Cognitive genomics: Searching for the genetic roots of neuropsychological functioning.

Abstract

Objective Human cognition has long been known to be under substantial genetic control. With the complete mapping of the human genome, genome-wide association studies (GWAS) for many complex traits have proliferated; however, the highly polygenic nature of intelligence has made the identification of the precise genes that influence both global and specific cognitive abilities more difficult than anticipated. Methods Here, we review the latest developments in the genomics of cognition, including a discussion of methodological advances in the genetic analysis of complex traits, and shared genetic contributions to cognitive abilities and neuropsychiatric disorders. Results A wealth of twin and family studies have provided compelling evidence for a strong heritable component of both global and specific cognitive abilities, and for the existence of ‘generalist genes’ responsible for a large portion of the variance in diverse cognitive abilities. Increasingly sophisticated analytic tools and ever-larger sample sizes are now facilitating the identification of specific genetic and molecular underpinnings of cognitive abilities, leading to optimism regarding possibilities for novel treatments for illnesses related to cognitive function. Conclusions We conclude with a set of future directions for the field, which will further accelerate discoveries regarding the biological pathways relevant to cognitive abilities. These, in turn, may be further interrogated in order to link biological mechanisms to behavior.

Genetic influence on cognitive development between childhood and adulthood

“…Our findings also highlight the importance of g, or general cognitive ability, and lend support to the notion of generalist genes i.e., that a set of generalist genes influence multiple cognitive domains [63]. The generalist gene hypothesis has important practical implications since g can readily be calculated in any study that includes five or more cognitive tests, allowing combining of data from multiple studies and thus increasing power to detect genetic variants underlying cognition [26].…”

“…Between early adulthood and old age, on the other hand, heritability of processing speed and memory decreases [25]. Thus, genetic influences on cognition may vary, not as a linear function of age, but depending on the developmental period and the specific cognitive abilities under investigation [26]. While the moderation of heritability by age is well replicated [3], previous studies have been unable to fully disentangle this effect because age has been categorized into broad developmental periods, rather than investigated as a continuous factor.…”

Person-Based Brain Morphometric Similarity is Heritable and Correlates With Biological Features

“…Nevertheless our findings suggest the influence of “generalist genes,” that is genes or genetic factors that influence neuroanatomic variation across multiple rather than specific features of anatomy. Similar arguments have been made about the genetic architecture of general intelligence versus more specific domains of cognition (Bearden and Glahn 2017).…”

The role of RDoC in future classification of mentaldisorders

“…Finally, RDoC’s role as a flexible research framework serves as a model for further major revisions to conceptions of mental illness–in the near term, in such growing research areas as connectomics 13 and the genomics of functional systems 14 ; and in the longer term, potentially radical change stemming from computational modeling and machine learning. 15 , 16 …”