Crossmodal attention develops in the first year of life: Cortical signatures of tactile to visual exogenous spatial cuing at 8 but not 5 months of age
Adults are able to orient their attention between different (often fleeting) sensory cues that present to different senses ("crossmodal attention"), but we cannot assume that this is the case in early life. Here we report the findings of a study in which we probed the presence of tactile to visual crossmodal links in spatial attention using event related potentials (ERP) gathered from the scalp electroencephalograms (EEG) of 5-(n = 19) and 8-month-old (n = 19) infants. Whilst recording EEG, we presented 5- and 8month-old participants with vibrotactile stimuli on one of their hands, followed by visual stimuli on the same (Congruent) or the opposite (Incongruent) hand, or no touch at all (No probe). During the presentation of these stimuli the infants eyes were oriented centrally. We subtracted No probe trials from Congruent and Incongruent trials to yield visual evoked potentials (VEPs) free from the influence of prior somatosensory processing. Comparably to prior findings in adults, 8-month-olds first negative component of the VEP was enhanced in the hemisphere ipsilateral to the probe when the visual probe was spatially congruent with the tactile cue. No crossmodal effect was observed in the 5-month-olds, indicating developments in the crossmodal coordination of attention in the first year of life.