MEG measures of covert orienting and gaze processing in children

We investigated developmental differences in the cortical attention processing network using magnetoencephalography (MEG) and a spatial cueing task in 7-8 and 12-13 year old children. The cueing paradigm consisted of a centrally presented face with left or right averted eye-gaze in the gaze cue condition, and a central face with straight gaze presented with a cue stimulus to the left or right of the face in the peripheral cue condition. Cue congruency was 50 %. MEG was recorded during the two conditions and event-related beamforming was used to determine the timing and location of the brain activity related to target detection with the two types of cueing. The MEG data showed no age differences in the eye-gaze condition, but a developmental difference characterised by slower and more diffuse activations for peripheral cues in the younger versus the older age group. In the 7-8 year olds activation peaked around 300 ms, and was localised to left inferior frontal gyrus as well as posterior areas related to visuo-spatial processing. The 12-13 year olds showed a temporoparietal pattern of activation characteristic of spatial reorientation which resembled that seen for adult participants using the same paradigm (Nagata et al. 2012). The activation peaked around 200 ms and was localised to the left superior frontal gyrus, middle frontal gyrus but bilaterally near the temporoparietal junction. The data indicate maturational changes in brain activity for peripheral cueing.