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Cognitive genomics (or neurative genomics) is the sub-field of genomics pertaining to cognitive function in which the genes and non-coding sequences of an organism's genome related to the health and activity of the brain are studied. By applying comparative genomics, the genomes of multiple species are compared in order to identify genetic and phenotypical differences between species. Observed phenotypical characteristics related to the neurological function include behavior, personality, neuroanatomy, and neuropathology. The theory behind cognitive genomics is based on elements of genetics, evolutionary biology, molecular biology, cognitive psychology, behavioral psychology, and neurophysiology. Intelligence is the most extensively studied behavioral trait.[1] In humans, approximately 70% of all genes are expressed in the brain.[2] Genetic variation accounts for 40% of phenotypical variation.[3] Approaches in cognitive genomics have been used to investigate the genetic causes for many mental and neurodegenerative disorders including Down syndrome, major depressive disorder, autism, and Alzheimer's disease.

Cognitive genomics testing[edit source] Approaches[edit source] Evo-geno[edit source] The most commonly used approach to genome-investigation is evolutionary genomics biology, or evo-geno, in which the genomes of two species which share a common ancestor are compared.[4] A common example of evo-geno is comparative cognitive genomics testing between humans and chimpanzees which shared an ancestor 6-7 million years ago.[5] Patterns in local gene expression and gene splicing are examined to determine genomic differentiation. Comparative transcriptomic analyses conducted on primate brains to measure gene expression levels have shown significant differences between human and chimpanzee genomes.[4] The evo-geno approach was also used to verify the theory that humans and non-human primates share similar expression levels in energy metabolism-related genes which have implications for aging and neurodegenerative disease.[4] Evo-devo[edit source] Evolutionary development biology (evo-devo) approach compares cognitive and neuroanatomic development patterns between sets of species. Studies of human fetus brains reveal that almost a third of expressed genes are regionally differentiated, far more than non-human species.[4] This finding could potentially explain variations in cognitive development between individuals. Neuroanatomical evo-devo studies have connected higher brain order to brain lateralization which, though present in other species, is highly ordered in humans. Evo-pheno and evo-patho[edit source] Evolutionary phenotype biology (evo-pheno) approach examines phenotype expression between species. Evolutionary pathology biology (evo-patho) approach investigates disease prevalence between species.