Habituation of responding for food in humans

Habituation to repeated food stimuli has been demonstrated in various response systems across animals and humans. Patterns of responding to obtain food demonstrate many empirical characteristics of habituation, and the purpose of the present study was to determine whether motivated responding for food in humans follows an habituation pattern. Thirty-five nonobese men were randomized to groups in which they responded to gain access to repeated presentations of the same food or presentations of a variety of isocaloric food. Subjective ratings of food liking and hunger were assessed. Consistent with habituation theory, participants working for one type of food demonstrated a more rapid decrease in responding for food and in ratings of liking of the repeatedly presented food than participants working for varied foods. All participants showed similar reductions of hunger and resumed responding for a novel food stimulus. This study documents that motivated responding for food in human shares characteristics of an habituation process.