory interactions in the human brain.