Similar activation patterns in the prefrontal cortex for Chinese and Japanese verbal fluency tests with syllable cues as revealed by near-infrared spectroscopy

The verbal fluency test (VFT) is utilized in neuropsychology to evaluate the cognitive function of the prefrontal cortex (PFC) in the human brain. We present a novel Chinese VFT similar to the established Japanese VFT; both tests prompt a syllable to the subject. However, it was uncertain whether the Chinese VFT can activate the PFC and whether PFC activation patterns are similar between the two tests. Here we administered the Chinese VFT to 30 native Chinese speakers and the Japanese VFT to 30 native Japanese speakers. We used near-infrared spectroscopy (NIRS) to observe PFC activation. Then we compared the similarities between the Chinese VFT and the Japanese VFT. The subjects generated an average of 12.8 ± 4.7 words during the Chinese VFT. NIRS indicates that the concentration of oxygenated hemoglobin during the test was significantly higher than those before and after the test. It exhibited similar PFC activation patterns with the Japanese VFT. The novel Chinese VFT can activate the PFC in the human brain effectively in Chinese speakers. Our work thus provides the first validated phonetically cued Chinese VFT, unique from other not strictly phonemic Chinese VFTs, and facilitates the diagnosis of various PFC-related cognitive impairments.