Questions

• Why do we eat/drink even when we are not hungry/thirsty? Consumption behaviors can be well triggered beyond the homeostatic need. For example, we can eat not only because of hunger/thirst but also for pleasure, which is called “hedonic consumption”. And oftentimes hedonic consumption can lead to excessive energy intake, one of the major contributors to obesity and diabetes nowadays. Understanding its neural mechanism is therefore critical to help to reduce overeating in the context of our current environment which abounds with inexpensive, palatable, high-calorie foods and beverages.

• Our brain can actively detect external stimulus in our living environment, gets the internal representation of these external stimuli, and generate the appropriate behaviors to firstly ensure our survival and secondly maximize our living quality. But the attributes of a stimulus are not objective physical characteristics of the stimulus. Instead, the relevance of the stimulus depends on changing internal states and the brain’s history with similar situations. This situational relevance is not a small matter but has a profound effect on neural activities in the brain and its relationship to the sensory environment. The same stimulus under this situation can evoke very different neuronal patterns in different brains or even the same brain at different times, which is often underlying the behavior variation within individuals and also the social dynamics in populations. So how do internal states modulate behavior output? How does behavior diversity rise in the face of the same environment? We are interested to use hunger/thirst as entry points to understand how internal information is integrated into the internal representation of external stimuli and changes the final behavior output.