Neurophysiological mechanisms of recognition fragmented images by five- to six-year-old children

Behavioral indices and event-related potentials (ERP) were analyzed in five- to six-year-old children who were shown a set of previously unseen fragmented drawings of familiar images. These children recognized less fragmented images than seven- to eight-year-old children. At the age of five to six years, there was no increase in N350–400 prefrontal negativity and slow positive complex, which is characteristic of mature recognition that involves executive control. Comparison of ERP for recognized vs. unrecognized stimuli revealed a significant increase in the P300 and N400 amplitudes in the right occipital area. Note that, in children of this age, there were no significant differences between reactions to recognized and unrecognized images in the lateral extrastriate cortex (T₅/T₆), which is the key structure for recognition of familiar images via integration of their sensory features. Our data suggest that in five- to six-year-old children recognition of fragmented images has specific features determined by immaturity of the executive control and insufficient involvement of the ventral visual system.