Task set switching in schizophrenia

The authors used a task-switching paradigm to investigate set shifting abil ity in schizophrenia. This paradigm included 2 choice reaction time (RT) ta sks: up-down and right-left. Switching tasks were associated with costs (i. e., longer RT in task-switch trials than in task-repetition trials); patien ts responded more slowly than controls and suffered greater switching costs , were as efficient as controls in engaging in an upcoming task set, and we re faster than controls in disengaging from the previous task set. There we re indications that patients quickly forgot what each keypress indicated, m aking it necessary for them to acquire response meaning information anew in each trial. To test this notion, the authors subsequently tested normal pa rticipants in conditions in which response meaning information needed to be acquired anew in each trial. These participants produced a pattern of swit ching costs resembling that of patients. Results suggest that set switching difficulties in schizophrenia, as exhibited in the present paradigm, refle ct poor memory for task context information.