Development of the Child’s Brain and Behavior. In: Reynolds CR, Fletcher-janzen E, editors. Handbook of Clinical Child Neuropsychology. Boston: Springer US; 1997. pp. 17-41. [DOI: 10.1007/978-1-4757-5351-6_2]

Pre-attentive processing in children with early and continuously-treated PKU. Effects of concurrent Phe level and lifetime dietary control

Sixty-four children, aged 7 to 14 years, with early-treated PKU, were compared with control children on visual evoked potential (VEP) amplitudes and latencies and auditory mismatch negativity (MMN) amplitudes. It was further investigated whether indices of dietary control would be associated with these evoked potentials parameters. There were no significant differences between controls and children with PKU in VEP- and MMN-indices. However, higher lifetime Phe levels were, in varying degree and stronger than concurrent Phe level, related to increased N75 amplitudes, suggesting abnormalities in attention, and longer P110 latencies, indicating a reduction in speed of neural processing, possibly due to deficits in myelination or reduced dopamine levels in brain and retina. Similarly, higher lifetime Phe levels and Index of Dietary Control (IDC) were associated with decreased MMN amplitudes, suggesting a reduced ability to respond to stimulus change and poorer triggering of the frontally mediated attention switch. In summary, the present study in children with PKU investigated bottom-up information processing, i.e., triggered by external events, a fundamental prerequisite for the individual's responsiveness to the outside world. Results provide evidence that quality of dietary control may affect the optimal development of these pre-attentive processes, and suggest the existence of windows of vulnerability to Phe exposure.

The development of visual object recognition in school-age children

This study documents the age-dependent development of visual object recognition abilities in 115 children aged 6 to 11 years, using a battery of neuropsychological tests based on Marrs model (Efron test, Warringtons Figure-Ground Test, Street Completion Test, Poppelreuter-Ghent Test, a selection of stimuli from the Birmingham Object Recognition Battery, a series of color photographs of objects presented from unusual perspectives or illuminated in unusual ways). The results suggest a maturation of complex visual perceptual abilities, possibly related to the development of the cerebral processes involved in object recognition, and could be the starting point for future investigations of these skills in impaired populations.

Neuropsychological test scores, academic performance, and developmental disorders in Spanish-speaking children

Limited information is currently available about performance of Spanish-speaking children on different neuropsychological tests. This study was designed to (a) analyze the effects of age and sex on different neuropsychological test scores of a randomly selected sample of Spanish-speaking children, (b) analyze the value of neuropsychological test scores for predicting school performance, and (c) describe the neuropsychological profile of Spanish-speaking children with learning disabilities (LD). Two hundred ninety (141 boys, 149 girls) 6- to 11-year-old children were selected from a school in Bogotá, Colombia. Three age groups were distinguished: 6- to 7-, 8- to 9-, and 10- to 11-year-olds. Performance was measured utilizing the following neuropsychological tests: Seashore Rhythm Test, Finger Tapping Test (FTT), Grooved Pegboard Test, Children's Category Test (CCT), California Verbal Learning Test-Children's Version (CVLT-C), Benton Visual Retention Test (BVRT), and Bateria Woodcock Psicoeducativa en Español (Woodcock, 1982). Normative scores were calculated. Age effect was significant for most of the test scores. A significant sex effect was observed for 3 test scores. Intercorrelations were performed between neuropsychological test scores and academic areas (science, mathematics, Spanish, social studies, and music). In a post hoc analysis, children presenting very low scores on the reading, writing, and arithmetic achievement scales of the Woodcock battery were identified in the sample, and their neuropsychological test scores were compared with a matched normal group. Finally, a comparison was made between Colombian and American norms.