Contributions of nonhuman primate research to understanding the consequences of human brain injury during development

Abstract

In this introductory review we first present a theoretical framework as well as a clinical perspective regarding the effects of early brain injury on the development of cognitive and behavioral functions in humans. Next, we highlight the contributions that nonhuman primate research make toward identifying some of the variables that influence long-term cognitive outcome after developmental disease, or damage. We start our review by arguing that in contrast to adult-onset injury, developmental brain insults alter the ontogenetic pattern of brain organization and circuit specialization depending on the variables of age at injury, the focality of the lesion, and the potential for reorganization. We then introduce the 2 nonhuman primate studies in this section (Kiorpes on vision; Bachevalier on cognitive memory), and highlight the relevance of their findings to our understanding of developmental conditions or injuries in humans, with the ultimate goal of improving the health and development of the young.

Neurocognitive Impairment in Ugandan Children with Sickle Cell Anemia Compared to Sibling Controls: A cross-sectional study

“…40 Similar findings were reported in a U.S. study, where SCA and social factors both influenced neurocognition. 28 The effect of age on neurocognitive outcome in our study could also be a consequence of ‘growing into deficit’ where effects of brain injury become apparent as the child grows older 51 .…”

“…28 The effect of age on neurocognitive outcome in our study could also be a consequence of "growing into deficit," where effects of brain injury become apparent as the child grows older. 52 A relatively high proportion of neurocognitive impairment in the older group of non-SCA siblings may be at least attributable to social issues, as all neurocognitively impaired siblings had caregivers with low education. Our group had previously reported this association among healthy children in Kampala.…”

“…28 The effect of age on neurocognitive outcome in our study could also be a consequence of “growing into deficit,” where effects of brain injury become apparent as the child grows older. 52…”

The Pair Test: A computerised measure of learning and memory

“…Importantly, early brain pathology interferes with the normal processes of circuit specialisation and hemispheric lateralisation (Willment and Golby, 2013 ), which are sacrificed to facilitate neural plasticity and, in turn, rescue cognitive functions (Cacucci and Vargha-Khadem, 2019 ). Compensatory reorganisation of function is facilitated by greater potential for plasticity following an injury in younger patients, thereby impeding, or abolishing the normal lateralisation process (Cacucci and Vargha-Khadem, 2019 ). Early-onset pathology and efficient neural plasticity therefore result in a pattern of non-specialised hemispheric organisation and, consequently, a diffuse representation of cognitive functions (Vargha-Khadem et al, 2000 ).…”