Brain activities tell us what animals have in mind

Abstract

Recent human neuroimaging studies indicate that by using fMRI we can “see” what people are thinking. In animals, we can more accurately see what the animal has in mind by using invasive methods that cannot be used in human subjects. Here I introduce experimental studies where single neuronal activities were examined in the monkey prefrontal cortex in relation to working memory and reward expectancy. We found that by monitoring the neuronal activity while the animal is waiting for the next event, we can see what the monkey is retaining or expecting in mind. Human neuroimaging studies have well documented “default mode of brain activity”, which is higher activity during the resting state than during cognitively demanding task, and is concerned with internal thought processes, in the medial prefrontal and medial parietal areas. In our PET study, we also found higher activity during rest in these medial cortical areas of the monkey. The result suggests that there are primitive-level internal thought processes in the monkey.View full abstract