Cognitive slowing in patients with acquired brain damage: An experimental approach

Nine brain-damaged patients (19-54 years old) with ''cognitive slowing'', and 10 healthy subjects (26-56 years old) were tested with a slightly modified version of a Sternberg memory task (varied-set procedure). Cognitive slowing in the sense of reduced information-processing speed is reflected by mean RTs and slopes and intercepts derived from the RTs as a function of memory set size. Patients showed a marked increase of these parameters. While the results obtained from the control subjects are in accordance with typical Sternberg findings, patients showed no parallel regression lines for positive and negative responses. As an alternative explanation for this result an extended ''self-terminating'' process is proposed that also appears to be helpful in explaining the overall cognitive slowing in the patients.