age) and adulthood (from 20 to 60 years of age and older), consequently (Kang, et al., 2011). In another study, two orders of magnitude more gene expression differences (or the number of significantly differentially expressed genes) were detected across cortical areas of fetal brain compared with the adult human cortex; a subset of those genes are known to be involved in the control and development of higher cognitive functions (Johnson, et al., 2009; Lambert, et al., 2011). For instance, the genes that are considered to be candidates for studies of speech and language abilities and disorders (such as FOXP2, CNTNAP2, and CNTNAP5) were found to be especially enriched in the perisylvian cerebral area – the main cortical region that contains the functional domains controlling speech and language – of the fetal brain (Abrahams, et al., 2007; Johnson, et al., 2009).
