According to a study conducted by Mika and his colleagues, prolonged stress in rats causes response inhibition. It was evident through their experiment that stressed rats had inhibited premature responses (decreased timing of intervals to food), along with decreased intrinsic motivation to initiate a response. They link the decreased motivation to the stress-associated reduction in incentive motivation, as presented by another study conducted by Kleen and his colleagues. Decreased motivation was also seen in a study conducted by Beery and Kaufer, where they explained that stressed rodents are less likely to be motivated to interact with one another.