None of the behavioral measures used in the current experiments examined aspects of human novelty seeking that reflect self-reported interoceptive states, such as fickleness or extravagance. To the extent that they reflect responses to novelty given the complex interactions of novelty, neophobia, anxiety, and activity, these tasks may most closely correspond to one of four subdimensions named by the Tridimensional Personality Questionnaire (1, 11) and elaborated in the Temperament and Character Inventory (12), called exploratory excitability. However, the traditional indices of rodent exploration, activity in a novel environment and head dipping on a hole-board, measure behaviors qualitatively different from those in the novel environment preference test, which relies on the overt expression of preference for the novel compartment. This last test could reflect some aspects of the impulsivity component of novelty seeking, because the expression of preference will be influenced by latency to enter the novel compartment.
