Human cortical networks underlying perceptual decision making: fMRI and MEG studies of tactile discrimination.
Human Cognitive and Systems Neuroscience
Final Report Abstract
In this project, we have two major findings. First, the importance of the right postcentral area in tactile spatial discrimination became clear. In combination with our previous results, it seems to be right-hemisphere specific, independent of left or right hand tactile pattern task (only tested in right-handed subjects). Second, we have revealed a detailed cortical processing hierarchy and thus the functional distinction of different human brain areas involved in a perceptual decision task. We were able to dissociate the neuronal correlates of perceptual decision (anterior intraparietal sulcus and anterior insula) from those engaged in motor preparation (e.g., supplementary motor area and dorsal premotor cortex). Apart from providing such a distinction, our experimental design further enabled us to extract information at higher ‘temporal’ resolution than that commonly achieved by typical fMRI experiments. Using this approach we could demonstrate a functional gradient reflecting the transition from sensory to motor processes across decision-related cortical areas. Our findings obtained by MEG and fMRI indicate that the anterior insular could sit on top of this hierarchy and might be the key node linking sensory and motor areas. In addition, we provide a valuable experimental design and analytical approach to fMRI data that revealed an otherwise hidden processing hierarchy and that perhaps could also be applicable in other fields of cognitive neuroscience.
Publications
- 2015. Cortical correlates of perceptual decision making during tactile spatial pattern discrimination. Hum Brain Mapp
Li Hegner Y, Lindner A, Braun C
(See online at https://doi.org/10.1002/hbm.22844)
