Reduced prefrontal activation during Tower of London in first-episode schizophrenia: a multi-channel near-infrared spectroscopy study.

Cognitive impairments are considered as a core feature of schizophrenia and have been reported in associated with dysfunction of the prefrontal cortex (PFC). The Tower of London (TOL) task is a widely used neuropsychological test to assess the planning ability and the PFC function. In the present study, we examined functional changes in the PFC of 40 first-episode schizophrenia patients and 40 age- and gender-matched healthy controls by means of multi-channel Near-infrared spectroscopy (NIRS) during performance of the TOL task. NIRS is a noninvasive optical method that can measure relative changes in oxygenated ([oxy-Hb]) and deoxygenated ([deoxy-Hb]) hemoglobin in cortical tissue. Compared to the healthy controls, schizophrenia patients exhibited a significant decreased activation in the left PFC and poorer TOL performance. The results confirm the functional deficits of the PFC and impaired planning ability in first-episode schizophrenia patients and suggest that NIRS may be a useful clinical tool for evaluating PFC activation in psychiatric disorders.