Persistent hunger for sodium makes brain stimulation not so sweet: theoretical comment on Morris et al. (2006).
The rewarding value of a stimulus is not fixed but rather is subjective and can vary with motivational state. M. J. Morris, E. S. Na, A. J. Grippo, and A. K. Johnson (2006) report that generating a prolonged sodium appetite decreases the rewarding value of lateral hypothalamic brain stimulation and sucrose intake. The findings support the idea that a specific motivational state can have strong, nonspecific consequences for reward processing.