Table 1.

The six stages of the differential cognitive neuroscience framework.

1. Identify possible endophenotypes for the trait of interest (here, extraversion).

2. Gather evidence to test whether the endophenotypes and the trait are associated/correlated.

3. Use cognitive neuroscience/computational models, and particularly those which have potentially biologically identifiable parameters, to simulate the target endophenotype (or processes contributing to endophenotypic variance).

4. Carry out the “individual differences” simulations of the endophenotype (or endophenotypic processes). This is done by allowing several “psychobiologically interpretable” candidate parameters to vary in the model, one by one. This sensitivity analysis is carried out to identify the best (i.e., most plausible) of the candidate parameters, using psychometric criteria.

5. Test the most plausible, specific model parameters for their ability to simulate variation in other distinct, but conceptually related, endophenotypes.

6. Explore whether, and in what contexts, the proposed parameter variation can simulate aspects of extraverted behavior in “toy” models.