Neural dynamics underlying coherent motion perception in children and adults

• Main Authors: Catherine Manning, Blair Kaneshiro, Peter J. Kohler, Mihaela Duta, Gaia Scerif, Anthony M. Norcia
• Format: Article
• Language: English
• Published: Elsevier 2019-08-01
• Series: Developmental Cognitive Neuroscience
• Online Access: http://www.sciencedirect.com/science/article/pii/S1878929318301713

Motion sensitivity increases during childhood, but little is known about the neural correlates. Most studies investigating children’s evoked responses have not dissociated direction-specific and non-direction-specific responses. To isolate direction-specific responses, we presented coherently moving dot stimuli preceded by incoherent motion, to 6- to 7-year-olds (n = 34), 8- to 10-year-olds (n = 34), 10- to 12-year-olds (n = 34) and adults (n = 20). Participants reported the coherent motion direction while high-density EEG was recorded. Using a data-driven approach, we identified two stimulus-locked EEG components with distinct topographies: an early component with an occipital topography likely reflecting sensory encoding and a later, sustained positive component over centro-parietal electrodes that we attribute to decision-related processes. The component waveforms showed clear age-related differences. In the early, occipital component, all groups showed a negativity peaking at ˜300 ms, like the previously reported coherent-motion N2. However, the children, unlike adults, showed an additional positive peak at ˜200 ms, suggesting differential stimulus encoding. The later positivity in the centro-parietal component rose more steeply for adults than for the youngest children, likely reflecting age-related speeding of decision-making. We conclude that children’s protracted development of coherent motion sensitivity is associated with maturation of both early sensory and later decision-related processes. Keywords: Evoked potentials, Visual development, Motion perception, Direction perception, Electroencephalography, Component decomposition