午夜剧场

"How can I motivate my child?" "Seeking highly motivated individuals." Words related to motivation are everywhere in our daily lives. You might see the former in educational settings and the latter in job hunting. High motivation is evaluated as a positive trait, while low motivation is something to be avoided. Motivation is also frequently addressed in clinical psychiatry. One of the core symptoms of depression is a lack of motivation, and a factor that hinders dementia rehabilitation is also motivational impairment. For these reasons, research to clarify what kind of brain activity supports motivation is upheld as a major pillar of neuroscience research.

In my laboratory, we study motivation using mice. Motivation in mice!? Readers might be wide-eyed with surprise. However, thanks to the contributions of psychology, motivation can be evaluated in both humans and experimental animals. Historically, a framework for motivation research using pigeons was established. Once they learn the relationship that pecking a lever with their beak yields food, a hungry pigeon will peck away wanting more food. For example, under the condition that food is given after 100 pecks, pigeons vary: some finish all at once, some work sluggishly, and some raise the white flag saying they cannot do it. The point here is that the state of mind called motivation is evaluated through attitude and behavior. Evaluating motivation in humans is also difficult; no matter how much someone says, "I will work with motivation," it cannot be evaluated without seeing them actually work. Furthermore, in addition to the manner of engagement, whether or not the initial goal can be achieved is also an evaluation point for motivation.

We use mice that have learned the relationship between pressing a lever and receiving food for our experiments. What we discovered through mouse research is that in order to act with motivation, one first needs the "will to start" (moving quickly into action), and goals can only be achieved when that will is combined with the "perseverance" to persist tenaciously. Furthermore, we discovered that the brain regions involved in the will to start and perseverance were different. Because the internal brain mechanisms for starting and persisting are different, it is possible to have a result like a "three-day monk" (a short-lived burst of effort) where there was initial motivation but no perseverance. To measure human motivation, just like with mice, there is nothing better than actually letting them try it.