The first paper of my PhD project has been accepted in the Journal of Cognitive Neuroscience.
The behavioral and neural effects of language on motion perception
Jolien Francken, Peter Kok, Peter Hagoort, Floris de Lange
How do language and perception interact? We investigated whether language-perception interactions are specific to the language-dominant left hemisphere by comparing the effects of language on visual material presented in the right and left visual fields. Furthermore, we determined the neural locus of the interaction using fMRI. Subjects performed a visual motion detection task. On each trial, the visual motion stimulus was presented in either the left (LVF) or in the right visual field (RVF), preceded by a centrally presented motion word (e.g., ‘rise’). The motion word could be congruent, incongruent or neutral with regard to the direction of the visual motion stimulus that was presented subsequently. Subjects were faster and more accurate when the direction implied by the motion word was congruent with the direction of the visual motion stimulus. Interestingly, the speed benefit was present only for motion stimuli that were presented in the RVF. We observed a neural counterpart of the behavioral facilitation effects in the left middle temporal gyrus, an area involved in semantic processing of verbal material. Together, our results suggest that semantic information about motion retrieved in language regions may automatically modulate perceptual decisions about motion.