The results support the hypothesis that NIDCAP in the NICU enhances aspects of executive function underlying visual-motor and memory functions.
As newborns at 2wCA
 the children who were in the NIDCAP-group showed significantly better neurobehavioral functioning as measured with the APIB
 than did the control-group children as newborns. The correlation analysis on neurobehavioral functioning measures from the newborn to the school-age study point showed, in specific, that the newborns with better attention organization displayed better EF later as reflected in the Organization (i.e. Gestalt appreciation) score in the Delayed Recall (i.e. memory) condition of the Rey-Osterrieth Complex Figure Test
The demonstrated superiority in executive functioning measures for E- versus C-group IUGR children in spite of academic and IQ equivalence is consistent with the results of other investigators, who suggest that despite considerable shared variability, the measures of executive functioning maintain unique variance that is not encapsulated in the construct of global intelligence
. The demands for the skill set considered under the general rubric of EF including planning, response inhibition, working memory, organizing and strategizing ongoing behavior increase significantly in middle and later school years when the child is increasingly required to monitor and self direct behavior. It may be hypothesized that the impact of EF differences may become increasingly apparent at a later age since it is reflected in measures of independent functioning and the development and maintenance of appropriate social relationships of increasing importance at later ages.
Electrophysiological function at school-age was also improved. Similar to the earlier findings for the IUGR sample in the newborn period (2wCA)
 and its more recent replication study with a second IUGR sample
, NIDCAP effects on EEG coherence resulted in a pattern of decreased short distance connectivity between multiple adjacent brain regions. However, it appears to have also resulted in increased long-distance, across-midline bilateral frontal to occipital connectivities in the E-group. This is similar to the pattern found in a comparable-in-gestational age AGA preterm sample in the newborn period
 as well as an extremely early-born AGA sample at 8 years
. Without the experimental intervention in the preterm period the IUGR-preterm-born school-age children in the control group who did not receive experimental intervention in the preterm period show continued excessive cortical short-distance connectivities, possibly a carry-over from the multiple pathological influences generated by the IUGR condition. The IUGR children who received the NIDCAP intervention in the NICU appear to have preserved some of the plasticity evidenced in increased long-distance coherences in an AGA school-age sample, despite the IUGR condition. Presumably such connectivity is more conducive to better differentiated mental control function and visual motor integration
[16, 77, 80]. In particular, Coherence factor 3, stronger in the IUGR E-group, appears to suggest increased connectivity between the dorso-lateral frontal cortex and bilateral occipital parietal regions. These regions are known to be active in visual spatial working memory
[81–85] and thought to be largely independent of IQ
. Furthermore, better connectivity was correlated with better ROCF performance, an integrative visual spatial working memory task, in the IUGR E-group. Thus, the intervention appears to ameliorate excessive coupling noticeable still at school-age in the IUGR control group children, and to enhance cortical function in long distance connectivities supportive of differentiated attention regulation, visual spatial memory organization and executive function in the IUGR experimental group children. This finding of enhanced long distance cortical coupling and its implication for more effective executive functioning has been supported by others
[16, 78] who investigated whether varying demands on central executive processes are reflected by differences in coherence activity. Their results indicate that a decrease of anterior upper alpha short-range connectivity and a parallel increase of fronto-parietal long-range coherence may be considered as plausible candidates for the neural correlates of central executive function.
This is the first report of NIDCAP effectiveness at school-age for IUGR preterm-born children, and the first documentation of brain structural differences for IUGR preterm born children at school-age. The tighter distribution of right and left cerebellar volume measures around the group mean for the experimental as compared to the control group speaks not only to the greater symmetry of right and left cerebellum in the experimental group but also perhaps a better opportunity to develop than the control group experienced. The larger tissue volumes identified consistently for the right and left cerebellum are interpreted to reflect intervention-enhanced connectivity of the cerebellum with multiple other cortical regions
[47, 66, 86–92] in particular frontal and prefrontal cortex
 as in this study corroborated by the cortical coherence findings. The findings substantiate the cerebellum’s increasingly recognized, important role in complex behavior, including visual-spatial organization and complex integrative and executive function as exemplified in poor ROCFT performance
[94, 95] and cognitive and mental control functions
[44, 92, 96].
 for a healthy sample (n = 433) of children from 4 to 18 years of age indicated mean cerebellar volumes of 132.82 cm3, which corresponded to 10.52% of brain parenchyma, comparable to the 10.55% found for the IUGR sample’s E-group while the IUGR C-group’s cerebellar volume was only 9.88%, a significant difference (p = 0.04).
