Chunk #147 — 10.0 Where Do We Go From Here? — 10.4 More research on the utility of an endophenotype — 10.4.2 Enhancing our understanding of brain mechanisms
We are arguing here that, in light of what we have learned from a decade of GWAS, endophenotype research needs to move beyond merely establishing that a candidate endophenotype marks genetic risk, with the underlying assumption that this will lead to genetic discoveries. Although genetic discovery is possible, the available evidence strongly suggests that it is unlikely without larger sample sizes or a technological revolution in our ability to conduct electrophysiological research much more efficiently. Nevertheless, endophenotype research can enhance our understanding of brain mechanisms accounting for individual differences in endophenotype level or configuration (criterion #8). Parametric manipulations of experimental parameters (e.g., Curtis, Calkins, Grove, Feil, & Iacono, 2001; Salisbury et al., 1994) may be able to provide experimental evidence about parameters affecting an endophenotype. For instance, a modified version of the Eriksen flanker task has been used in which target-distractor incompatibility was parametrically varied in order to probe the sensitivity of the N2 ERP component to the degree of response conflict subjects experience when presented with a particular variant of the stimulus array (Forster, Carter, Cohen, & Cho, 2011).
