Alterations in error-related brain activity and post-error behavior over time

This study examines the relation between the error-related negativity (ERN) and post-error behavior over time in healthy young adults (N=61). Event-related brain potentials were collected during two sessions of an identical flanker task. Results indicated changes in ERN and post-error accuracy were related across task sessions, with more negative ERN associated with greater improvements in post-error accuracy. This relationship was independent of any cross-sectional relationships between overall task performance, individual difference factors, including personality and self-efficacy, and indices of self-regulatory action monitoring. These results indicate that the relation between ERN and post-error accuracy remains intact and consistent regardless of variation in this set of individual difference factors previously associated with both of these indices of self-regulatory action monitoring, providing support for the strength, robustness, and persistence of this relationship in the process of adaptively controlling behavior to enhance task performance.     

Musculoskeletal status and disability of MMPI profile subgroups among patients with low back pain

The Minnesota Multiphasic Personality Inventory (MMPI) profiles of 205 male and 157 female patients with acute and chronic low back pain (LBP) were studied for replicable homogeneous subgroups using three cluster-analysis procedures. Two normal and three clinically elevated profile subgroups were identified. The two normal subgroups were characterized by relatively normal musculoskeletal condition and were least disabled, but they differed somewhat from each other in duration of pain, presence of physical abnormalities, and daily functioning. The third subgroup had the following characteristics: an elevated neurotic triad, greatest duration of symptoms, most abnormal physical findings, greatest limitation of motion, most pain complaints during physical examination, and the fewest number of intact functional activities. The fourth subgroup, with an elevated neurotic triad plus subclinical elevations on other scales, had somewhat less musculoskeletal impairment but had extensive work disability, financial compensation, and previous surgeries. The fifth and most pathologic profile subgroup surprisingly consisted largely of acute-pain patients whose musculoskeletal condition and daily functioning were similar to those of the normal subgroups. Patients in the three abnormal MMPI subgroups were exposed to more LBP physical-risk factors in the workplace. Implications for psychological treatment with these different profile types are discussed.