Thus, the current study shows the cerebellum amenable to very early behavioral intervention during the time of its most rapid development
. The cerebellar findings are in keeping with the improved ROCFT findings and the coherence findings of enhanced broad frontal to broad occipital long distance connectivities observed in the experimental group. The results identified for the IUGR preterm born school-age sample are internally consistent and consistent with the most recent literature on the cerebellum and its functions. They are also consistent with two IUGR preterm studies in the newborn period. They speak to the effectiveness of the experimental intervention also for severely IUGR preterm infants who are already compromised in the womb with respect to the growth and function of multiple organs including brain. The results provide additional evidence for the effectiveness of the intervention delivered in the immediate newborn period. When the study children reached school-age, those who had been in the NIDCAP group demonstrated significantly better spatial visualization and mental control than those who received standard NICU care. The EEG-derived measures of cortical connectivity also successfully differentiated E-group from C-group children at school-age and corroborated the neuropsychological findings in terms of the neural pathways implicated. The findings, although limited by the small sample size, potentially have important implications for the amelioration of the specific learning disabilities with which so many early born IUGR children struggle. The study’s findings contribute to the validation of the hypothesis that underlies NIDCAP, namely that the fetal brain in the late second and throughout the third trimester is differentially sensitive to the repeated stressful events experienced in the NICU, and that this vulnerability may be compensated for by consistent individualized developmental care implementation. While the specific pathways involved in NIDCAP effectiveness are not fully understood, consistent implementation of individualized cue-based reintegration times specifically to support reliable re-synchronization of the autonomic, motor and state systems as well as attention organization appears to strengthen the infant’s self regulatory capacities. In the face of the many demands of intensive care, this individualized support appears to provide an opportunity for the immature brain to develop its connectivities in a more adaptive manner than is the case in a more traditional faster paced approach to intensive care. The reliable behavioral subsystem reintegration may provide protection of programmed cell death and of the development of better inter-cortical connectivities which may guard against compromised brain development. The neurobiological processes underlying NIDCAP effectiveness are speculative. It is postulated that NIDCAP processes may involve stabilization of the NMDA (N-methyl-d-aspartate) axis, protection against neurocytotoxic damage, lowered sensory and pain thresholds, and increased stability with modulated thresholds of reactivity and sensitivity
[99–102]. Other potential mechanisms, inferred from results of differential mothering and sensory experience experiments in animal models, suggest that continuity and reliability of maternal care promotes hippocampal synaptogenesis as well as spatial learning and memory through systems known to mediate experience-dependent neural development
[103, 104], which appear to also include the cerebellum
. All of these effects may enhance NIDCAP group preterm infants’ capacity to take advantage of environmental offers in and beyond discharge from the stressful NICU environment.
In the NIDCAP model of caregiving, the infant’s behavior guides the caregiver in improving the infant’s comfort and in decreasing the infant’s stress. The NIDCAP approach focuses on individualization of care in the NICU as based on each infant’s behavioral cues, to support each infant’s strengths and to reduce the level of stress and pain experienced by the infant. Conscious, deliberate, and thoughtful caregiving and the consistent familiar presence of, and intimate contact with, the parents and other family members appears to support the infant to be more calm and self-regulated. This in turn appears to facilitate brain development
[105–107]. This study provides the first indication that NIDCAP may demonstrate specific beneficial brain developmental effects for IUGR experimental group children not only in infancy but likely also into school-age; this is very encouraging.
Interpretation of the findings however requires much caution. The study’s most serious limitation is the small sample size. Further substantiation by larger longitudinal follow-up studies into school-age is necessary to corroborate the result of this preliminary, while promising, small study. Advances in newborn intensive care since the time of the NICU intervention phase of the study have implications for the interpretation of the results also. Although the exact underlying mechanisms of NIDCAP effectiveness remain to be discovered, evidence from this study points to the intervention’s possible long-term effectiveness. Future research is required to validate the encouraging results reported and to determine the intervention’s effectiveness beyond school-age into adolescence and early adulthood.