ISDN2014_0132: Early childhood development of visual texture segregation in full‐term and preterm born children

Most of the studies that have focused on the development of the visual system in children using visual evoked potentials (VEPs) have used stimuli soliciting only one level of visual processing. However, the perception of a visual scene requires a multitude of analytical processes ranging from the encoding of various characteristics of the visual stimuli, to the processing of top-down information and finally leading to segmentation of forms and recognition of stimuli. Numerous studies have shown that visual texture segregation can be objectively studied with texture segregation visual evoked potentials (tsPEVs). The purpose of the present study was to characterize the developmental pattern of higher-level visual processing during early childhood using tsVEPs in (1) full-term born children, and (2) children born prematurely. For this purpose, we recorded EEG during visual stimulation in 15 typically developing children born full-term in three age groups (12, 24, 36 months of age) and compared their tsPEV responses to 43 age-matched children born prematurely. Four different visual stimuli were presented: two low-level (lines homogeneously oriented to the right or left) and two high-level (orientation-defined checkerboard composed of 90° line gradients oriented concentrically or outwards). The tsVEP was obtained by subtracting low-level from higher-level responses and dividing by two. Results showed a significant latency reduction of the N2 component between 12 and 36 months in children born full-term. In addition, smaller N2 amplitude was found in preterm children at 12 months, compared to full-terms. In summary, our results indicate that (1) the texture-segregation maturation process takes place between 12 and 36 months in typically developing children and (2) this process is delayed in 12-month preterm children but seems to gradually recover, as their tsVEP pattern responses are similar to them at 24 and 36 months of age.