This study proposes a neural mechanism hypothesis for qualitative changes in human cognitive ability, exploring the key features that may exist in human infant brain development that are fundamentally distinct from other species. This unique neural structure that develops postnatally is the decisive factor for humans to acquire language and abstract thinking abilities. Human infants exhibit extensive neuronal migration phenomena in white matter that persist for nearly 18 months after birth, accompanied by a surge in brain volume and enhancement of language and cognitive abilities. The traditional view holds that these neurons originate from the fetal ventral telencephalic region, but animal studies have found that this time period is close to the termination of neurogenesis and cannot adequately explain its scale and duration.The hypothesis posits that these neurons have an alternative source. In mammals, hippocampal neurogenesis reaches its peak during the perinatal period to the first few months after birth. Under the stimulation of information and learning tasks in the human environment, hippocampal neurogenesis and neuronal survival rates are significantly enhanced. Within a brief period, the number of surviving neurons exceeds the hippocampus's capacity, resulting in massive overflow of neurons from the hippocampus to white matter regions, where they migrate with the migratory stream to the forebrain cortex and interconnect to form new neural networks.This may be a developmental mechanism unique to humans, where hippocampal neuronal overflow becomes the key process for humans to develop distinctive neural structures. Humans and other animals exhibit fundamental differences in cognitive abilities due to differences in neural structure.
Jue Wang (Tue,) studied this question.