The temporal change of activations in the visual target oddball stimulus

In recent years, many researchers have been studying activated regions in the brain using fMRI to investigate the source of brain activity for various sensory stimuli. However, previous reports have not necessarily been consistent. We examined the activation for a visual target task in the oddball paradigm as a first step to investigating sources associated with the functions of decision and recognition. In our analysis, we examined the activated area in the brain in three kinds of analysis time sections, from stimulus onset to 5 seconds after the stimulus (time section A), from 2 to 7 seconds (time section B) and from 4 to 9 seconds (time section C). In the temporal change, in the time section A, many activated areas could be seen. On the whole, the flow of activation from the parietal area activated in time section A to the prefrontal area activated in the time section B and C could be seen. It is considered from our results that various areas are involved in the visual target response.