Measurement of premorbid intellectual ability following brain injury.

Prediction of premorbid intellectual ability in brain-injured patients was investigated using two sets of regression equations and the Intellectual Correlates Scale (ICS). Eighty subjects completed the WAIS-R and the ICS. The four subject groups included a control group and right-hemisphere, left-hemisphere, and diffuse brain-injured groups. As expected, brain-injured groups obtained lower IQs than controls. Also, estimated IQs approximated obtained IQs for controls, while overestimating IQs for brain-injured groups. Support was provided for the continued use of the Barona, Reynolds, and Chastain (1984) and the Barona and Chastain (1986) regression equations as measures of premorbid intellectual functioning. Previous findings (Schlottmann & Johnsen, 1991), suggesting the ICS may also serve as a measure of premorbid intellectual functioning, were not replicated.