An fMRI study comparing brain activation between word generation and electrical stimulation of language-implicated acupoints

We compared the brain activation on functional magnetic resonance imaging (MRI) during word generation with the activation during electrical stimulation of two language-implicated acupoints in 17 healthy, Mandarin-speaking, Chinese male volunteers (age 19-26 years). All subjects were strongly right handed according to a handedness inventory. Using a standard functional MRI procedure and a word-generation paradigm, significant activation was seen in the left and right inferior frontal gyri (BA 44, 45) as well as the left superior temporal gyrus (BA 22, 42). Stronger activation with a larger volume was seen in the left hemisphere. Electrical stimulation of either one of the two language-implicated acupoints, SJ 8 (11 subjects) and Du 15 (6 subjects), without the word-generation paradigm in the same cohort, produced significant activation in the right inferior frontal gyrus (BA 44, 46) and in the left and right superior temporal gyri (BA 22, 42), respectively. Nevertheless, no activation was seen in the left inferior frontal gyrus. In addition, electrical stimulation of the adjacent non-acupoints did not produce any significant brain activation. Although our results support the notion of acupoint-brain activation, applying acupuncture at SJ 8 or Du 15 does not activate the typical language areas in the left inferior frontal cortex.