Magnetoencephalographic study of frontal lobe function in stimulus processing and response inhibition using Go/No-Go paradigm

The brain mechanisms underlying stimulus processing and response inhibition were studied by recording magnetoencephalographic (MEG) responses in the frontal lobe using a visual Go/No-Go paradigm in 12 healthy volunteers. Response-selection-related MEG activities were observed as two peaks in root-mean-squares (RMSs) of magnetic fields of 50 and 150 ms latencies after response onsets over the left motor and prefrontal areas and response-related MEG activities were observed during a few hundreds of periods after stimulus onsets in the frontal area. These results were interpreted to suggest ongoing brain activities for response selection and response execution processes even after overt behavioral responses.