Awareness of errors in naturalistic action after traumatic brain injury

A prospective study was performed to develop a method for assessing "on-lin e" error detection and correction during performance of naturalistic action , to determine whether traumatic brain injury (TBI) affects error detection and correction, and to compare actual task performance with verbal self-ra tings of performance. Participants included 18 persons who had sustained se vere TBI from 34 to 186 days prior to study and who were comparable to cont rols in their rate of naturalistic action error, along with 18 control subj ects chosen to be demographically comparable to subjects with TDI. Subjects performed two different tests of naturalistic action in which they complet ed everyday activities leg, wrapping a gift, making toast) at different lev els of complexity, as manipulated by the addition of distractor objects, th e number of tasks that had to be completed per trial, and other demands on planning and working memory. Using a specially developed coding system, eac h error on these tasks was scored as to whether the subject corrected it an d whether the subject otherwise demonstrated awareness of the error. Error scores were also compared to subjects' responses to a questionnaire in whic h the) rated their own performance on the most challenging level of the nat uralistic action test. In general, subjects with TDI corrected and showed a wareness of proportionally fewer of their errors when compared to controls. Qualitative patterns for some error types also differed between groups. De spite making more errors than control subjects on the most challenging task , subjects with TBI did not rate themselves as performing more poorly with respect to its cognitive demands. However, for subjects with TBI, the numbe r of errors was correlated with performance ratings on certain questionnair e items. This study showed that error detection and correction can be relia bly measured during naturalistic action and appear to be impaired in severe TBI even when the base rate of error is controlled. TBI may affect error d etection and correction by reducing, or impairing the allocation of, attent ional resources needed for the simultaneous execution and monitoring of rou tine action.